Yes. If you had the flu this season and haven't been vaccinated, you should still get a flu shot, because this season's vaccine protects against 3 different flu viruses and you likely caught just 1. If you're still moderately or severely sick, wait until you've recovered. Once you're better, there's no need to put it off.
Why get a flu shot if I already had the flu?
More than 1 kind of flu goes around each year. The US flu vaccine is trivalent: it covers 1 influenza A(H1N1) virus, 1 influenza A(H3N2) virus, and 1 influenza B virus.
Getting sick with 1 flu virus doesn't mean you're protected from the others. The CDC explains that immunity to 1 flu virus will not necessarily protect you against a different one. The FDA says that if you were sick with flu this season and weren't vaccinated, getting the vaccine is still important because it covers 3 different strains.
- You likely caught just 1 flu virus. The FDA notes the vaccine can still protect you against the other strains in the shot.
- You may not know which one you had. So there's no way to be sure you're already covered.
- Flu season runs for months. The CDC advises vaccinating throughout the season while flu viruses are spreading.
How long should I wait after the flu to get the shot?
There's no set number of days. The CDC's rule is about how sick you are, not the calendar. People with a minor illness, like a cold, may be vaccinated. People who are moderately or severely ill should usually wait until they recover.
No source gives a checklist for "recovered". A sensible sign is that your fever is gone and you feel mostly back to normal. If you still have leftover symptoms and aren't sure they count, ask the pharmacist or your clinician before the shot.
Is it too late in the season to get it?
Usually not. The CDC's ideal target is September or October, but its guidance says vaccination should continue after October and throughout the flu season. The FDA adds that the vaccine is still beneficial if you get it after October.
Keep in mind it takes about 2 weeks after the shot for protective antibodies to develop. Sooner after you recover is better than later.
Does Tamiflu change the timing?
Not for the flu shot. The CDC says a flu shot can be given to people taking flu antivirals. The antiviral timing rules apply only to the nasal spray flu vaccine (FluMist), which uses a weakened live virus that antivirals can interfere with.
If you want the nasal spray, the CDC says it can be affected if you took oseltamivir (Tamiflu) or zanamivir within 48 hours before it, peramivir within 5 days before, or baloxavir (Xofluza) within 17 days before, or any of these in the 2 weeks after. If that happens, the CDC advises getting a flu shot instead. These windows can be longer for people with kidney problems, so tell the pharmacist which antiviral you took and when.
When should you get care?
In an emergency, call 911Get medical care right away (the same day) if your fever or cough got better and then came back or got worse, or if a chronic condition like asthma, diabetes, or heart disease is getting worse.
For a child, get medical care right away for any fever in a baby younger than 12 weeks, a fever above 104°F that medicine doesn't bring down, signs of dehydration (no urine for 8 hours, dry mouth, no tears when crying), not being alert or interacting when awake, or severe muscle pain where the child refuses to walk.
Call 911 for trouble breathing or fast breathing, chest or belly pain or pressure that won't go away, confusion or being hard to wake, a seizure, not urinating, severe weakness or unsteadiness, or in a child, bluish lips or face or ribs pulling in with each breath.
How our AI doctor decides when to send you to care ›What if I already had a flu shot and still got the flu?
Usually not. The CDC recommends 1 dose of flu vaccine each season for people 9 and older, so if you already had this season's shot, you're done. The exception is some children ages 6 months to 8 years who need 2 doses at least 4 weeks apart, depending on their age and vaccine history. Ask your child's doctor or pharmacist if you're not sure.
Getting the flu after a shot doesn't mean it failed completely. The CDC notes that studies show vaccination can reduce how severe the illness is in people who still get sick.
Common questions
Can I get a flu shot after having the flu?
Yes. This season's vaccine covers 3 different flu viruses, and having 1 of them doesn't protect you from the others. Wait until you've recovered if you were moderately or severely sick, then get vaccinated.
Can I get the flu twice in one season?
It's possible. Several flu viruses circulate each season, and the CDC says immunity to 1 flu virus will not necessarily protect against a different one. That's the main reason the shot is still worth getting after you've had flu.
Do I need a flu test to prove I had it before the shot?
No. The CDC recommends a yearly flu vaccine for everyone 6 months and older without a medical reason not to get one. Whether you had flu this season doesn't change that, so no test is needed.
I still have a cough. Can I get the shot?
Possibly. The CDC says people with a minor illness may be vaccinated, and those who are moderately or severely ill should usually wait until they recover. If your fever is gone and you just have a leftover cough, mention it at the pharmacy and they can help you decide.
Will the shot make me sick again right after the flu?
It can cause short-term side effects. The CDC lists soreness, redness, or swelling where the shot was given, along with fever, muscle aches, or headache. The CDC also says the viruses in a flu shot are inactivated, so you can't get flu from the shot. If you get a high fever or feel much worse, see the care signs below.
Pymander is not a replacement for a physician and does not provide medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition. If you think you may have a medical emergency, call 911.