Most people walk into a pharmacy, roll up a sleeve, and never ask which flu shot they are getting. After 65 that question matters. The immune system responds less strongly to vaccines with age, which is why CDC gives preference to three specific flu vaccines for older adults over the standard dose shot, and why a brand new type of vaccine was approved this year for people 50 and older. This guide explains which flu shot to ask for at 65 and older, when to get it in the 2026 to 2027 season, how it fits with the RSV and COVID-19 vaccines, and why older adults are the group researchers most need when testing the next generation of flu vaccines.
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Why the flu shot matters more after 65
Flu is not an equal opportunity illness. CDC estimates that in recent seasons between 70 and 85 percent of flu related deaths and between 50 and 70 percent of flu related hospitalizations occurred in people 65 and older. Two things drive that. Older adults are more likely to have conditions such as heart disease, COPD, or diabetes that flu can tip into a crisis, and the immune system's response to both infection and vaccination weakens with age, a process called immunosenescence. The practical result is that a standard flu shot produces a smaller protective response in a 72 year old than in a 32 year old, which is exactly the problem the vaccines below were designed to solve. Our guide to flu treatment covers what to do if you do get sick.
Which flu shot to get at 65 and older
For the 2026 to 2027 season, CDC preferentially recommends three vaccines for adults 65 and older over standard dose, unadjuvanted flu shots:
High dose inactivated vaccine (Fluzone High-Dose). Contains four times the antigen of a standard shot, giving the immune system more to respond to.
Adjuvanted inactivated vaccine (Fluad). A standard amount of antigen plus an adjuvant, an ingredient that boosts the immune response.
Recombinant vaccine (Flublok). Made without flu virus or eggs, with three times the antigen of a standard shot.
CDC considers all three preferred and does not rank them against each other, so the right one is usually whichever your pharmacy or clinic has in stock. If none is available, CDC's advice is clear: get a standard dose flu shot rather than delay. The nasal spray vaccine is not approved for people 65 and older. The one question worth asking at the counter is simply, "Is this one of the vaccines recommended for people over 65?"
The new option: the first mRNA flu vaccine
On August 5, 2026, the FDA approved mFLUSIVA, the first flu vaccine in the United States to use mRNA technology, for adults 50 and older. It uses the same approach as the COVID-19 mRNA vaccines, giving the body instructions to make a flu protein rather than delivering the protein itself, and in a trial of more than 40,000 adults it prevented about 27 percent more flu cases than a standard flu shot, with more short-term side effects such as a sore arm, fatigue, and headache.For adults 65 and older it received accelerated approval, and it is not yet among CDC’s preferred vaccines for this age group, although the American Academy of Family Physicians lists it among the enhanced options. Insurance coverage varies this first season. It exists because older adults took part in the trials that tested it, which is the same way the high dose and adjuvanted vaccines reached pharmacies a decade ago. General vaccine research is covered on our vaccine clinical trials page.
When to get your flu shot in 2026
CDC's guidance for the 2026 to 2027 season is to get vaccinated in September or October, and ideally before the end of October, because flu activity often starts rising in October and peaks between December and February, and protection takes about two weeks to build. Adults 65 and older should generally not get the shot in July or August, since protection fades over the months and may be weaker by the end of the season. If it is already November or later, vaccination is still worthwhile for as long as flu viruses are circulating, which often means spring. One shot covers the season.
Flu, RSV, and COVID-19 shots: can you get them together?
Yes. CDC allows the flu, COVID-19, and RSV vaccines to be given at the same visit for people who are eligible for each, which saves a trip and makes it less likely one gets skipped. The 2026 to 2027 COVID-19 vaccine is recommended for all adults, and RSV vaccination is recommended for adults 75 and older and for younger adults from 50 with certain health conditions; unlike the flu shot, the RSV vaccine is not repeated every year. Some people prefer to space the shots a few days apart to tell which one caused a sore arm, and that is fine too. Our guides explain RSV in adults and COVID-19 research.
Why researchers need people over 65 for flu vaccine studies
Every flu vaccine designed for older adults was proven in older adults, and the next ones will be too. Because immune responses weaken with age, a vaccine that works well in 30 year olds may not work in 75 year olds, so regulators require studies in the age group that will actually use it. That is why flu vaccine trials actively recruit adults 65 and older who are generally healthy or medically stable, have not yet had this season's flu shot, and have not had the flu in the past several months. In many of these studies the new vaccine is compared with an approved flu vaccine rather than a placebo, so taking part does not mean going without a flu shot; each listing explains its own design. People with weakened immune systems, a history of severe allergic reaction to a vaccine, or a history of Guillain-Barré syndrome are usually excluded, for their own safety.
How to find a flu vaccine study for adults 65 and older
AllClinicalTrials.com lists vaccine studies recruiting across the US, including studies built specifically for older adults. Right now that includes a flu vaccine study for adults 65 and older who have not yet had this season's flu shot and a second flu vaccine study for the same age group; both seek people who are generally healthy or medically stable, with no major health changes or hospital stays in the past three months. Timing matters more than usual here: because both studies require that you have not had a flu vaccine in the past six months, the window to join is before you get your routine shot, not after. The application takes about 5 minutes: you answer questions about your age, general health, and recent vaccines, and if a study near you looks like a match, the research team contacts you. Nothing is decided until you have gone through informed consent, and participation is voluntary at every step. Our guide explains how long vaccine clinical trials take.
Three things to have ready: the date of your last flu shot, any flu illness in the past year, and a list of your current health conditions and medicines. Those three answers decide eligibility for most vaccine studies in older adults.
Common questions
What is the best flu shot for seniors? CDC preferentially recommends three for adults 65 and older: high dose (Fluzone High-Dose), adjuvanted (Fluad), and recombinant (Flublok). It does not rank them against each other, so any of the three is a good choice, and a standard shot is better than none if they are unavailable.
When should seniors get the flu shot in 2026? In September or October, ideally by the end of October, and not in July or August, because protection fades over the season. If you missed that window, getting vaccinated later is still worthwhile.
Can people over 65 get the new mRNA flu vaccine? Yes. mFLUSIVA, approved in August 2026, is approved for adults 50 and older, including those 65 and older. Ask your doctor or pharmacist whether it is available and covered for you.
Can I get the flu shot and the RSV vaccine at the same time? Yes. CDC allows flu, RSV, and COVID-19 vaccines to be given at the same visit for people eligible for each. The RSV vaccine is not an annual shot.
Why does the standard flu shot work less well after 65? Because the immune system's response to vaccines weakens with age. The enhanced vaccines compensate with more antigen or an adjuvant, which is why CDC prefers them for older adults.
Does joining a flu vaccine study mean skipping my flu shot? Not usually. Many studies in older adults compare a new vaccine with an approved flu vaccine, so everyone is vaccinated; the listing explains the design. Studies do require that you have not already had this season's shot, so the time to apply is before your routine vaccination.
Who cannot join a flu vaccine study? Typically people with weakened immune systems or on immune suppressing medicines, anyone with a history of severe allergic reaction to a vaccine or of Guillain-Barré syndrome, and people who had a flu vaccine in the past six months or the flu in the past several months. Each study lists its own rules.
Do flu vaccine studies pay? Some studies offer compensation for time and travel, and study related care is typically provided at no cost to participants. Compensation varies by trial and is always described during the informed consent process before you agree to anything. Our guide to how clinical trials pay explains the details.
See influenza clinical trials recruiting now
Browse open studies, filter by location, and apply in about 5 minutes: Influenza Clinical Trials.