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.

Related Reading

2026-2027 COVID Vaccine: Who Qualifies, and Do You Need a Doctor’s Note?
Flu Prevention: Vaccines, Symptoms, and Treatment Options
When to Use Telemedicine vs. Urgent Care: How I Spot the Sick One
I hear it almost every day now. “I think I just need a Z-Pak.”

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

1. 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
2. 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/
3. Centers for Disease Control and Prevention. 2026-2027 Flu Season. Updated September 2, 2026. https://www.cdc.gov/flu/season/2026-2027.html
4. 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
5. 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/
6. 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
7. 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
8. 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
9. BioPharma Dive. FDA approves Moderna’s mRNA flu vaccine. August 2026. https://www.biopharmadive.com/news/moderna-fda-approve-mflusiva-seasonal-influenza/826864/
10. 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
11. Centers for Disease Control and Prevention. Influenza Antiviral Drug Baloxavir Marboxil. https://www.cdc.gov/flu/treatment/baloxavir-marboxil.html
12. 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
13. 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
14. 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