Not sure who should get a flu shot this year? Nearly everyone aged 6 months and older should be vaccinated before each flu season, with very few exceptions, and adults 65 and older have an extra vaccine type to ask about.
Flu vaccination is one piece of a wider adult routine. The adult vaccine schedule shows where it sits among other shots, and preventive health screenings by age covers the checks that go with it.
If you are not sure the shot applies to you
The flu shot applies to almost every adult. The Advisory Committee on Immunization Practices (ACIP) develops recommendations on how to use vaccines to control disease in the United States, and ODPHP’s page on the ACIP influenza recommendations sets out that role. The practical rule for adults is simple: plan on vaccination before each flu season unless a specific exception applies to you.
Groups that gain the most
Some people face more risk from influenza, so the decision to vaccinate is even easier for them. Superior HealthPlan’s flu guidance names these higher-risk groups:
- Adults 65 and older: this group also has a dedicated vaccine type, covered below.
- Pregnant women: they are listed among the groups at higher risk.
- Young children: children younger than 5 are named in the same list.
- People with weakened immunity or chronic conditions: these conditions raise the stakes of catching the virus.
What the shot protects against
Influenza is more than a bad week in bed. Sharp HealthCare lists complications that include bacterial pneumonia, ear infections, sinus infections and worsening of chronic conditions. It also notes that the flu shot has been shown to reduce flu illness, serious flu complications, and hospitalization or death. That is the case for vaccinating even if you usually feel fine.
If you think last year’s shot still counts
It does not carry over. A flu shot is needed every year for two reasons: the vaccine changes, and your protection fades.
On the first point, the Centers for Disease Control and Prevention (CDC) updates the flu vaccine each year to match the seasonal viruses expected to be most common, as Cornell Health explains. Sharp HealthCare adds that the Food and Drug Administration (FDA) reviews flu activity around the world and picks the strains likely to circulate in the upcoming season. A vaccine built for an earlier season was aimed at different viruses.
On the second point, Sharp HealthCare notes, citing the CDC, that the protection an annual vaccine provides declines over time. Yearly re-vaccination resets that protection against the current strains.
Public health planners treat yearly vaccination as a goal in its own right. Healthy People objective IID-09 aims to increase the proportion of people who get the flu vaccine every year, and its trend is currently marked as getting worse. In practice, skipping a year is common, and that is the gap the objective targets.
If you need to choose a vaccine type
Adults mainly choose between an injected shot and, for some younger adults, a nasal spray. Older adults have one more option.
Standard injected shot
The inactivated (killed) influenza vaccine is injected by needle, typically into the arm muscle, according to Cornell Health. It suits most adults, and it is the form to consider if you are outside the nasal spray age range.
Nasal spray
The nasal spray is only for healthy people ages 2-49, according to KidsHealth. Cornell Health states it is not appropriate for children younger than 2 or for adults 50 and older. If you are 50 or older, plan on an injection.
High-dose flu vaccine for seniors
The high-dose flu vaccine, described by Cornell Health as the senior-dose shot, is designed to give people aged 65 years or older a better immune response. It is the answer to the common question of which flu vaccine is aimed at seniors.
There are trade-offs to weigh. Cornell Health reports that some side effects appear more often than with the regular dose, especially pain, redness and swelling at the injection site. Headache, muscle aches, low-grade fever and malaise are also listed. Its effectiveness compared with the regular-dose vaccine is still being studied, so ask your primary care provider which option fits you rather than assuming one rule applies to everyone.
If you are unsure when and where to go
Get vaccinated before the start of the flu season, and treat the time lag as the deciding factor. The shot takes effect in about two weeks, so Superior HealthPlan warns that people who wait can get sick before it works. Once the antibodies develop, Cornell Health says they protect you for up to a year.
If you have just had flu, hold off briefly. Sharp HealthCare says to wait at least two weeks after a flu diagnosis before receiving your annual shot, and to let other illnesses resolve first.
For location, a pharmacy is a practical choice. Cornell Health describes flu vaccine clinics run in partnership with a pharmacy, and a pharmacist can also tell you whether an egg-free option suits you.
Afterwards, expect some soreness at the injection site. Pain, redness and swelling there are the most frequently reported side effects of the senior-dose shot, and a bandage over the spot is routine.
If you have a health condition or recent illness
A few situations call for a pause or a conversation with a clinician before vaccination. The table below pulls them together.
| Your situation | What to do | Planning use |
|---|---|---|
| Moderate-to-severe illness with a fever | Wait until you recover | Reschedule rather than skip the shot |
| Recent flu diagnosis | Wait at least two weeks | Book the appointment after that window |
| Severe egg allergy, a past severe reaction or past Guillain-Barre syndrome | Consult your physician before vaccination | Raise it before the appointment, not at the counter |
| Age 50 or older | Nasal spray is not appropriate | Plan on an injected shot |
| Age 65 or older | Ask about the senior-dose shot | Discuss it with your primary care provider |
Cornell Health’s flu vaccine guidance and Sharp HealthCare’s advice on vaccination after flu support these points.
Egg allergy deserves a closer look. KidsHealth says people with egg allergies can now get the flu vaccine just like everyone else, while Cornell Health still lists a severe egg allergy as a reason to consult a physician first. If yours is severe, talk to your doctor. Superior HealthPlan notes that an egg-free alternative exists and suggests asking your health care provider or pharmacist whether it is right for you.
Frequently asked questions
| Question | Answer |
|---|---|
| Can the flu shot give me the flu? | No. Cornell Health states that the shot does not cause flu, and that antibodies develop within about two weeks. |
| Do healthy adults really need it? | Yes. Superior HealthPlan points out that healthy people can still carry the flu virus and spread it to others without showing symptoms. |
| Is it necessary to repeat the flu shot every year? | Yes. The vaccine is updated for each season’s expected viruses, and protection from an earlier shot declines over time. |
| Who should talk to a doctor first? | Anyone with a severe egg allergy, a past severe reaction or past Guillain-Barre syndrome, and anyone currently ill with a fever. Adults 65 and older can also ask about the senior-dose shot. |
