A row of clear glass vaccine vials with a syringe resting against them on a grey background

Are You Still Protected From Measles? The 1963 to 1967 Vaccine Gap and What Adults Should Do

On October 8, 2026October 28, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Pennsylvania crossed a thousand measles cases this week. The state is at 1,078 across 41 counties, with 207 hospitalizations and five measles-associated deaths, and Lancaster County alone accounts for 401 of them. Nationally we are at roughly 3,880 cases. That is the highest annual total since 1991.

New York’s governor declared a disaster emergency on Monday so that paramedics, pharmacists and midwives can give vaccines. Florida’s health department held a hearing in Orlando on October 8 on dropping hepatitis B, chickenpox, Hib and pneumococcal from its school and daycare requirements. Measles is not among them. The MMR requirement is written into state statute, so only the legislature can touch it. Comment on the other four closed on October 19 and the rule has not been adopted.

Almost all of the coverage is about children, because that is where the cases are.

I have had one of these myself, by video. An unvaccinated child, high fever, body aches, and a rash whose appearance made me think measles before I thought of anything else. Looking like measles is not the same as being measles. Confirmation takes a swab for PCR and a blood sample for measles IgM, and neither of those travels down a camera, so that visit ended where it had to end, in a referral for testing in person.

That is the honest limit of the work I do. I could recognize it. I could not prove it.

The question I get by video is a different one, and it comes from adults. Some version of: am I still covered?

It is a better question than it sounds, because for a specific group of people the honest answer is no.

The 1963 to 1967 problem

There were two measles vaccines licensed in 1963. One was a live attenuated vaccine, which is the ancestor of the MMR we give now. The other was an inactivated vaccine, a killed-virus product that was pulled from the market in 1967 because it did not work well enough.

It did something worse than not working. Some people who got the killed vaccine and later met the real virus developed atypical measles syndrome, an unusually severe illness with high fever, an odd rash that starts on the extremities, and pneumonia.

So the guidance is specific. Anyone vaccinated before 1968 with killed measles vaccine, or with a vaccine of unknown type, should be revaccinated with at least one dose of live attenuated measles vaccine. If you are in a high-risk group, that becomes two doses.

The number of people affected is small. The CDC puts it at under five percent of adults. Immunize.org estimates fewer than a million Americans.

Here is the practical problem with a small number. Almost nobody born in that window knows which shot they got. The record, if it exists at all, is a line in a pediatrician’s file from sixty years ago, and that pediatrician has been retired for thirty of them. “Measles vaccine, 1965” does not tell you which product it was.

Which is why the rule says unknown type counts the same as known killed. If you cannot establish it was the live vaccine, you are treated as though it was not.

If you were born before 1957

You are presumed immune and you do not need anything.

That cutoff is not a guess about vaccines. It is a statement about how common measles was. Before the vaccine existed, essentially everyone caught it in childhood, so the assumption is that you already did, whether or not you remember it.

One exception, and it is the one that applies to me and to anyone else reading this who works in health care. For healthcare personnel, facilities should consider vaccinating staff born before 1957 who have no laboratory evidence of immunity and no laboratory confirmation of past disease. The presumption is good enough for the general public. It is not good enough for someone standing in a room with a febrile child.

Should you get a titer drawn?

Usually not, and this is where I disagree with how the question is often handled.

The CDC does not recommend routinely screening adults for measles immunity outside an outbreak area, and it does not recommend testing after vaccination to confirm it took. If you have documentation of two MMR doses, you are done. No blood draw adds anything.

A titer is useful in one specific situation, which is when you genuinely do not know your history and the result would change what happens next. Positive measles IgG means immune. Negative or equivocal means treat as non-immune, unless you meet one of the other criteria such as birth before 1957.

But consider the arithmetic before you order it. An MMR dose costs less than the antibody test in most places, takes one visit instead of two, and carries no penalty if you turn out to have been immune all along. An extra dose in someone who is already protected does nothing at all. It does not boost, it does not harm, it simply has no target.

So for most adults who are uncertain, getting the shot is faster and cheaper than proving you do not need it.

The exception worth naming is pregnancy. MMR is a live vaccine and is not given during pregnancy, so a woman who is pregnant and uncertain about her status gets the titer instead, and the vaccine afterward if she needs it.

About the death count, since you will see it argued about

Pennsylvania reports five measles-associated deaths this year. The CDC’s national count is two, and the CDC’s database does not say which states those two are in.

That gap is real and it is worth understanding, because it is being read as evidence of a cover-up in one direction and of inflated numbers in the other.

The mechanism is duller than either. The CDC moved to counting measles deaths from National Center for Health Statistics mortality data, which is built from death certificates and lists an underlying cause, rather than from state health department reports. NCHS data is designed to measure long-term trends across a population. It was not built to adjudicate individual infectious disease cases in the middle of an outbreak, and it runs on a slower clock, which is the substance of what the outside experts objecting to the change have said.

Pennsylvania uses a different definition: a laboratory-confirmed measles infection and death within thirty days of symptom onset, absent an obvious unrelated cause such as a car crash.

Both definitions are defensible. They will produce different numbers during a fast-moving outbreak, and the federal one will lag.

There is also a political layer, which I will describe rather than referee. The CDC initially included Pennsylvania’s first two deaths and then removed them pending review, after the Health Secretary publicly questioned whether measles had caused them. That detail was first reported by a Substack citing an anonymous CDC employee, so I hold it more loosely than the rest of this. The count later returned to two after NCHS verified one death. Pennsylvania has since conditioned its request for federal Epi-Aid assistance on the CDC publicly recognizing the state’s full count.

What I would say clinically is narrow. Of Pennsylvania’s five, two were unvaccinated adults, aged 18 and 40, and two were infants too young to be vaccinated. That pattern is what measles mortality has always looked like. It kills the unprotected and the too-young-to-protect, and it does so through pneumonia and encephalitis rather than through the rash anyone remembers.

As the infectious disease physician Amesh Adalja put it, to the public a gap like this looks like either incompetence or concealment. Neither is true here, and the fact that neither is true is not doing much to help.

What I would actually do

If you have records showing two MMR doses, nothing. You are protected and the protection does not fade.

If you were born before 1957 and do not work in health care, nothing.

If you were vaccinated between 1963 and 1967, or you have no idea what you got and you were born after 1957, get one dose of MMR. Do not spend three weeks trying to find a sixty-year-old paper record first.

If you are pregnant and uncertain, ask for the titer, and plan the vaccine for after delivery.

And if you have an infant under twelve months in a household traveling to an outbreak area, that is a real conversation with your pediatrician about an early dose, which is a thing that exists and is not widely known.

The Bottom Line

Measles is at a thirty-five year high, and the people getting sick are overwhelmingly children who were never vaccinated. That is a different problem from the one most adults are asking me about.

For adults, the short version is that the vaccine works, it does not wear off, and the only real gap is a four-year window in the sixties when a product that did not work well was in use. If you fall in that window or you simply cannot establish what you got, a single MMR dose closes it, and it is cheaper and faster than proving you were fine all along.

Sources

Pennsylvania Department of Health Provides Statewide Update on Measles Outbreak as Cases Reach 1,078 in 41 Counties. Pennsylvania Department of Health, October 7, 2026. https://www.pa.gov/agencies/health/newsroom/pa-department-of-health-provides-statewide-update-on-measles-out9
Measles cases surpass 1,000 in Pennsylvania amid the state’s largest outbreak in decades. ABC News, October 2026. https://abcnews.com/Health/measles-cases-surpass-1000-pennsylvania-outbreak-continues-spread/story?id=137002024
Pennsylvania confirms fifth measles-associated death as US outbreak grows. Al Jazeera, September 30, 2026. https://www.aljazeera.com/news/2026/9/30/pennsylvania-confirms-fifth-measles-associated-death-as-us-outbreak-grows
New York governor declares measles emergency. CT Mirror, October 7, 2026. https://ctmirror.org/2026/10/07/new-york-measles-emergency-hochul
Vaccine change may bring largest measles outbreak ever. WGCU, October 7, 2026. https://wgcu.org/health/2026-10-07/vaccine-change-may-bring-largest-measles-outbreak-ever
Measles Cases and Outbreaks. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/data-research/index.html
Measles Vaccine Recommendations. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html
Questions About Measles. Centers for Disease Control and Prevention. https://www.cdc.gov/measles/about/questions.html
Ask the Experts: MMR (Measles, Mumps, and Rubella). Immunize.org. https://www.immunize.org/ask-experts/topic/mmr/
Measles Prevention: Recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR. https://www.cdc.gov/mmwr/preview/mmwrhtml/00041753.htm
CDC’s new tracking method for measles deaths puzzles experts. CIDRAP, University of Minnesota. https://www.cidrap.umn.edu/measles/cdc-s-new-tracking-method-measles-deaths-puzzles-experts
Measles is spreading across the US and officials can’t agree on the death toll. The Conversation, 2026. https://theconversation.com/measles-is-spreading-across-the-us-and-officials-cant-agree-on-the-death-toll-293234
Changes to CDC Vaccine Recommendations in 2025 and 2026. Congressional Research Service, IN12684. https://www.congress.gov/crs-product/IN12684

An empty hospital corridor lit by daylight from a row of windows, with no people present

The Plague Death in Irkutsk: What We Know, What Russia Won’t Say, and Whether Americans Should Worry

On October 6, 2026October 6, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Written October 6, 2026. This story is five days old and still moving. Dates and numbers below are what could be verified as of this morning.

A patient put it to me plainly on a video visit: do we have to be worried about a new pandemic with the Russia plague that is in the news?

Fair question. I did not give them a clean yes or no, because five days into something like this, anyone offering a clean yes or no is guessing.

Here is what I can tell you, and more usefully, here is what nobody can tell you yet.

A 28-year-old lab tech, four days, and a death certificate that says pneumonia

Darya Shipilova was 28 years old and worked as a laboratory technician at the Irkutsk Anti-Plague Research Institute in Siberia. On September 25, according to Russian media reporting, she broke a test tube of live bacteria while collecting samples. She was admitted to the hospital on September 29 with what her chart called pneumonia of unknown etiology. She died either October 1 or October 2, depending on which outlet you read, and the fact that we cannot pin down the date a woman died is itself a small piece of information about how much is being released.

Four days from the reported accident to the hospital. Two days from the hospital to the morgue.

Then the response. Roughly 197 people who had contact with her were identified, and 189 of them were hospitalized for observation, 114 at one facility, 63 at another, and 12 sent to the anti-plague institute itself. Contacts were isolated in a center that had been used for COVID patients. FSB officers started escorting the ambulances. By October 4 and 5, City Clinical Hospitals No. 1, No. 3 and No. 10, the Ivano-Matreninskaya Children’s Hospital and at least one maternity hospital in Irkutsk were under three-week quarantine.

That is a plague response. Three weeks is not an arbitrary number, it is roughly what you choose when you want to clear the incubation period of something serious and then clear it again.

The part of this that got reported backward

A lot of the coverage I have seen, and the version most people have in their heads, is that Russia said a test tube broke.

Russia said no such thing. Rospotrebnadzor, the state public health agency, has stated there was no accident involving pathogenic microorganisms at the institute, that no microorganisms associated with her professional work were found in her body, and that the epidemiological situation in Irkutsk and Shelekhov is stable. Her cause of death, officially, is pneumonia of unknown cause.

The broken test tube came from her. It is what she reportedly told the medical staff who admitted her, and it reached the public through Russian media rather than through any official channel.

So the official position is not that there was an accident. The official position is that nothing happened. Hold that next to the children’s hospital being closed for three weeks and you have the actual story of the past week. Plague has still never been publicly lab-confirmed in this case. Meanwhile the governor of Irkutsk Oblast, Igor Kobzev, met with Russia’s chief public health officer about “reports of a suspected case of a particularly dangerous infectious disease,” and the head of neighboring Buryatia said out loud that the death was linked to plague before his statement was quietly amended to something softer.

Two different words that look identical

Worth separating, because it explains some of the panic.

“Plague” means a specific bacterium, Yersinia pestis, which causes bubonic, septicemic and pneumonic disease and which has a known treatment. “Plague” also means, in ordinary English, any catastrophe that sweeps through a population. When a headline says plague in Russia, a sizable fraction of readers are not picturing a gram-negative coccobacillus that responds to doxycycline. They are picturing 1348.

Both meanings are legitimate. Only one of them is a diagnosis.

Could a broken tube really do this?

This is the question I find most interesting clinically, and the honest answer is that it is a stretch.

Simon Clarke, a cellular microbiologist at the University of Reading, put it about as well as it can be put: “an awful lot must have gone wrong for a lab worker to be infected by a broken test tube.” Work with a select agent happens inside layered containment. Biosafety cabinets, directional airflow, respiratory protection, procedures that assume breakage will eventually happen because over enough years it does. A tube hitting the floor inside a functioning cabinet is a cleanup problem, not an exposure. For that breakage to seed a fatal pneumonia, she likely had to be outside containment, or the containment had to be failing, or she inhaled a bolus at close range before anything could capture it.

Which brings up the thing I keep coming back to.

If she broke that tube on September 25 and knew it, she should have been on post-exposure prophylaxis within hours. The CDC’s recommendation is seven days of monotherapy: doxycycline 100 mg every 12 hours, or ciprofloxacin 500 to 750 mg every 12 hours, with levofloxacin and moxifloxacin now also first-line. That is it. Oral pills, generic, sitting in any pharmacy in the world including the one inside an anti-plague institute. Given promptly, the odds she ever became symptomatic drop toward nothing.

She presented on September 29.

I do not know whether she was offered prophylaxis and declined it, or reported the break late, or reported it immediately to someone who decided it did not warrant treating, or was treated and failed. Any of those is possible. What I would say plainly is that the four-day gap, not the bacterium, is the most likely reason a healthy 28-year-old died. Untreated pneumonic plague kills most of the people it infects, and it kills them fast. The treatment window is measured in hours after symptoms start, not days. Once you are four days past an inhalational exposure and presenting with pneumonia, antibiotics are being asked to do something they are not very good at.

That is a boring explanation. It is also the one that requires nothing unusual to be true.

Was it resistant? Was it modified?

Here is where I think the public conversation is making an understandable mistake.

You do not need an engineered organism to explain a fast death. You need a late diagnosis, which we appear to have. Adding a modified pathogen to the story explains something that is already explained.

That said, drug-resistant plague is not hypothetical, and this is the fact I would most want people to walk away with. In 1995 a patient in Madagascar with ordinary bubonic plague yielded an isolate called IP275, the first multidrug-resistant Y. pestis ever found. It carried a self-transmissible plasmid, pIP1202, conferring resistance to at least eight drugs used in plague treatment and prophylaxis, streptomycin and tetracycline and chloramphenicol and the sulfonamides among them. Nobody built it. The plasmid backbone turned out to be nearly identical to resistance plasmids from Salmonella Newport and from a fish pathogen, meaning Y. pestis had picked it up from the enormous reservoir of resistance circulating in agricultural bacteria.

Resistant plague already happened, once, by accident, in a patient in 1995. That is a better reason to pay attention than anything anyone has alleged about Irkutsk. We already live with the mature version of this problem in drug-resistant tuberculosis, and nobody had to engineer that either.

As for whether this particular organism was modified: there is no public evidence of it, and there is one piece of evidence against the scenario people fear most. If this were a highly transmissible engineered strain, those 197 contacts would be the first sign. As of the Rospotrebnadzor statements, they were not showing signs of illness. No secondary cases have surfaced publicly. A pathogen built to spread does not stop at one person.

The institute, and the thing that is actually true about it

The Irkutsk Anti-Plague Research Institute of Siberia and the Far East traces to a plague laboratory set up in Irkutsk in 1923 and was formally established in its current form on June 5, 1934. Its job, for ninety years, has been surveillance and containment of plague and other dangerous infections across Siberia and the Russian Far East. Plague is genuinely endemic in Central Asian rodent populations. An institute like this is the reason outbreaks there stay small.

And yes, the Soviet anti-plague network has a documented connection to Biopreparat, the covert Soviet offensive biological weapons program that weaponized plague, anthrax and tularemia. Igor Domaradskiy, one of Biopreparat’s founders, had previously run the anti-plague institutes at Irkutsk and Rostov-on-Don. That is history, not allegation.

What does not exist is any public evidence that the Irkutsk lab is developing plague as a weapon today, or that this death is connected to an offensive program. A facility with a Cold War lineage working on a pathogen endemic to its own region is not, by itself, a weapons story.

Running the conspiracy theories down

These deserve a real answer rather than a wave of the hand, so here they are, from least to most plausible.

It was deliberately released. No. There is no reason to release a weapon into your own closed city, kill one of your own technicians, and quarantine your own children’s hospital.

It is an engineered superbug and the contacts are already dying in secret. This requires 189 hospitalized people, their families and the staff of five medical facilities to all stay silent. Irkutsk has a population over 600,000 and functioning messaging apps. Containment of information at that scale fails, and it fails fast.

It is not plague at all, it is something worse they will not name. Possible in principle, and it is the theory I can least firmly rule out, because no confirmatory testing has been published. But the response fits plague. The duration of the quarantine fits plague. An institute that works with Y. pestis having a Y. pestis accident is the least exotic available explanation.

There is a much bigger outbreak than they are admitting. Partially plausible, and I would not be shocked. Not because of anything specific to Irkutsk, but because this is a system that denied the test tube ever broke while sealing hospitals. Under-reporting is the house tendency.

An ordinary lab-acquired infection, recognized late, in a bureaucracy whose first instinct is denial. This is almost certainly what happened. Every observed fact fits it: the four-day delay, the speed of death, the aggressive contact tracing, the official denial, the walked-back statement from Buryatia, the pneumonia-of-unknown-cause diagnosis that nobody has updated. Boring, tragic, and entirely consistent.

Can we believe them?

On the specifics, no. On the response, mostly yes.

Watch what a government does rather than what it says. Russia’s words say stable and nothing happened. Russia’s actions say particularly dangerous infection, and they committed real resources to a real containment operation. When those two diverge, believe the resources.

The US State Department’s comment struck me as about right: “Many details have not been confirmed. We encourage Russian authorities to share accurate information quickly and openly,” alongside the observation that plague “is a known disease and is treatable with common antibiotics.” The CDC says it is monitoring. President Trump said his administration is looking at it very strongly and that “anybody that has that kind of a problem, we’re always willing to help,” which, whatever else you think of it, is the correct posture toward an outbreak in a country you are not friendly with.

Clarke’s line about what actually controls an outbreak is the one worth keeping: transparency, rapid diagnosis, effective contact tracing. Russia is doing two of the three.

Is this the next COVID?

No, and I want to be specific about why, because “no” by itself has stopped persuading anyone and I understand why.

A lot of people came out of 2020 believing that COVID began in a laboratory. Whether or not that is what happened, and it remains genuinely unresolved, that belief is the reason a Siberian lab accident in 2026 lands differently than it would have landed in 2015. People are not being irrational. They are pattern-matching to the last five years, and they have been told before that there was nothing to see.

So, the differences that matter.

Yersinia pestis is a bacterium. SARS-CoV-2 is a virus. That distinction is not academic: we have had effective antibiotics against plague since the 1940s, every pharmacy stocks doxycycline, and treatment is cheap and oral. There was no equivalent for COVID in February 2020, which is why the whole fight there moved to vaccination instead of treatment.

Pneumonic plague spreads through respiratory droplets during close, sustained contact. It is not the long-range airborne spreader that COVID turned out to be. It does not do silent asymptomatic transmission for a week before anyone feels sick. It announces itself, violently, within a few days.

And it has never been good at sustained human-to-human chains in the modern era. In the United States, we average about seven plague cases a year, mostly in the rural Southwest from fleas and infected animals. Arizona had a fatal pneumonic case in Coconino County in July 2025, written up in MMWR, the county’s first since 2007. The last documented person-to-person transmission of pneumonic plague in the United States was in 1924, in Los Angeles. A century, with the organism present in our own rodents the entire time.

A pathogen that cannot start a chain cannot start a pandemic.

So should you buy N95s?

No.

Not for this. If you already own a box, you did not waste your money, and if you live where I do, wildfire season is a far better argument for keeping them than Irkutsk is. But buying respirators this week as a response to a plague death 5,000 miles away is spending money and worry on the wrong thing.

If you want a useful response to this story, here is one. Know whether you could get a doctor on the phone within 24 hours of getting sick. That is the variable that killed Darya Shipilova, four days of it, and it is the only variable in this entire story that you personally have any control over. The antibiotics work. Getting to them in time is the whole game.

I say that as someone who practices entirely by video, so treat it as the interested opinion that it is.

The Bottom Line

A 28-year-old technician at a Siberian plague institute broke a tube on September 25, went to the hospital on September 29, and was dead within about two days. Russia says there was no accident and no plague while quarantining five medical facilities and tracking 197 contacts. The most likely explanation needs no engineering and no conspiracy: a laboratory exposure that should have been met with seven days of doxycycline within hours, met instead with four days of delay. Plague remains treatable, remains bad at spreading between people, and has not caused person-to-person transmission in this country since 1924. Watch for confirmatory testing and for secondary cases among the contacts. Those are the two things that would change my read. Skip the N95s.

Sources

Hospitals in Irkutsk impose quarantines after an employee at an anti-plague institute dies. Meduza, October 5, 2026. https://meduza.io/en/feature/2026/10/05/hospitals-in-irkutsk-impose-quarantines-after-an-employee-at-an-anti-plague-institute-dies-russia-s-public-health-agency-says-she-died-of-pneumonia-and-the-epidemiological-situation-remains-stable
Nearly 200 People Under Observation After Irkutsk Lab Worker Dies From Plague. The Moscow Times, October 2, 2026. https://www.themoscowtimes.com/2026/10/02/nearly-200-people-under-observation-after-irkutsk-lab-worker-dies-from-plague-a93857
Siberian Anti-Plague Institute Staff Isolated After Worker’s Death. RFE/RL. https://www.rferl.org/a/russia-plague-warning-siberia-irkutsk-laboratory/33870385.html
Plague outbreak in Russia, expert comment by Dr Simon Clarke. University of Reading, 2026. https://www.reading.ac.uk/news/2026/Expert-Comment/Plague-outbreak-in-Russia-expert-comment
Russia plague: What we know about the suspected case reportedly linked to a lab worker’s death. CNBC, October 5, 2026. https://www.cnbc.com/2026/10/05/russia-plague-suspected-case-irkutsk.html
State Department monitoring reported fatal case of pneumonic plague. ABC News, October 2026. https://abcnews.com/US/state-department-monitoring-reported-fatal-case-pneumonic-plague/story?id=136992734
Russian plague lab researcher dies as nearly 200 monitored: here’s what we know. Forbes, October 5, 2026. https://www.forbes.com/sites/siladityaray/2026/10/05/russian-plague-lab-researcher-dies-as-nearly-200-monitored-heres-what-we-know/
Russian lab worker dies of suspected plague in Siberia; US monitoring case. Al Jazeera, October 5, 2026. https://www.aljazeera.com/news/2026/10/5/russian-lab-worker-dies-of-suspected-plague-in-siberia-us-monitoring-case
Has plague returned to Siberia? Panic in Russia after death of lab worker. Euronews, October 4, 2026. https://www.euronews.com/2026/10/04/has-plague-returned-to-siberia-panic-in-russia-after-death-of-lab-worker
The Siberian lab at the centre of a plague scare: its history, work and what it actually does. ThePrint. https://theprint.in/theprint-essential/the-siberian-lab-at-the-centre-of-a-plague-scare-its-history-work-and-what-it-actually-does/3063082/
Recommended antimicrobial pre- and post-exposure prophylaxis for plague. Centers for Disease Control and Prevention, 2021. https://www.cdc.gov/plague/resources/PlagueProphyTreatmentTable_2021-P.pdf
Nelson CA, et al. Antimicrobial Treatment and Prophylaxis of Plague: Recommendations for Naturally Acquired Infections and Bioterrorism Response. MMWR Recomm Rep, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8312557/
Welch TJ, et al. Multiple Antimicrobial Resistance in Plague: An Emerging Public Health Risk. PLoS One, 2007. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1819562/
Notes from the Field: Fatal Pneumonic Plague, Coconino County, Arizona, July 2025. MMWR, volume 75. https://www.cdc.gov/mmwr/volumes/75/wr/mm7538a2.htm
Biopreparat, background on the Soviet biological weapons program. https://en.wikipedia.org/wiki/Biopreparat

Empty bench beside a wet winding path in a foggy leafless forest

2026-2027 Flu Shot: When to Get It, Which One, and Is Tamiflu Worth It?

On September 25, 2026September 25, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Last winter was rough. If you spent a week in January flat on the couch with a fever of 102 and a cough that hung on into February, you had plenty of company, and there is a decent chance the virus that did it was an H3N2 variant called subclade K.

This year’s flu shots are out, and every strain in them has changed. The federal advisory committee that normally tells everyone what to do is also, for practical purposes, not functioning. So I get a lot of the same three questions this time of year, and I am going to answer them here: when should I get it, which one should I get, and if I catch the flu anyway, is Tamiflu worth taking?

What last season looked like

CDC’s preliminary numbers for 2025-2026 are at least 32 million illnesses, 390,000 hospitalizations, and 24,000 deaths from flu (1). The agency classified the season as moderate for adults and high severity for children. By late May, 174 children had died of flu, and about 85 percent of those who were eligible and had a known vaccination status had not been fully vaccinated (1).

Subclade K was the reason. It surfaced in Australia in July 2025, rode the Southern Hemisphere winter north, and by January it accounted for roughly nine of every ten influenza A viruses sequenced in the United States. It had drifted away from the H3N2 strain in last year’s shot.

The shot still did something. CDC’s interim estimate put vaccine effectiveness against flu-related hospitalization at 30 percent in adults and 41 percent in children and teenagers, with outpatient protection at 22 to 34 percent in adults (2). Those are low numbers by flu vaccine standards. Thirty percent sounds unimpressive until you remember the denominator was 390,000 hospitalizations. I will take a 30 percent cut in my odds of being one of them.

What changed in this year’s shot

All three components were updated for 2026-2027, and the H3N2 piece was swapped specifically to cover subclade K (3). FDA’s advisory committee voted on the strains on March 12, 2026. The egg-based vaccines carry an A/Missouri/11/2025 H1N1 strain, an A/Darwin/1454/2025 H3N2 strain, and a B/Victoria strain; the cell-based and recombinant vaccines use closely matched versions (4).

One thing that trips people up at the pharmacy counter. If the pharmacist says they have four different flu shots, that means four types of vaccine, not four strains. Every flu shot in the U.S. this year covers the same three strains. What differs is how the vaccine is made and how strong a response it produces: standard-dose, high-dose (Fluzone High-Dose), adjuvanted (Fluad), recombinant (Flublok), and cell-based (Flucelvax), plus FluMist and the new mRNA shot. Until a couple of years ago most shots were quadrivalent, meaning they covered four strains. One B lineage, B/Yamagata, has not been confirmed anywhere in the world since March 2020, so FDA dropped it, and every U.S. flu vaccine has been trivalent since the 2024-2025 season.

A small aside, because patients ask. Those place names are where the reference virus was collected, not where the strain came from or where it is worst. “Darwin” means a lab in northern Australia isolated the sample that became the template. Nobody should cancel a trip to the Northern Territory over it.

For what it’s worth, Australia’s 2026 winter has been far quieter than 2025’s, which was the deadliest flu season there this century. Their experts are careful to say a mild Southern Hemisphere season does not reliably predict ours (5). I agree with them. I would not plan around it.

Who is actually making the recommendations this year

This part is messy, and I think you deserve a straight account of it.

In 2025, HHS removed the members of the Advisory Committee on Immunization Practices and appointed new ones. On March 16, 2026, a federal judge in Boston stayed those appointments and the votes the reconstituted committee had taken, finding they likely violated federal law (6). That ruling is on appeal. The practical result is that no functioning ACIP has voted on anything for this fall.

CDC’s response, issued September 1, was to state that the flu recommendations from the July 2025 immunization schedule remain in effect for 2026-2027 (7). In plain terms: annual flu vaccination for everyone 6 months and older, the same as it has been for years. On September 2, the American Academy of Family Physicians, the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, and the Infectious Diseases Society of America published their own respiratory-season guidance, and on flu they all say the same thing (8).

Will your insurance cover it? For flu, almost certainly. Medicare Part B covers the flu shot by statute, and AHIP, the trade group for health insurers, has said its members will keep covering the vaccines that were recommended before the committee was replaced. Flu is the one vaccine with decades of annual guidance behind it, so it is the least disrupted of the three fall shots. COVID and RSV are a different and murkier story, and I covered COVID separately.

September or October? My answer depends on your age

CDC’s guidance for most people is September or October (7). I would push that a little depending on who you are.

If you are under 65 and healthy, get it whenever it is convenient between now and the end of October. There is no advantage in waiting, and the most common way people miss their flu shot is by planning to get it “in a few weeks.”

If you are 65 or older, I would aim for October. Protection from the flu shot fades over the season, and it fades faster in older adults, which is why CDC specifically says to avoid July and August vaccination in this group unless there is no other realistic chance to get it (7). Flu in the U.S. usually peaks somewhere between December and February, so a shot in mid-October puts your best protection squarely over those months, while one in early September has already started to fade by the time the worst of it arrives. Do not let “wait for October” turn into “forgot until January,” though. A September shot beats no shot by a wide margin.

Children between 6 months and 8 years who have never had a flu shot, or have had only one dose ever, need two doses four weeks apart. Start those now so the second dose lands before the end of October.

If you are pregnant, you can get the shot in any trimester (7). A shot in the third trimester also protects the baby for the first months of life, before infants are old enough to be vaccinated themselves.

If you are 65 or older, ask for the stronger shot

I encourage everyone to get a flu shot every year, and I push hardest with older adults and anyone medically fragile. Adults 65 and over should preferentially get one of three vaccines: high-dose (Fluzone High-Dose), recombinant (Flublok), or adjuvanted (Fluad) (7). All three produce a stronger immune response than the standard shot in older adults, whose immune systems respond less to a standard dose. Pharmacies stock them. Ask by name.

There is also something new this year. On August 5, 2026, FDA approved mFlusiva, Moderna’s mRNA flu vaccine and the first of its kind, for adults 50 and older (9). In a phase 3 trial of about 40,700 adults, it was about 27 percent more effective than a standard-dose vaccine at preventing PCR-confirmed flu illness. Approval for ages 50 to 64 is standard. For 65 and older it is accelerated approval, which means Moderna still owes FDA a confirmatory study.

I like it. It is what I have chosen for myself this year, and for the members of my family old enough to get it. One fair caveat: the trial compared it against the standard-dose shot, not against high-dose or adjuvanted, so for people over 65 nobody has shown yet that it beats those. For someone 50 to 64 who wants more than the standard shot, it joins Flublok, which is approved for adults of any age, as a good choice. Coverage may lag, because the usual trigger for insurer coverage of a new vaccine is an ACIP vote, and ACIP is not voting.

Honestly, I am fine with whichever version you are comfortable with. The medical groups put it well: take an enhanced vaccine if one is available, but do not delay vaccination hunting for one (8). The best flu shot is the one you actually get.

FluMist, now at home

FluMist, the nasal spray vaccine, is approved for ages 2 through 49. Since last season, AstraZeneca has shipped it directly to homes through its FluMist Home program, and an adult can give it to themselves or to a child in the household (10). Last season it was free with most commercial insurance plus a shipping fee of about $9, and it was not available in every state. I have not been able to confirm this year’s state list, so check the program site before you plan on it.

One catch. It is a live attenuated vaccine, so it is off the table in pregnancy and for people who are significantly immunocompromised or who live with someone severely immunocompromised. For a household of healthy kids who dread needles, it is a genuinely good option.

If you get the flu anyway: the 48-hour window

This is where telemedicine is the right tool for the job.

Flu antivirals work best when started within 48 hours of the first symptom (11). That window closes fast, because a lot of people spend the first day telling themselves it is only a cold and the second day on hold trying to get an appointment somewhere, and by the time they are seen the 48 hours are gone. A video visit collapses that. When flu is circulating in your area, sudden fever, body aches, and a dry cough are enough to diagnose it clinically without a swab, and the prescription goes to your pharmacy the same hour. A home combination COVID and flu test helps if you have one, but it is not required.

When I see someone for flu symptoms by video, the first thing I ask is whether they have had a positive flu test. Then whether they have been around someone they know had the flu recently. And whether they have had a flu shot this year. If the story fits, I prescribe an antiviral.

Now the honest part, about oseltamivir (Tamiflu). For an otherwise healthy adult, the benefit is modest. Real, but modest. The Cochrane review of the drug’s full clinical study reports found it shortened symptoms by about 17 hours, from roughly 7 days to 6.3 (12). A 2024 meta-analysis in JAMA Internal Medicine found no reduction in hospitalization among outpatients treated with oseltamivir, including older and higher-risk patients, and a clear increase in nausea and vomiting (13). CDC and IDSA still recommend treatment for anyone at higher risk of complications, even after 48 hours, and I do treat those patients past the 48-hour mark. The high-risk group includes adults 65 and older, pregnancy, asthma, COPD, diabetes, heart disease, and a BMI of 40 or above.

For a healthy 30-year-old on day one, I think the fair thing is to lay out those numbers and let the patient decide. Some people will gladly take a day off a week of misery. Others would rather skip the nausea. Both reasonable. When an antiviral makes sense, I prescribe either oseltamivir or baloxavir.

Baloxavir (Xofluza) is the other option: a single dose instead of ten pills over five days, approved for ages 5 and up. In the CENTERSTONE trial, published in the New England Journal of Medicine in 2025, a single dose of baloxavir taken within 48 hours cut household transmission of flu from 13.4 percent to 9.5 percent, a 32 percent reduction in the odds of passing it on (14). That is the first antiviral shown to reduce spread. If you live with a newborn, an elderly parent, or someone on chemotherapy, that result matters. Two caveats. CDC does not recommend baloxavir during pregnancy or breastfeeding, and it is often not covered by insurance the way generic oseltamivir is. Some of my patients prefer it anyway, so before I send it to the pharmacy I let them know there may be an out-of-pocket cost.

For patients

Get the shot. If you are under 65, get it now. If you are 65 or older or have serious medical problems, do not skip it; aim for October, and ask about the high-dose, recombinant, adjuvanted, or mRNA versions. If you are between 50 and 64 and want more than the standard shot, ask your pharmacy about Flublok or mFlusiva, and check whether your plan covers the one you pick.

If you get sick, do not wait to see whether it turns into something. Start a video visit on the first day of symptoms. If you are in a higher-risk group, treatment is worth starting even after 48 hours.

Two things mean you should skip the video visit and be seen in person: trouble breathing, or a fever that improves for a day or two and then comes back with a worse cough. That second pattern can be a bacterial pneumonia following the flu. It is the one I worry about most.

For clinicians

Three practical points for this season. First, with no functioning ACIP, standing orders in many systems reference the July 2025 schedule, and CDC’s September 1 interim guidance is the document to cite if anyone asks what authority you are vaccinating under (7). Second, for your patients 65 and older, the preferential-product recommendation still stands, and mFlusiva was compared against standard dose only, so there is no evidence yet that it outperforms Fluad or high-dose in that group. Third, CENTERSTONE gives you a concrete reason to reach for baloxavir when the index patient lives with someone at high risk, provided the patient is 5 or older, not pregnant, and not severely immunocompromised (14).

On oseltamivir for low-risk outpatients, I think shared decision-making is the honest approach, and the Hanula meta-analysis is worth reading before you tell a healthy 30-year-old it will keep them out of the hospital (13). The evidence for that claim in low-risk patients is weak.

The Bottom Line

The 2026-2027 flu shot has been rebuilt around the H3N2 strain that made last winter so hard, and it is covered and available now. Get it by the end of October. If you are 65 or older, the high-dose, recombinant, adjuvanted, and new mRNA shots are all good choices, and October is the sweet spot for timing. Pick the one you are comfortable with and do not delay hunting for a particular brand. And if you do get the flu, the first 48 hours matter. A video visit on day one is the fastest way to use them.

Sources

Centers for Disease Control and Prevention. Weekly US Influenza Surveillance Report: Key Updates for Week 20, ending May 23, 2026. https://www.cdc.gov/fluview/surveillance/2026-week-20.html
Interim Estimates of 2025–26 Seasonal Influenza Vaccine Effectiveness, United States, September 2025–February 2026. MMWR Morb Mortal Wkly Rep. 2026;75(9):116-123. https://pmc.ncbi.nlm.nih.gov/articles/PMC12981535/
Centers for Disease Control and Prevention. 2026-2027 Flu Season. Updated September 2, 2026. https://www.cdc.gov/flu/season/2026-2027.html
U.S. Food and Drug Administration. Influenza Vaccine Composition for the 2026-2027 U.S. Influenza Season. https://www.fda.gov/vaccines-blood-biologics/vaccines/influenza-vaccine-composition-2026-2027-us-influenza-season
Doherty Institute. How severe is this flu season shaping up to be? https://www.doherty.edu.au/articles/how-severe-is-this-flu-season-shaping-up-to-be/
American College of Physicians. Federal Judge Blocks Immunization Schedule Changes, Stays ACIP Member Appointments. March 2026. https://www.acponline.org/acp-newsroom/federal-judge-blocks-immunization-schedule-changes-stays-acip-member-appointments
Centers for Disease Control and Prevention. Interim Clinical Considerations for the Use of Seasonal Influenza Vaccines in the United States. September 1, 2026. https://www.cdc.gov/flu/hcp/vax-summary/seasonal-influenza-vaccines.html
Healthline. U.S. Medical Groups Issue Flu, COVID Vaccine Guidance. September 2026. https://www.healthline.com/health-news/medical-groups-issue-independent-flu-covid-rsv-vaccine-guidance
BioPharma Dive. FDA approves Moderna’s mRNA flu vaccine. August 2026. https://www.biopharmadive.com/news/moderna-fda-approve-mflusiva-seasonal-influenza/826864/
AstraZeneca. FluMist, the nation’s only nasal spray flu vaccine, now available for home delivery. 2025. https://www.astrazeneca-us.com/media/press-releases/2025/FLUMIST-the-nations-only-nasal-spray-flu-vaccine-now-available-for-home-delivery.html
Centers for Disease Control and Prevention. Influenza Antiviral Drug Baloxavir Marboxil. https://www.cdc.gov/flu/treatment/baloxavir-marboxil.html
Jefferson T, Jones MA, Doshi P, et al. Neuraminidase inhibitors for preventing and treating influenza in adults and children. Cochrane Database Syst Rev. 2014;(4):CD008965. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD008965.pub4/full
Hanula R, Bortolussi-Courval É, Mendel A, et al. Evaluation of Oseltamivir Used to Prevent Hospitalization in Outpatients With Influenza: A Systematic Review and Meta-Analysis. JAMA Intern Med. 2024;184(1):18-27. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2805976
Monto AS, Kuhlbusch K, Bernasconi C, et al. Efficacy of Baloxavir Treatment in Preventing Transmission of Influenza. N Engl J Med. 2025;392(16):1582-1593. https://www.nejm.org/doi/full/10.1056/NEJMoa2413156

An amber prescription bottle tipped over on a pale wooden table with pink and white antibiotic capsules spilling out, beside a folded paper card, in bright window light

You Probably Are Not Allergic to Penicillin

On August 31, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

About one in ten Americans carries a penicillin allergy in their chart (1). When those people are actually tested, the large majority are not allergic.

That gap is one of the most consequential unforced errors in medicine, and almost nobody goes back and checks.

Where the label usually comes from

Most penicillin allergy labels were applied in childhood, by someone who is no longer involved, based on something that happened once.

The classic story is a rash during a course of amoxicillin at age four. Here is the problem with that story. Viral illnesses cause rashes. Children with viral illnesses get prescribed antibiotics. When a rash appears on day three, the antibiotic is the thing everyone is looking at, so the antibiotic gets the blame and the label goes in the chart. It never comes out.

The other common origins are a family member’s allergy transferred onto the patient, and side effects filed as allergy. Nausea is not an allergy. Diarrhea is not an allergy. A yeast infection is not an allergy. They are all reasons to dislike a drug and none of them are reasons to avoid it for life.

Even genuine allergy fades. IgE-mediated penicillin sensitivity wanes over time, and a substantial proportion of people who really were allergic at twenty are not allergic at fifty.

The label is not free

This is the part I want to land, because people assume that avoiding penicillin is the cautious choice and therefore the safe one.

It is not. Blumenthal and colleagues followed 64,141 adults carrying a penicillin allergy label against 237,258 matched comparators for a mean of six years (2). The people with the label had an adjusted hazard ratio of 1.69 for MRSA and 1.26 for Clostridioides difficile.

The mechanism is not mysterious, and the authors show it. Those patients received far more of the alternatives: macrolides at over four times the rate, clindamycin at nearly four times, fluoroquinolones at twice (2). Those drugs do more collateral damage to the gut and select harder for resistance. The excess MRSA and C. difficile were mediated by that substitution.

So the label does not sit there harmlessly. It quietly buys worse antibiotics for the rest of a person’s life.

There is a score for this, and it runs on history alone

The thing that changed my thinking here is that you do not need a skin test to identify most of the people who are low risk. You need four questions.

PEN-FAST was derived and validated by Trubiano and colleagues (3). It scores like this:

Five years or fewer since the reaction: 2 points. Anaphylaxis or angioedema, or a severe cutaneous adverse reaction: 2 points. Treatment required for the episode: 1 point.

A score under 3 means low risk. In the derivation cohort, only 17 of 460 low-risk patients tested positive, giving a negative predictive value of 96.3 percent (3).

Read the criteria again and notice what is not in them. No skin prick. No specific IgE. No blood work at all. Every input is something the patient tells you.

That is why this belongs in a conversation rather than a laboratory, and it is why I think most clinicians could be doing more of this than they are.

What I actually do with this on a video visit

I ask everyone about allergies before I prescribe anything. That part is unremarkable. What is worth describing is what happens next, because it is where most of these labels give themselves away.

When somebody tells me they are allergic to amoxicillin, I ask what the reaction was.

Two answers come back more than any others. The first is that they do not really remember, because they were a baby and their parents told them. The second is some version of “I think I am allergic because my mom is.”

Neither of those is an allergy history. The second one is not even about the patient.

Here is where I part company with the enthusiastic version of this argument. A person who is sick today and needs an antibiotic today is not in a good position to test a theory about their own immune system. If there is any real concern about anaphylaxis in what I am hearing, I do not push it. I pick something else and move on, and I am comfortable with that.

I also do not send people off for an oral challenge as a matter of course. That is a real procedure with a real indication, and routing every vague childhood label into an allergy clinic is not a good use of anyone’s afternoon.

What I do instead is tell them the label is worth reopening properly, and that the time to do it is when they are well rather than in the middle of an infection. It belongs with whoever manages their ongoing care, in a visit where nobody is waiting on a prescription.

The distinction matters. The label deserves to be examined. The examination should not happen while someone is sick and I am trying to treat them.

What a real reaction looks like, and what has changed about treating it

None of the above applies to someone who has had a genuine severe reaction. Anaphylaxis, angioedema, or a severe cutaneous adverse reaction such as Stevens-Johnson syndrome or DRESS means the label stays. Those people are not candidates for de-labeling and should not be challenged.

Worth knowing what has changed on the treatment side. For decades the only option for anaphylaxis outside hospital was an intramuscular auto-injector. There is now an FDA-approved epinephrine nasal spray, neffy, the first intranasal adrenaline product to reach the market (4). Pharmacokinetic studies show plasma concentrations comparable to or exceeding intramuscular injection, and, counterintuitively, nasal congestion does not appear to impair absorption (5).

I mention it because needle avoidance is a real reason people leave their epinephrine at home, and a device you will actually carry beats a better device you will not. If someone genuinely needs to carry epinephrine and the needle is the barrier, that conversation is now worth having.

It does not change the rule that epinephrine is the treatment and antihistamines are not.

For patients

If your penicillin allergy dates from childhood and you cannot remember what happened, it is worth reopening. Ask specifically to be assessed rather than mentioning it in passing, because in passing it stays in the chart.

Before that conversation, work out three things: roughly when it happened, what you or your parents remember seeing, and whether anyone treated it. That is most of the assessment.

Raise it when you are well. A visit for an infection is the wrong moment, because whoever is treating you needs to choose an antibiotic today and will reasonably play it safe. Bring it to a routine appointment instead, when nobody is waiting on a prescription.

If you have taken amoxicillin, Augmentin or any similar antibiotic since the original reaction and were fine, say so early. It is the single most useful thing you can tell your clinician.

And if your reaction involved breathing trouble, swelling of the face or throat, or a blistering rash, the label is real and it stays.

For colleagues

PEN-FAST costs four questions and identifies low-risk labels at the point of care with a negative predictive value of 96.3 percent (3). We are not short of the tool. We are short of anyone taking ownership of the conversation.

Frame it as a safety intervention rather than a convenience one, because it is. The hazard ratios in the Blumenthal cohort are for MRSA and C. difficile, not for inconvenience (2).

And ask the question that costs nothing: has this person taken a penicillin since. A meaningful share of these labels fall over on that answer alone.

The Bottom Line

Roughly ten percent of people carry a penicillin allergy label and most of them are not allergic, usually because a childhood viral rash got blamed on an antibiotic. The label is not harmless. Carrying it is associated with a 69 percent higher risk of MRSA and a 26 percent higher risk of C. difficile, driven by the broader antibiotics used instead. Four questions, scored as PEN-FAST, identify most low-risk labels without any testing at all, which makes this one of the few things in medicine that is fixed by a conversation. If your reaction was anaphylaxis, angioedema or a blistering rash, the label stays and you keep your epinephrine, which now comes as a nasal spray as well as an injector.

Sources

1. Shenoy ES, Macy E, Rowe T, Blumenthal KG. Evaluation and management of penicillin allergy: a review. JAMA. 2019;321(2):188-199. PMID 30644987. https://pubmed.ncbi.nlm.nih.gov/30644987/

2. Blumenthal KG, Lu N, Zhang Y, Li Y, Walensky RP, Choi HK. Risk of meticillin resistant Staphylococcus aureus and Clostridium difficile in patients with a documented penicillin allergy: population based matched cohort study. BMJ. 2018;361:k2400. PMID 29950489. https://pubmed.ncbi.nlm.nih.gov/29950489/

3. Trubiano JA, Vogrin S, Chua KYL, et al. Development and validation of a penicillin allergy clinical decision rule. JAMA Intern Med. 2020;180(5):745-752. PMID 32176248. https://pubmed.ncbi.nlm.nih.gov/32176248/

4. Hernandez-Trujillo V, Tachdjian R, et al. Successful administration of neffy (epinephrine nasal spray) by patients and caregivers. Ann Allergy Asthma Immunol. 2026. PMID 42476303. https://pubmed.ncbi.nlm.nih.gov/42476303/

5. Takahashi K, Yanagida N. Intranasal adrenaline: a new treatment for anaphylaxis. Pediatr Allergy Immunol. 2026;37(3):e70316. PMID 41796069. https://pubmed.ncbi.nlm.nih.gov/41796069/

Two empty medical vials and syringe beside an illustrated human brain

Does the Shingles Vaccine Lower Dementia Risk? What the Evidence Shows

On August 30, 2026August 31, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

I wrote about shingles here in 2012. Back then the vaccine question was simple and slightly boring: there was one shot, it worked reasonably well, and most people over 60 were told to consider it.

The question I get now is different. People do not ask me whether the shingles vaccine prevents shingles. They ask whether it protects the brain.

That is a fair question, the evidence behind it is more interesting than most vaccine headlines, and it has a catch in it that almost nobody reporting on it mentions.

Start with the boring part, because it is the part that matters

Shingles is the chickenpox virus waking up. It sat in a nerve root for decades and then came back out along that nerve, which is why the rash arrives in a band on one side and stops at the midline.

The rash heals. The nerve pain is the problem. Postherpetic neuralgia is burning, electric pain in the same distribution that can outlast the rash by months, occasionally years, and it is genuinely difficult to treat once it settles in. That, not the rash, is the reason to care about this.

The current vaccine is Shingrix, given as two doses. In the ZOE-50 trial across more than 15,000 adults aged 50 and over, efficacy against shingles was 97.2 percent (1). In ZOE-70, in adults 70 and older, it was 89.8 percent, and in the pooled analysis of everyone over 70 across both trials, efficacy against postherpetic neuralgia specifically was 88.8 percent (2).

Those are very good numbers. Vaccines rarely perform like that in the age group where you most want them to work.

It is a reactogenic shot. Roughly one in six people feels properly unwell for a day or two after a dose, sore arm, tired, achy, sometimes feverish. I tell people that in advance, because a person who was warned takes the second dose and a person who was ambushed does not.

The dementia finding, and the catch

Here is where it gets interesting.

In 2025, a group at Stanford published a study in Nature that used an accident of Welsh policy (3). When Wales rolled out the shingles vaccine, eligibility was set by exact date of birth. Anyone born before 2 September 1933 was ineligible, permanently. Anyone born on or after that date was eligible.

Think about what that creates. A person born on 1 September 1933 and a person born on 3 September 1933 are, on average, identical in every way that matters. Same generation, same health, same everything. The only systematic difference between them is that one could get the vaccine and one could not. Uptake went from 0.01 percent in the group one week too old to 47.2 percent in the group one week younger.

That is as close to a randomized trial as you will ever get out of routine health records without running one.

Over seven years, the vaccinated group had a 3.5 percentage point lower probability of a new dementia diagnosis, which works out to a 20 percent relative reduction (3). The effect was stronger in women. The authors then reproduced it in a separate population using death certificates rather than diagnoses, which guards against the finding being an artifact of who happens to get diagnosed.

Now the catch.

Wales was using Zostavax, the old live-attenuated vaccine. That product was withdrawn from the US market in November 2020. It is not what you would be offered today, and the study does not tell you what Shingrix does.

A separate group looked at exactly that, using the rapid switchover from live to recombinant vaccine as its own natural experiment, and found the recombinant vaccine associated with a 17 percent increase in dementia-free time, about 164 extra days without a diagnosis among those who went on to be diagnosed, over six years (4). Again larger in women. I will note, because they note it, that the senior author consults for the manufacturer, and that GSK had no involvement in the study and did not know about it until after acceptance.

What I actually think about it

I think the signal is real and I do not think it should be the reason you get the shot.

Those are compatible positions. The dementia work is observational in design even when it is cleverly built, the mechanism is unproven, and no randomized trial has tested it. Something could still be wrong with it. Meanwhile the case for Shingrix rests on two large randomized controlled trials showing it prevents a disease that causes months of nerve pain, and that case was already sufficient on its own.

So my framing is this. Get it because postherpetic neuralgia is miserable and largely preventable. If the dementia finding holds up, you will have gotten that for free.

What the finding does change is urgency. I used to be relaxed when someone in their early fifties wanted to put it off a few years. I am less relaxed now, because if there is a neurological benefit it presumably accrues with time, and there is no advantage to waiting.

The part that belongs to my day job

Most of my practice is metabolic, and shingles turns out to sit closer to that than it looks.

A meta-analysis of sixteen studies put the risk of shingles in people with diabetes at a pooled relative risk of 1.38 compared with the general population (5). A separate population cohort found that people with diabetes had roughly 1.45 times the risk of postherpetic neuralgia, and that when they got it, it tended to be more severe and more persistent (6).

So the group most likely to get shingles, and most likely to be left with lasting nerve pain afterward, overlaps heavily with the group I see for weight and glucose.

There is a second reason this matters in diabetes that has nothing to do with the vaccine. Postherpetic neuralgia and diabetic peripheral neuropathy feel similar, they get treated with the same drugs, and I have seen the second diagnosis absorb the first. If burning pain shows up in a band, on one side, in a person who also has stocking-glove neuropathy, that is shingles until proven otherwise, whatever the chart already says.

Age 50 is also, not coincidentally, right in the middle of the menopause transition, which is the other half of what I do. If a woman is already in front of me talking about hormone therapy and bone density, the shingles vaccine is a reasonable thing to raise in the same visit, and often nobody has.

If you already have it, the clock is the thing

Antivirals for shingles work best started within 72 hours of the rash appearing. After that the benefit falls off steeply.

That single fact is the strongest argument I know for handling suspected shingles by video. A one-sided painful band of blistering rash with a burning prodrome is one of the more recognizable things in medicine, and a decent photograph plus a history usually settles it. The bottleneck has never been diagnostic difficulty. It has been how long it takes to be seen, and a visit you can get this afternoon beats a better visit on Thursday.

Two exceptions I do not manage remotely. A rash near or in the eye, particularly on the tip of the nose, needs same-day ophthalmology because of the risk to the cornea. Shingles in someone significantly immunocompromised, or a disseminated rash crossing the midline, goes in person.

For patients

If you are 50 or over, you are eligible for Shingrix regardless of whether you remember having chickenpox, and regardless of whether you had the old vaccine years ago.

If you are immunocompromised, the recommendation starts at 19 (7).

Expect to feel rough for a day after each dose, and get the second one anyway. One dose is not the regimen.

If a painful one-sided rash appears, get seen inside three days. Do not wait to see whether it spreads.

For colleagues

The dementia data is worth knowing and worth describing accurately. The strongest causal design was done on a product no longer sold in the United States, and patients who have read a headline usually have not been told that.

Diabetes belongs on the list of reasons to push the vaccine actively rather than mention it in passing.

And check the vaccine history of the metabolic patients. Nobody owns this conversation, so it tends not to happen. I have started treating it as part of the same visit rather than something to refer out, and it costs about ninety seconds.

The Bottom Line

Shingrix prevents shingles about 97 percent of the time in adults over 50, and it prevents postherpetic neuralgia, which is the thing actually worth avoiding. A natural experiment in Wales found 20 percent less dementia over seven years in vaccinated adults, and a second study suggests the current recombinant vaccine carries a similar signal, but the strongest of that evidence came from a live vaccine the United States no longer uses. Get the vaccine for the nerve pain it reliably prevents rather than the dementia it might. If you have diabetes, your risk of both shingles and lasting nerve pain afterward is meaningfully higher, which moves this up the list. And if a one-sided painful rash turns up, the antiviral window is 72 hours.

Sources

1. Lal H, Cunningham AL, Godeaux O, et al. Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med. 2015;372(22):2087-2096. PMID 25916341. https://pubmed.ncbi.nlm.nih.gov/25916341/

2. Cunningham AL, Lal H, Kovac M, et al. Efficacy of the herpes zoster subunit vaccine in adults 70 years of age or older. N Engl J Med. 2016;375(11):1019-1032. PMID 27626517. https://pubmed.ncbi.nlm.nih.gov/27626517/

3. Eyting M, Xie M, Michalik F, et al. A natural experiment on the effect of herpes zoster vaccination on dementia. Nature. 2025;641(8062):438-446. PMID 40175543. https://pubmed.ncbi.nlm.nih.gov/40175543/

4. Taquet M, Dercon Q, Todd JA, Harrison PJ. The recombinant shingles vaccine is associated with lower risk of dementia. Nat Med. 2024;30(10):2777-2781. PMID 39053634. https://pubmed.ncbi.nlm.nih.gov/39053634/

5. Huang CT, Lee CY, Sung HY, et al. Association between diabetes mellitus and the risk of herpes zoster: a systematic review and meta-analysis. J Clin Endocrinol Metab. 2022;107(2):586-597. PMID 34536279. https://pubmed.ncbi.nlm.nih.gov/34536279/

6. Wen SY, Ou-Yang C, Hsu CY, et al. Impact of type 1 versus type 2 diabetes on developing herpes zoster and post-herpetic neuralgia: a population-based cohort study. Acta Derm Venereol. 2023;103:adv9400. PMID 37787418. https://pubmed.ncbi.nlm.nih.gov/37787418/

7. Anderson TC, Masters NB, Guo A, et al. Use of recombinant zoster vaccine in immunocompromised adults aged 19 years and older: recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2022;71(3):80-84. PMID 35051134. https://pubmed.ncbi.nlm.nih.gov/35051134/

A stack of folded white cotton bed linens beside a plain tube of cream and a glass of water on a sunlit wooden nightstand

Why Am I Still Itching After Scabies Treatment?

On August 29, 2026September 11, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

The scabies post I wrote in 2012 gets read more than anything else on this site, which still surprises me. And the question that comes back from it is almost always the same one. I did the treatment. Why am I still itching?

There are two very different answers, and telling them apart is the whole job.

Itching is not the same as infestation

Scabies itch is an allergic response. The mite burrows, and your immune system reacts to the mite, its eggs and its waste. Kill every mite tonight and all of that material is still sitting in your skin tomorrow, and your immune system is still reacting to it.

So the itch outlasts the infestation. Reliably. Two to four weeks is ordinary and six is not rare, and during that time you can be completely mite-free and completely miserable.

This is the single most useful thing to know about scabies, and almost nobody is told it at the pharmacy counter. People finish the cream, itch for another two weeks, conclude it failed, and go looking for a second prescription they may not need.

How to tell persistent itch from actual failure

The direction of travel matters more than the intensity.

Post-treatment itch gets slowly better. Some days are worse, but the trend over a fortnight runs downward, no new spots appear, and the places that itched worst at the start are the places that quiet down first, which is what you would expect if what is happening is an immune reaction winding itself down rather than an infestation carrying on.

Failure looks different. New burrows, fresh papules in places that were clear, itch that is escalating rather than settling, and household contacts starting to scratch two weeks after you did.

Burrows settle it. Thin, slightly raised, greyish lines a few millimetres long, most often in the finger webs, the wrists, the belt line, around the nipples, and on the genitals. New burrows mean live mites.

Timing helps too. An itch that was improving and then turned around at week three is reinfestation or failure. The tail of the original reaction does not do that.

Failure is more common than people think

A systematic review and meta-analysis in the British Journal of Dermatology pooled 147 studies and put the overall treatment failure rate at 15.2 percent (1). Not a rounding error. Roughly one in seven.

By drug, permethrin failed 10.8 percent of the time, oral ivermectin 11.8 percent and topical ivermectin 9.3 percent (1).

Two numbers from that paper changed how I think about this. The first is dosing: a single dose of oral ivermectin failed 15.2 percent of the time against 7.1 percent for two doses (1). Ivermectin does not kill eggs. One dose leaves the next generation to hatch, which is why the second dose at day eight to fourteen is not optional.

The second is the trend. Across studies from 1983 to 2021, overall failure rose by 0.27 percent per year, and permethrin failure by 0.58 percent per year (1). The authors are careful to say that no study in the review actually assessed resistance, so this is a signal and not a finding. But permethrin is working less well than it used to, and if your treatment failed, that is a real possibility rather than a personal failing.

The boring reasons treatment fails

Usually the reason is application.

Neck down, every square inch. People miss the same places every time: between the toes, under the fingernails and toenails, the navel, the buttock crease, behind the ears. In infants, the elderly and anyone immunosuppressed, the scalp and face need treating too, which contradicts the neck-down instruction most people are given.

Leave it on eight to fourteen hours. Wash hands after applying and it comes straight back off, so reapply to the hands after any handwashing.

Treat everyone in the household on the same day, symptoms or not. Someone incubating quietly will hand it back to you in three weeks.

Repeat at day seven. The cream does not reliably kill eggs either, which is the same problem ivermectin has and the same reason the second application exists.

On the laundry, I am less strict than most instructions you will read. Classic scabies transmits by prolonged skin-to-skin contact, and fomite transmission is minor outside crusted scabies. Bedding, towels and clothing from the last three days, hot wash or bagged for three days, is enough. Nobody needs to shampoo a mattress.

The lumps that stay for months

Nodular scabies is worth naming because it frightens people. Firm, itchy, reddish-brown nodules on the scrotum, groin or armpits. They can persist for weeks to months after successful treatment. They are a granulomatous immune response, not live infestation, and treating them again with a scabicide does nothing. They respond to a topical steroid and to time.

When the itch is not scabies at all

Here is where I want to be direct, because this is the failure mode I care most about.

If you were treated for scabies, you never had burrows, no household contact ever itched, and you are still itching at eight weeks, the working diagnosis was probably wrong.

Generalized itch with no primary rash is its own clinical problem, and the list behind it is largely internal. Dry skin and eczema account for most of it. But persistent itch without a rash is also how uncontrolled diabetes, chronic kidney disease, cholestatic liver disease, thyroid disease, iron deficiency and some blood disorders present. In a patient with unexplained itch and no burrows, I would rather check an A1c, a metabolic panel, liver function, thyroid and a CBC than write a third prescription for permethrin.

That scenario is not rare. It is the one that gets missed while everyone concentrates on the mite.

What I ask for on a video visit

Two photographs. One from a distance showing the distribution, which is diagnostic in itself, and one macro shot as close as the phone will focus, aimed at a finger web or a wrist. Back up six inches if it will not focus, which fixes it nearly every time.

I ask when the itch is worst, because scabies is classically worse at night, and I ask who else in the house is scratching. The household answer is often better evidence than the photographs.

For patients

Itching for two to four weeks after correct treatment is expected and does not mean it failed. Watch the direction, not the intensity.

If you were given a single dose of oral ivermectin and nothing else, ask about the second dose. If new spots or new burrows appear, go back. And if you have been itching for two months with nothing to see on the skin, ask for blood work rather than another cream.

For colleagues

The two-dose ivermectin regimen has the evidence behind it and single-dose prescriptions are still going out. That is the cheapest fix available in this whole area.

Tell people at the point of prescribing that the itch will outlast the mite. It prevents a second visit, a second prescription and a great deal of anxiety, and it takes about ten seconds.

And keep systemic pruritus on the list. A patient on their third scabicide with no burrows and no contacts deserves labs, not a refill.

The Bottom Line

Itch that is slowly improving two to four weeks after treatment is the immune system finishing its argument with a mite that is already dead. Itch that is escalating, or that comes with new burrows or newly scratching housemates, is failure or reinfestation, and failure runs around one in seven. If you got one dose of ivermectin, you got half a treatment. And if the itch has gone on for months with nothing visible on the skin, the problem may never have been on your skin at all.

Sources

1. Mbuagbaw L, Sadeghirad B, Morgan RL, et al. Failure of scabies treatment: a systematic review and meta-analysis. Br J Dermatol. 2024;190(2):163-173. PMID 37625798. https://pubmed.ncbi.nlm.nih.gov/37625798/

2. DermNet. Scabies. https://dermnetnz.org/topics/scabies

Round beige adhesive bandage on an adult's upper arm after a vaccination

2026-2027 COVID Vaccine: Who Qualifies, and Do You Need a Doctor’s Note?

On August 28, 2026September 11, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

The updated COVID-19 shots were approved on August 27 and 28, 2026, and they started shipping the same week. If you went looking for one last fall and got turned around at the pharmacy counter, or told to come back with something in writing from your physician, this post is mostly for you.

Here is what is out, who can get it, what counts as high risk, and what the virus is doing right now.

What was approved, and when you can actually get it

FDA cleared XFG-adapted formulas from all three manufacturers. Pfizer-BioNTech’s Comirnaty was approved August 27 (1). Moderna’s Spikevax and mNexspike followed (2). Novavax announced its Nuvaxovid approval on August 28, alongside clearances in the EU and Japan (3). XFG is a recombinant in the JN.1 family, and it replaces last season’s LP.8.1 formula (4).

Now the part I get asked about most, and the part I cannot give you: there is no state-by-state rollout calendar. No health department publishes a date on which residents of that state become eligible, because distribution is commercial rather than federally allocated. Manufacturers ship to distributors, distributors ship to chains and clinics, and stock arrives store by store over days to a few weeks. Your pharmacy may have doses Tuesday while the one four miles down the road is waiting on Thursday’s truck.

So do not wait for an announcement. Set an alert on your pharmacy’s scheduling page, or call and ask when their first shipment lands.

Where the virus is right now

I want to be careful here, because the headlines and the data are telling slightly different stories.

CDC’s wastewater program is the most reliable read we have. For the week ending August 22, 2026, the national wastewater viral activity level for SARS-CoV-2 was 2.14, which CDC classifies as Very Low (5). That same number sat at 1.00 through most of July. It has roughly doubled in six weeks while staying inside the lowest category. So yes, transmission is climbing on the usual back-to-school schedule. No, we are not in a surge yet.

The regional picture is lopsided. The South is currently the highest region at 3.34. Texas is the real outlier at 11.76 across 40 reporting sites, the only state sitting in the Very High band. Mississippi reads 8.92 and South Carolina 7.47, but both are flagged for limited coverage, with two and three reporting sites respectively, so treat those as a signal rather than a measurement. Hawaii is at 7.26 across ten sites. Then Nevada 6.01, California 5.87 across 79 sites, West Virginia 5.61, Louisiana 5.31, and Florida 5.30 (6).

The variant names have shuffled again. Over the four weeks ending August 1, 2026, the two most common in CDC’s sequencing were SW.2 at about 21 percent and XFG.1.1 at about 16 percent (7). XFG.1.1 belongs to a family. Count its close relatives together and the XFG group accounts for roughly 35 percent of what is going around, which is why FDA picked XFG as this year’s vaccine target. NB.1.8.1, the one the press nicknamed Nimbus last summer, has faded to about 4 percent. BA.3.2 sits near 2 percent.

Here is the caveat, and most coverage skips it. Those percentages rest on a very small number of samples. CDC flags all eighteen of the lineages it reported for that period as based on fewer than ten sequenced specimens, or unreliable for other statistical reasons (7). In February the agency could name more than two hundred lineages circulating in the country. This month it could name eighteen. Genetic sequencing of the virus has dropped off sharply, so the variant list is a rough sketch rather than a headcount.

Which is why I put more weight on the wastewater curve than on the variant percentages right now. Genomics tells you the flavor. Wastewater tells you the size.

The page to bookmark

CDC posts wastewater viral activity by state here, and it is updated every Friday with the previous week’s numbers:

https://www.cdc.gov/wastewater/respiratory-viruses/state.html

It covers influenza A, SARS-CoV-2 b (Covid-19), and RSV on the same page, so you can see which of the three is actually moving in your area before you decide whether that sore throat needs a test. If you want the county-level view alongside emergency department visit data, CDC’s Respiratory Illnesses Data Channel has a search box for your state or county:

https://www.cdc.gov/respiratory-viruses/data/index.html

Bookmark the first one. It answers the question patients are really asking, which is not “how bad is COVID nationally” but “is there anything going around here.”

Who the FDA says can get it

The licensed indications are narrower than they were before 2025, and they differ slightly by product:

Comirnaty (Pfizer-BioNTech), mRNA: ages 65 and older, or ages 5 through 64 with at least one condition that raises the risk of severe COVID-19 (1)
Spikevax (Moderna), mRNA: ages 65 and older, or 6 months through 64 with at least one such condition (2)
mNexspike (Moderna), mRNA: ages 65 and older, or 12 through 64 with at least one such condition (2)
Nuvaxovid (Novavax), protein-based rather than mRNA: ages 65 and older, or 12 through 64 with at least one such condition (3)

CDC’s own recommendation, unchanged since the September 2025 ACIP vote, covers everyone 6 months and older under individual-based decision-making (8). So the federal recommendation is broader than the federal license. That gap is exactly where the confusion at the pharmacy counter lives, and nobody at either agency has resolved it for you.

The high-risk list is longer than you think

Most people badly underestimate how wide this list is. CDC’s conditions, in alphabetical order rather than order of risk: cancer, cerebrovascular disease, chronic kidney disease at any stage, chronic liver disease, chronic lung disease including asthma, cystic fibrosis, dementia and other neurologic conditions, type 1 or type 2 diabetes, disabilities, heart conditions, hemoglobin blood disorders, HIV, an immunocompromising condition, mental health conditions, overweight and obesity, physical inactivity, pregnancy, current or former smoking, solid organ or stem cell transplant, substance use disorders, and tuberculosis (9).

Read the back half of that again. Overweight is defined as a BMI of 25 or higher (9). About 72 percent of American adults age 20 and over fall at or above that line, combining the 31.7 percent who are overweight with the 40.3 percent who have obesity (10). Current smoking counts, and so does former smoking. So does physical inactivity. So does depression.

Here is my opinion, and I hold it firmly. A criteria list that broad is not functioning as a clinical gate. It is functioning as paperwork. If you are an adult in the United States, the odds are strong that you already qualify under a criterion you would not have thought to claim, and the honest thing for the system to do would be to say so out loud instead of making each person audit themselves at a kiosk.

Do you need a note from your doctor?

Short answer: almost certainly not, and you should not assume you do.

On September 19, 2025, ACIP voted to recommend COVID-19 vaccination for everyone 6 months and older through individual-based decision-making. In the same meeting it took up a proposal that would have let jurisdictions require a prescription, and that proposal failed on a tiebreaker cast by the committee chair (8, 11). CDC’s position is that the required conversation can happen with a pharmacist, a nurse practitioner, or a PA standing right there at the counter. No written order from your physician.

What tripped people up last fall was state law rather than federal policy. Several states had written pharmacist vaccination authority so that it tracked ACIP’s recommendation language directly, and when that language narrowed, pharmacists in those states abruptly lost standing authority to vaccinate without a prescription. By late September 2025, 26 states had issued standing orders or executive actions restoring broader access (12). The rest had not, and store-level policy varied inside states that had.

Two phone calls save you an afternoon. Call the pharmacy, ask whether they need a prescription for someone your age and situation, and ask whether the 2026-2027 formula is physically on their shelf yet. Then call the number on the back of your insurance card and ask what your plan covers this season. Your state health department’s immunization page is worth two minutes as well, since that is where a new standing order would appear first.

And if a pharmacy does turn you away for want of an order, that is a five-minute problem for your physician to solve, not a reason to abandon the shot. Call the office. Do not walk out and let it go until spring.

Why I think the restrictions backfire

Because the numbers are already bad, and friction is the best explanation for them.

Only 17.5 percent of American adults received the 2025-2026 COVID vaccine, measured at the close of the season in February 2026 across a survey sample of roughly 197,000 people (13). Among adults 65 and older, the group with the clearest, least-debatable benefit, coverage reached 33.5 percent (13). Two-thirds of the highest-risk group in the country did not get vaccinated.

I do not believe most of that gap is ideological. Some of it is. Most of it is drag. Every additional step you insert between a mildly willing person and a needle removes some of them, and the removal is silent. An eligibility attestation form removes a few. A phone call to confirm the pharmacy will actually do it removes a few more. An uncertain bill removes more still. None of those people write a letter explaining why they gave up. They just do not come.

There is a second cost that gets less attention. When the government tells healthy adults they no longer qualify, the message the public hears is that the shot is not worth much. That message does not stay inside its intended audience. It reaches the 68-year-old with COPD who did qualify, who now assumes the whole thing has been downgraded, and who skips it.

If you decided back in 2021 or 2022 that two doses were enough and you have not thought about it since, I would ask you to reconsider on narrow, unromantic grounds. Not because the pandemic is back. Because protection fades, this year’s formula is matched to what is circulating now, and the downside of a sore arm for two days is very small next to a week of illness you did not need to have.

Has the virus changed?

Not in the way people fear. Severity has not meaningfully increased. WHO and ECDC have continued to rate the currently circulating variants as low risk for severe outcomes, and the mutations driving the current lineages are the immune-evasion kind rather than the tissue-damage kind. Laboratory work on XFG published in 2025 found roughly a two-fold drop in neutralizing antibody effectiveness compared with the then-dominant lineage, which explains reinfection without implying worse disease (14).

Symptoms are the familiar Omicron picture. Sore throat, often genuinely severe. Hoarseness. Congestion, cough, fatigue, headache, body aches, and sometimes nausea or loose stools. Loss of smell is far less common than it was in 2020. The “razor blade throat” description that attached itself to NB.1.8.1 in 2025 has stuck around in press coverage, and it is a real complaint, though it is also just a bad Omicron sore throat rather than a diagnostic sign.

What to monitor: shortness of breath at rest or on minimal exertion, chest pain, confusion or unusual difficulty staying awake, bluish lips, and an inability to keep fluids down. Watch for the pattern where someone improves for several days and then clearly worsens around day seven to ten. If you own a fingertip pulse oximeter, a resting reading that keeps coming back at 94 percent or below deserves a same-day call, not a wait-and-see.

Treatment still exists and is still underused. Nirmatrelvir-ritonavir has to be started within five days of symptom onset in adults at high risk of progression, which as we established covers a very large share of adults (15). Day six is too late. If you are in a risk category, know before you are sick how you would reach a clinician quickly.

How long do you stay home?

CDC no longer has a five-day isolation rule, and has not since 2024. The current guidance is symptom-based. Stay home and away from others while you are sick. You can return to normal activities once both of the following have been true for at least 24 hours: your symptoms are improving overall, and you have had no fever without using fever-reducing medication (16).

Then take added precautions for the next five days. Mask well, keep some distance, improve ventilation, and test before you spend time around anyone vulnerable. If a fever returns or you get worse after going back out, go home again and restart the same clock (16).

On work: CDC does not recommend a fixed number of days off, and there is no federal number for your employer to enforce. Your workplace policy is its own creature, and so is your child’s school district. If HR asks for a return-to-work note, that is a workplace requirement rather than a public health one, and it is worth saying so plainly when you ask your physician for it. Healthcare workers and staff in long-term care facilities are the exception and should follow their facility’s occupational health rules instead.

What else lowers your risk

The vaccine is the biggest lever. Metabolic health is the second one, and it is the one you have some control over between now and January.

CDC’s own analysis of 148,494 adults treated at 238 US hospitals found risk of COVID-19 hospitalization was lowest at a BMI of 24.2, ICU admission lowest at 25.9, and death lowest at 23.7, with risk climbing sharply above those points (17). That is a dose-response curve, not a threshold effect, which means movement in the right direction counts even if you do not reach a target number.

Two other findings are worth putting side by side, because together they say something more useful than either does alone.

In a Scottish study of 3.6 million people, vaccinated adults with a BMI over 40 were 76 percent more likely to be hospitalized or die from COVID-19 than vaccinated adults at a normal BMI (adjusted rate ratio 1.76, 95% CI 1.60 to 1.94). In the prospective arm of the same work, 55 percent of people with severe obesity had unquantifiable neutralizing antibody titers six months after their second dose, compared with 12 percent of people at a normal BMI. A third dose restored neutralizing capacity, and then it declined faster again (18).

Meanwhile, in a cohort of 9.17 million adults in England, protection against hospitalization two weeks after the second dose was essentially identical across BMI categories, with an odds ratio of 0.32 in people with obesity against 0.34 in people at a healthy weight. Protection against death was actually stronger in the obesity group, 0.26 against 0.39 (19).

Put those together and the conclusion is not the one people expect. The vaccine works in people with obesity. Its protection simply fades faster. That is an argument for getting the seasonal dose rather than skipping it, and it is the single clearest reason I push seasonal vaccination hardest in my obesity medicine patients.

If you are working on weight for metabolic reasons, this belongs on the list of reasons alongside the ones you already know. I have written about the current medication options in New Weight Loss Pills Foundayo and Wegovy Explained, and about what sustains loss over years in Doctor Supervised Weight Loss: What Works Long Term. For the version of this discussion from last season, including how the eligibility fight started, see.

Two smaller things. You can get the COVID vaccine and the flu vaccine at the same visit, one in each arm, and doing so is the single easiest way to make sure both actually happen (20). And CDC’s risk list includes physical inactivity as its own line item, which is a quiet reminder that the walk you keep meaning to start is doing more than one job.

For patients

Check the wastewater page for your state before you decide how careful to be this month. Call your pharmacy, ask about stock and about whether they need a prescription where you live, and book the appointment while you are on the phone. If you are 65 or older, or you have any condition on that list, do not let a form at the counter end the attempt. If you have been waiting since your first two doses in 2021, this is a reasonable year to restart.

For colleagues

Three practical notes. First, expect the FDA-license-versus-CDC-recommendation gap to generate pharmacy callbacks again this fall, and consider building a standing message your staff can send rather than routing each one to you. Second, screen for eligibility criteria your patients will not volunteer: former smoking status, physical inactivity, and a documented mental health condition all qualify under the CDC list and are all commonly missing from problem lists. Third, if you practice by video as I do, the eligibility conversation is straightforward to complete in a visit that is already happening for something else, and it takes about ninety seconds.

The Bottom Line

The 2026-2027 vaccines are approved, matched to XFG, and shipping now. There is no statewide rollout date to wait for, so call your pharmacy. You very likely qualify under criteria broader than you assume, and you almost certainly do not need a note from me or anyone else, though it is worth one phone call to confirm before you drive over. COVID activity is low nationally and rising, with Texas and the South well ahead of everyone else. And if you stopped after your first two doses because the emergency ended, the case for one more is quiet and practical rather than dramatic: your protection has faded, this formula matches what is going around, and the shot is easier to get than the illness is to sit through.

Sources

Pfizer and BioNTech Receive U.S. FDA Approval for XFG-adapted COVID-19 Vaccine. August 27, 2026. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-receive-us-fda-approval-xfg-adapted
Moderna Receives U.S. FDA Approval for Updated 2026-2027 COVID-19 Vaccines. August 2026. https://www.biospace.com/press-releases/moderna-receives-u-s-fda-approval-for-updated-2026-2027-covid-19-vaccines
Novavax’s Partnership Strategy Continues to Deliver with XFG-adapted Nuvaxovid Approvals in the U.S., EU and Japan for the 2026-2027 Vaccination Season. August 28, 2026. https://www.biospace.com/press-releases/novavaxs-partnership-strategy-continues-to-deliver-with-xfg-adapted-nuvaxovid-approvals-in-the-u-s-eu-and-japan-for-2026-2027-vaccination-season
U.S. Food and Drug Administration. COVID-19 Vaccines (2026-2027 Formula) for Use in the United States Beginning in Fall 2026. https://www.fda.gov/vaccines-blood-biologics/industry-biologics/covid-19-vaccines-2026-2027-formula-use-united-states-beginning-fall-2026
CDC. National Wastewater Data for Respiratory Viruses. Data for the week ending August 22, 2026; updated August 27, 2026. https://www.cdc.gov/wastewater/respiratory-viruses/national.html
CDC. State and Territory Wastewater Data for Respiratory Viruses. Data for the week ending August 22, 2026. https://www.cdc.gov/wastewater/respiratory-viruses/state.html
CDC. SARS-CoV-2 Variant Proportions. National estimates, four-week period ending August 1, 2026; published August 28, 2026. https://data.cdc.gov/Laboratory-Surveillance/SARS-CoV-2-Variant-Proportions/jr58-6ysp
U.S. Department of Health and Human Services. ACIP Recommends COVID-19 Immunization Based on Individual Decision-making. September 19, 2025. https://www.hhs.gov/press-room/acip-recommends-covid19-vaccination-individual-decision-making.html
CDC. People with Certain Medical Conditions and COVID-19 Risk Factors. https://www.cdc.gov/covid/risk-factors/index.html
National Center for Health Statistics. Prevalence of Overweight, Obesity, and Severe Obesity Among Adults Age 20 and Older: United States, 1960-1962 Through August 2021-August 2023. https://www.ncbi.nlm.nih.gov/books/NBK621182/
CDC advisers vote that patients must consult a health care provider for Covid-19 vaccination, but no prescription required. CNN, September 19, 2025. https://www.cnn.com/2025/09/19/health/cdc-acip-hepatitis-mmrv-covid-vaccine
Kates J, Bell C, Michaud J, Williams E, Tolbert J. Tracking State Actions on Vaccine Policy and Access. KFF, September 24, 2025. https://www.kff.org/state-health-policy-data/tracking-state-actions-on-vaccine-policy-and-access/
CDC. COVID-19 Vaccination Coverage, Overall and by Selected Demographics and Jurisdiction, Among Adults 18 Years and Older, by Season. National Immunization Survey-Fall Respiratory Virus Module, week ending February 21, 2026. https://data.cdc.gov/d/ksfb-ug5d
Gavi. Eight things you need to know about the new “Nimbus” and “Stratus” COVID-19 variants. June 16, 2025. https://www.gavi.org/vaccineswork/eight-things-you-need-know-about-new-nimbus-and-stratus-covid-variants
U.S. Food and Drug Administration. PAXLOVID Patient Eligibility Screening Checklist Tool for Prescribers. https://www.fda.gov/media/158165/download
CDC. Preventing Spread of Respiratory Viruses When You’re Sick. https://www.cdc.gov/respiratory-viruses/prevention/precautions-when-sick.html
Kompaniyets L, Goodman AB, Belay B, et al. Body Mass Index and Risk for COVID-19-Related Hospitalization, Intensive Care Unit Admission, Invasive Mechanical Ventilation, and Death, United States, March-December 2020. MMWR Morb Mortal Wkly Rep. 2021;70(10):355-361. PMID 33705371. https://pubmed.ncbi.nlm.nih.gov/33705371/
van der Klaauw AA, Horner EC, Pereyra-Gerber P, et al. Accelerated waning of the humoral response to COVID-19 vaccines in obesity. Nat Med. 2023;29(5):1146-1154. PMID 37169862. https://www.nature.com/articles/s41591-023-02343-2
Piernas C, Patone M, Astbury NM, et al. Associations of BMI with COVID-19 vaccine uptake, vaccine effectiveness, and risk of severe COVID-19 outcomes after vaccination in England: a population-based cohort study. Lancet Diabetes Endocrinol. 2022;10(8):571-580. PMID 35780805. https://doi.org/10.1016/S2213-8587(22)00158-9
CDC. Staying Up to Date with COVID-19 Vaccines. https://www.cdc.gov/covid/vaccines/stay-up-to-date.html

Mouse on wooden table in rustic cabin with oats, mug, and lantern

What Is Hantavirus? What You Need to Know Right Now

On May 8, 2026September 11, 2026 By Dr. Scott RennieIn Infectious Disease1 Comment

If you’ve been following the news lately, you’ve probably seen hantavirus come up more than once. First it was the tragic death of Betsy Arakawa, the wife of actor Gene Hackman, in Santa Fe in February 2025. Then, just days ago, a cruise ship in the Atlantic became the center of an international health response involving the WHO, multiple governments, and passengers scattered across more than a dozen countries. So let’s talk about what hantavirus actually is, where the risk really comes from, and why one particular strain of this virus is changing how we think about transmission.

The Basics: A Rodent-Borne Illness

Hantavirus isn’t new. In the United States, it first grabbed serious attention in 1993 when healthy young adults in the Four Corners region of the American Southwest started dying of a mysterious respiratory illness. The culprit turned out to be a newly identified pathogen called Sin Nombre virus, spread by the deer mouse. That outbreak gave us a new diagnosis, hantavirus pulmonary syndrome, or HPS, and it launched decades of surveillance that continues today. According to the CDC, from 1993 through the end of 2023, the United States recorded 890 total cases. (1)

In the U.S. strain, the virus spreads from rodents to humans, not from person to person. People get infected when they breathe in aerosolized particles from the urine, feces, or saliva of infected animals. You don’t have to be bitten. You don’t have to handle a dead mouse. You can be sweeping out a shed or a cabin that sat empty all winter, and if infected rodents were living in there, you’re at risk the moment those dried particles become airborne. That’s how Betsy Arakawa most likely got sick. She was found deceased at her Santa Fe home in late February 2025, and the New Mexico Office of the Medical Investigator confirmed she died of hantavirus pulmonary syndrome. (2) Her husband, Gene Hackman, tested negative for the virus and died of heart disease. (2)

That case was a painful reminder. Hantavirus doesn’t make headlines often, but it doesn’t disappear either. New Mexico, Colorado, Arizona, and the broader Southwest are endemic areas. We see cases here. Our patients are at risk.

What the Disease Actually Looks Like

The illness comes in stages. The early phase looks frustratingly like the flu: fever, muscle aches, headache, fatigue, sometimes nausea, vomiting, and diarrhea. (3) That prodromal period can last several days. Then comes the part that kills people. The lungs fill with fluid. Patients develop acute respiratory distress syndrome. Blood pressure drops. The heart begins to fail. According to the WHO, the case fatality rate for hantavirus in the Americas reaches up to 50%. (4) The CDC and other sources put HPS mortality in the 30 to 40 percent range, depending on the strain. (5)

There’s no specific antiviral treatment that works for HPS. Ribavirin, a drug that works for some other viral hemorrhagic fevers, was tested and didn’t show benefit. (6) What we have is supportive care: ICU management, mechanical ventilation when respiratory failure sets in, careful fluid management to avoid making pulmonary edema worse. The CDC is clear that if you suspect HPS, get the patient to the ICU immediately, before you even have lab confirmation. (6) Without early aggressive care, most deaths occur within 24 to 48 hours of the cardiopulmonary phase onset. (6)

This is a disease where the clock moves fast once it turns.

Andes Virus: A Different Transmission Pattern

Here’s where things get more complicated. Most hantaviruses, including Sin Nombre, the strain we deal with in the U.S., don’t spread person to person. A patient with HPS from Sin Nombre is, for practical purposes, a dead end for transmission. Standard precautions are appropriate. That’s reassuring.

The Andes virus is different.

Andes virus is found in South America, primarily Argentina and Chile, and it’s carried mainly by the pygmy rice rat. (7) It’s the only hantavirus known to be capable of human-to-human transmission. (8) That capacity was first documented in a 1996 outbreak in southern Argentina, where 18 cases occurred in and around the towns of El Bolson, Bariloche, and Esquel. Notably, five of the patients were physicians, three of whom had directly cared for infected patients. (9) Two additional people who had contact with the patients but hadn’t visited the affected area also got sick, which strongly suggested person-to-person spread. That outbreak was significant. It forced a rethinking of how we approach Andes virus cases in clinical settings.

The transmission appears to happen through close, sustained contact with an infected person, likely through respiratory secretions. It isn’t casual. It’s not the kind of spread you get from being in the same room briefly. But it happens, and it happens enough that the WHO has classified hantaviruses as emerging priority pathogens with high potential to spark international public health emergencies. (10)

The Cruise Ship: A Real-Time Case Study

What’s unfolding right now on the MV Hondius, a Dutch-flagged expedition cruise ship, is the most visible illustration of Andes virus transmission risk in years.

The ship departed Ushuaia, Argentina on April 1, 2026, carrying 147 passengers and crew from 23 countries. The leading theory, according to Argentine health officials, is that a Dutch passenger couple contracted the Andes virus during a bird-watching trip in Ushuaia before boarding. Investigators believe the couple may have been exposed at a landfill during that outing, where infected rodents were present. (11) They had been traveling through Argentina, Chile, and Uruguay for months prior, passing through areas where Andes virus is endemic. (11)

Two people got sick. What makes this case significant is what happened next. By the time the WHO was notified on May 2, 2026, there were already multiple cases on board. As of today, May 8, 2026, there are nine suspected cases, six confirmed, and three deaths. (12) Patients are hospitalized in South Africa, Germany, the Netherlands, Switzerland, and Saint Helena. (12) The WHO has acknowledged that some cases among close contacts, including cabin-sharing passengers, may represent person-to-person transmission. (13) That distinction is critical. The initial infections almost certainly happened on land in South America. But the chain didn’t stop there.

A WHO epidemiologist noted at a briefing that “we do believe that there may be some human-to-human transmission happening among really close contacts, the husband and wife, people who’ve shared cabins.” (14) This is how Andes virus behaves when it gets into a confined space with sustained close contact. It doesn’t spread like a respiratory virus through casual exposure. But it can move.

The infected passengers came from multiple countries, disembarked at multiple ports before the outbreak was understood, and are now dispersed globally. Health authorities in the U.S. are monitoring former passengers in at least five states. (15) No Americans have shown symptoms as of this writing. The WHO’s assessment is that the global public health risk remains low, and WHO Director-General Tedros has stated that a large epidemic similar to COVID-19 is not anticipated. (15) That assessment reflects what we know about Andes virus: its person-to-person transmission is real but limited, and typically tied to close, prolonged contact rather than broad community spread.

The Argentina Context: Cases Are Rising

This is happening against a backdrop of a significant increase in hantavirus cases in South America. Argentina has recorded 101 confirmed hantavirus cases since June 2025, roughly double the 57 cases recorded in the same period the year before. (16) The mortality rate in Argentina’s current season has been approaching one-third of confirmed cases. (17) Chile has confirmed 39 cases through May 2026, already approaching its full-year 2025 total, with a fatality rate around 33%. (18)

Researchers and health officials point to climate change as a contributing factor. Warming temperatures and shifting rainfall patterns are expanding the habitat of infected rodents, allowing them to move into areas that weren’t previously endemic. (17) More rodents in more places means more exposure risk for more people.

This isn’t a fluke uptick. It’s a trend that warrants attention.

What This Means for Clinicians and Patients

In my practice here in Colorado, I haven’t had a hantavirus case this season. None yet. For patients in the American Southwest generally, the risk remains what it has been: don’t disturb rodent habitats without protection. If you’re cleaning out a garage, barn, cabin, or shed that may have had rodent activity, wet the area down with a disinfectant before sweeping. Don’t dry-sweep. Use gloves and, ideally, an N95 mask. Ventilate the space well before working in it. Those measures aren’t complicated, but they genuinely matter. (19)

For clinicians, the Andes virus situation is a reminder: take travel history seriously. Ask about travel. Every time. A patient presenting with a febrile illness and early respiratory symptoms who recently traveled to Argentina, Chile, or Uruguay deserves a careful look, and the incubation period for hantavirus is one to six weeks after exposure (3), so someone who bird-watched in Ushuaia in early April might not get sick until May. If a patient’s rapid flu test is negative, their COVID test is negative, and they look like they’re heading toward respiratory compromise, hantavirus should be in your differential.

If you’re dealing with a confirmed or suspected Andes virus case, talk to your infection control team. The evidence for person-to-person transmission isn’t theoretical. The 1996 Argentine outbreak included healthcare workers. The WHO and CDC guidance is clear that for Andes virus, standard precautions aren’t sufficient. Enhanced droplet and contact precautions are appropriate. (8)

There’s no vaccine. There’s no proven antiviral. Early ICU admission genuinely changes outcomes. A study using convalescent plasma from HPS survivors showed a reduction in mortality from 32% to 14% in one analysis. (20) That approach isn’t widely available, but it’s worth knowing exists.

The Bottom Line

Hantavirus isn’t new, but the Andes outbreak is a reminder that a rare disease still deserves a place in the differential.

For our patients here in Colorado, the message is straightforward: rodent exposure is the primary risk, and it’s avoidable with the right precautions. For those traveling to South America, know that the Andes virus is endemic there and that the current season has been severe. For clinicians seeing febrile illness with respiratory symptoms, keep a broad differential and ask about travel.

This week, if you’re clearing out a shed, barn, or cabin that sat closed over the winter, wet it down before you touch it. Wear a mask. Don’t dry-sweep.

Measles Is Back: What Urgent Care and Telemedicine Clinicians Need to Watch For

On February 27, 2026September 11, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Measles is back in our daily practice in a way many of us have never seen in our careers. In just the first weeks of 2026, the United States has already recorded more than 900 confirmed measles cases, with most linked to active outbreaks rather than isolated travel related infections. Those numbers are not abstract. They reflect real patients who often first appear with what looks like an ordinary viral upper respiratory infection.

In Virginia, where some of my colleagues practice, the health department has already confirmed 10 measles cases this year, the majority in young children in the Northern region. Public exposure sites in that region now include grocery stores, urgent care centers, emergency departments, churches, and big box retailers, with symptom watch dates stretching into early March. That list reads like a map of daily life, which is exactly the point. Measles is circulating in the same spaces our patients and our own families move through every day.

Clinically, we know this pattern. Early measles often looks like influenza or another common respiratory virus, with fever, cough, coryza, and conjunctivitis. The rash, when it appears, typically starts on the face or hairline and then spreads down the body over several days. The catch is timing. Patients are contagious for about four days before the rash and about four days after it appears, which means they have already spent several days at work, school, religious services, or stores while shedding virus. On a virtual visit, we are often meeting them right in the middle of that window.

On a 24/7 virtual care platform, measles usually does not present with a red flag label in the chief complaint. Instead, it shows up as “fever and cough,” “pink eye,” or “rash on face” typed into a symptom field at 10 p.m. A typical encounter might start with a parent worried about a toddler who has had three days of high fever, a worsening dry cough, a streaming nose, and eyes that are red and watery. The parent may have tried acetaminophen and fluids at home and is now concerned because the child just looks wiped out. At that point there may be no rash, or the parent might mention a few faint spots on the forehead that they are not sure about.

The current outbreaks highlight just how contagious measles is. The virus lives in the nose and throat and is released into the air when an infected person breathes, coughs, or sneezes. It can remain viable in the air or on surfaces for up to two hours after the person leaves. This is why unannounced walk ins to clinics or emergency departments are so risky and why strict infection control and coordination with public health are not optional. One infectious patient who sits in a crowded waiting room can trigger a long chain of secondary cases.

From an epidemiologic standpoint, the current U.S. numbers are sobering. As of mid to late February 2026, national case counts have passed 900 and are now over 1,100, with infections documented in more than two dozen states. A large share of these cases are tied to ongoing outbreaks that began in 2025 and spilled into this year. The vast majority of patients are unvaccinated or have unknown vaccination status, often children and adolescents. Hospitalization rates vary by age, but recent CDC data show that even in 2024, several percent of cases required inpatient care, with higher risk among young children and adults. Measles can lead to pneumonia, encephalitis, and death, even in high resource settings.

On the Virginia Department of Health dashboard, six of the ten cases reported in 2026 have occurred in children under five years old, a group that cannot always be fully immunized yet and that we worry about the most. That number is the one I keep coming back to. Exposure notifications list locations like a grocery store in Lorton, multiple retail sites and restaurants in Manassas, a church, and an office building in Alexandria, each with specific time windows and follow up symptom watch dates 21 days out. It is easy to imagine the scenarios. A preschooler with early measles sitting in a shopping cart. A young adult with mild symptoms walking into an urgent care center after work. These are ordinary moments that turn into public health events.

For virtual care clinicians, the practical question is what to do when that next “simple viral illness” consult pops up in the queue. First, we cannot afford to ignore vaccination status. Every patient with upper respiratory symptoms, especially in outbreak regions, should be asked directly about MMR doses and prior measles infection. This includes adults who vaguely recall “getting shots as a kid” but are not sure which ones. Second, we need to look closely at risk factors: unvaccinated or incompletely vaccinated patients, infants who are too young for full immunization, immunocompromised individuals, pregnant patients, and anyone with recent travel to areas with known outbreaks or exposure to crowded settings.

When clinical suspicion is high, escalation needs to happen quickly and in a structured way. Patients should be referred for immediate in person evaluation and diagnostic testing in a setting that is prepared to implement airborne precautions. Instead of showing up unannounced at a clinic or emergency department, patients should call ahead, so infection prevention teams can arrange safe arrival and isolation. Coordination with local health departments is key. I haven’t hit real friction getting a family to follow that plan, since I haven’t had a suspected measles case reach that point yet. What I do run into, often, is patients, mostly kids, who are unvaccinated because a parent made that choice on purpose and says so plainly when I ask. On the Virginia site, there is even a specific survey link for people who may have been exposed, which triggers public health follow up. Similar mechanisms exist in other states and are often underused.

Virtual clinicians also have a clear boundary here. On the Teladoc platform, for example, management of suspected or confirmed measles is explicitly prohibited, and all such cases must be referred to in-person care. That restriction exists because measles care and infection control require physical assessment, access to testing, immunoglobulin and vaccine for post-exposure prophylaxis, and the ability to initiate supportive treatment for complications, none of which can be delivered over video.

Vaccination remains the core prevention strategy. Two doses of MMR vaccine provide about 97 percent protection against measles. Breakthrough infections can occur, but they are uncommon, and most cases in the current outbreaks are in people who are unvaccinated or not fully vaccinated. The Virginia data show that over 90 percent of the state’s population, and roughly 95 percent of kindergarteners, are vaccinated against measles, yet small pockets of under vaccination have still allowed the virus to spread. In every virtual encounter, we have a chance to answer questions, correct misinformation, and nudge patients toward getting up to date on their shots.

I haven’t personally managed a confirmed measles case over telemedicine. But here’s the kind of scenario clinicians in virtual care should be watching for, a hypothetical built from the pattern these outbreaks produce, not a real patient of mine: A college student logs on late at night with a fever, sore throat, and mild cough after returning from a service trip where they worked in crowded community settings. They mention that their university recently sent out an email about a measles exposure but they “think” they had all their vaccines as a child. As the clinician, you dig a little deeper, learn there is no documentation of a second MMR dose, and find that the student has started to notice a faint rash near the hairline. In that moment, treating this as a routine viral upper respiratory infection would be a miss. Instead, you walk the student through the concern for measles, arrange urgent in person evaluation, instruct them to call ahead before arrival, and notify your internal public health liaison to coordinate with the local health department. That single decision can prevent dozens of secondary cases in a dormitory and on campus.

The current surge of measles cases is a reminder that this disease remains an ongoing threat, one that follows gaps in vaccination and public health infrastructure. For those of us working in virtual care, our role is to keep it on the differential, ask the extra questions, recognize the pattern a day or two earlier, and move swiftly when suspicion is high. The work can feel routine until it is not. Two years ago I wasn’t asking about immunization status at every visit. I do now, at any health-related visit, and especially with kids. I’ve also changed how I handle a rash over video, because video alone is generally not as good quality as a high-resolution photo. Getting a usable photo takes some coaching. The patient needs to stand back far enough, get the angle right, and hold the phone steady so it isn’t blurry. I like a distance shot to see the whole pattern and a macro shot up close if the patient can manage it.

Centers for Disease Control and Prevention. Measles Cases and Outbreaks. Updated February 26, 2026. Available at: https://www.cdc.gov/measles/data-research/index.html. Accessed February 27, 2026.

Centers for Disease Control and Prevention. Measles Vaccination. Updated December 29, 2025. Available at: https://www.cdc.gov/measles/vaccines/index.html. Accessed February 27, 2026.

Centers for Disease Control and Prevention. Measles, Mumps, and Rubella (MMR) Vaccination: Information for Healthcare Professionals. Updated January 25, 2026. Available at: https://www.cdc.gov/vaccines/hcp/by-disease/mmr.html. Accessed February 27, 2026.

Virginia Department of Health. Measles. 2026. Available at: https://www.vdh.virginia.gov/measles/. Accessed February 27, 2026.

Virginia Department of Health, Office of Emergency Preparedness. VDH OEP Weekly Situation Update. Published February 19, 2026. Available at: https://www.vdh.virginia.gov/emergency-preparedness/2026/02/20/vdh-oep-weekly-situation-update-137/. Accessed February 27, 2026.

Virginia Department of Health. Virginia Health Officials Investigating Two Confirmed Measles Cases in Northern Virginia. News release, February 18, 2026. Available at: https://www.vdh.virginia.gov/news/public-relations-contacts/2026-regional-news-releases/virginia-health-officials-investigating-two-confirmed-measles-cases-in-northern-virginia/. Accessed February 27, 2026.

Robinson A. VDH: Measles outbreak not likely in Northern Virginia despite uptick in cases. ALXnow. Published February 22, 2026. Available at: https://www.alxnow.com/2026/02/23/vdh-measles-outbreak-not-likely-in-n-va-despite-uptick-in-cases/. Accessed February 27, 2026.

WSBT / Sinclair Broadcast Group. Measles cases surpass 1,100 so far in 2026 as outbreaks continue to spread. Published February 26, 2026. Available at: https://wsbt.com/news/nation-world/us-measles-cases-surpass-1100-so-far-in-2026-health-experts-warn-centers-for-disease-control-and-prevention. Accessed February 27, 2026.

I hear it almost every day now. “I think I just need a Z-Pak.”

On January 2, 2026September 11, 2026 By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Sometimes it’s phrased as a question. Sometimes it isn’t. In telemedicine especially, many patients request azithromycin by name within the first minute of the visit. The symptoms are familiar. Runny nose. Congestion. Post-nasal drip. Scratchy throat. Maybe a cough that started yesterday. No fever. No shortness of breath. No focal findings anyone could reasonably point to as bacterial.

But they’re convinced the Z-Pak will help them get better faster. They’ve taken it before. It worked last time. Or at least they felt better a few days later and connected the dots.

This didn’t happen by accident.

Azithromycin earned its place in outpatient medicine because it was easier to tolerate than older antibiotics like erythromycin, had fewer drug interactions than clarithromycin, and came packaged in a way that felt efficient. Six pills. Five days. Done. The Z-Pak became a symbol of modern medicine that didn’t slow you down.

Over time, it also became the antibiotic people expected.

In telemedicine, that expectation is even stronger. There’s no exam table. No stethoscope. No labs. No chest X-ray down the hall. The visit is brief by design. When a patient feels sick and wants something tangible, the Z-Pak becomes the path of least resistance. Prescribing it can shorten the encounter. It avoids a long explanation. It reduces the risk of a bad review. It keeps patient satisfaction scores high. It keeps supervisors and clinic managers happy. Everyone moves on to the next visit.

I understand why this happens. I’ve seen it from the inside.

But convenience doesn’t make a treatment safe or appropriate.

Azithromycin does not treat viral infections. It does not help the common cold. It does not clear post-nasal drip. It does not shorten the course of uncomplicated upper respiratory infections. When patients feel better after taking it, they almost always would have improved anyway.

What it does do is expose people to real risk.

Azithromycin can prolong the QT interval. That matters. QT prolongation can predispose patients to dangerous heart rhythms, including torsades de pointes and sudden cardiac death. This risk is higher in people with underlying heart disease, electrolyte abnormalities, or those taking other QT-prolonging medications, but it is not zero in otherwise healthy adults. Large observational studies have shown an increased risk of cardiovascular death during azithromycin treatment compared with other antibiotics or no antibiotics at all.

That risk is invisible to patients. They don’t feel their QT interval getting longer. They just know they want something to help them feel better.

Antibiotics also carry more familiar side effects. Nausea. Diarrhea. Abdominal cramping. Yeast infections. Rashes. Allergic reactions. These are not rare, and they are not trivial when the medication wasn’t needed in the first place.

Then there’s resistance. Every unnecessary antibiotic course applies selective pressure. Azithromycin resistance is already a growing problem in common respiratory pathogens. When we reach for it reflexively, we make it less useful for the patients who actually need it.

The harder part of these visits is the explaining.

It takes longer to walk someone through why their symptoms are viral. Why time, fluids, nasal saline, antihistamines, or intranasal steroids actually help. Why rest matters. Why antibiotics won’t fix inflammation or mucus production. Why feeling miserable does not automatically mean something dangerous is happening.

It’s much faster to send a prescription.

But faster is not better medicine.

I get patients asking for Z-Paks every day that I work in telemedicine. It’s so common that it happens at least once a day, if not three or four times a day. One example sticks with me. A patient requested a Z-Pak for congestion and sinus pressure that had been present for two days. No fever. No facial pain. No worsening course. When I explained why antibiotics wouldn’t help, they were frustrated at first. We talked through what sinus infections actually look like and when antibiotics are appropriate. We discussed symptom control instead. Two days later, they messaged to say they felt better and were glad they didn’t take an antibiotic they didn’t need.

That outcome required time. It required education. It required saying no.

Not every visit goes that smoothly. Some patients remain disappointed. Some leave poor reviews. That pressure is real, especially in high-volume telemedicine environments.

But prescribing antibiotics to keep the peace comes at a cost. It shifts risk onto the patient. It shifts harm into the future. And it reinforces the idea that medicine should always offer a pill, even when the best treatment is patience and support.

Azithromycin became dominant because it was easy. That same ease is why we need to be more careful with it now.

The 1963 to 1967 problem

If you were born before 1957

Should you get a titer drawn?

About the death count, since you will see it argued about

What I would actually do

The Bottom Line

Related Reading

Sources

A 28-year-old lab tech, four days, and a death certificate that says pneumonia

The part of this that got reported backward

Two different words that look identical

Could a broken tube really do this?

Was it resistant? Was it modified?

The institute, and the thing that is actually true about it

Running the conspiracy theories down

Can we believe them?

Is this the next COVID?

So should you buy N95s?

The Bottom Line

Related Reading

Sources

What last season looked like

What changed in this year’s shot

Who is actually making the recommendations this year

September or October? My answer depends on your age

If you are 65 or older, ask for the stronger shot

FluMist, now at home

If you get the flu anyway: the 48-hour window

For patients

For clinicians

The Bottom Line

Related Reading

Sources

Where the label usually comes from

The label is not free

There is a score for this, and it runs on history alone

What I actually do with this on a video visit

What a real reaction looks like, and what has changed about treating it

For patients

For colleagues

The Bottom Line

Related Reading

Sources

Start with the boring part, because it is the part that matters

The dementia finding, and the catch

What I actually think about it

The part that belongs to my day job

If you already have it, the clock is the thing

For patients

For colleagues

The Bottom Line

Related Reading

Sources

Itching is not the same as infestation

How to tell persistent itch from actual failure

Failure is more common than people think

The boring reasons treatment fails

The lumps that stay for months

When the itch is not scabies at all

What I ask for on a video visit

For patients

For colleagues

The Bottom Line

Related Reading

Sources

What was approved, and when you can actually get it

Where the virus is right now

The page to bookmark

Who the FDA says can get it

The high-risk list is longer than you think

Do you need a note from your doctor?

Why I think the restrictions backfire

Has the virus changed?

How long do you stay home?

What else lowers your risk

For patients

For colleagues

The Bottom Line

Related Reading

Sources