When Are the Best and Worst Times to Get a Flu Shot?

Shandra Martinez

| 3 min read

Doctor vaccinating child, kid with mother at hospital.
There is a familiar refrain we’ll be hearing a lot over the next few months as we go to doctor appointments, or stop by the pharmacy to pick up prescriptions: “It’s flu season. Have you had your flu shot already?” As we enter the months that typically see influenza cases ramp up across the United States, lots of information about the 2021-22 flu season is at your fingertips, including what four common flu strains this year’s shot is designed to ward off. But let’s answer one of the basic questions first: When are the best and worst times to get a flu shot?
Best time to get a flu shot. Because contracting the flu can be dangerous – leading to thousands of hospitalizations and deaths in a typical year – it’s always a good time to get vaccinated against the seasonal flu. The best time to get your annual flu shot is September, October, and anytime after that when influenza viruses are spreading in your community, according to the Centers for Disease Control and Prevention. Here are some other flu shot timing guidelines from the CDC:
  • Everyone 6 months old and older should get an annual flu shot. A nasal mist option may also be available. Talk to your healthcare provider if you prefer the mist instead of a shot.
  • Some children ages 6 months to 8 years old might need two doses of the influenza vaccine.
  • Check with your child’s pediatrician about how many doses they will need. Children getting two doses usually get their first dose as soon as the seasonal flu shot is available, then their second dose about four weeks later.
  • Children needing one dose should be vaccinated as soon as it becomes available in their area.
  • While fall is best, getting flu shots in December and January will still offer protection if flu viruses are spreading in your area. So you can still roll up your sleeve for a shot in early 2022.
  • Once you are vaccinated, it takes your body about two weeks to develop the antibodies needed to protect against the flu.
Worst time to get a flu shot. Unless your healthcare provider advises an early vaccine, don’t get your flu shot too early in the season, the CDC advises. What’s too early? July or August is too soon for most people, even though the new seasonal vaccine may already be available in your area. This is especially true for older people, because getting the shot too early in the season could mean they will have reduced protection against getting the flu later in the influenza season.
Why do you need a flu shot? Some people who are on the fence about getting a seasonal flu shot point to last year’s underwhelming number of cases. The 2020-21 flu season was unusually light compared to previous years. Health experts have said a large part of the reason for that likely was our activities during the pandemic, which included social distancing, wearing face masks and being vigilant about washing our hands – behaviors that can also keep flu viruses from spreading.
Looking at the last typical flu season, the CDC estimates that in 2019-20, flu shots prevented more than 7 million flu-related illnesses, more than 100,000 hospitalizations and 6,300 deaths. How bad was that 2019-20 flu season when it came to illnesses and deaths? Here are the estimates:
  • 38 million people had the flu.
  • 18 million people went to a healthcare provider for flu-related symptoms.
  • 400,000 people were hospitalized with flu-related symptoms.
  • 22,000 people died of influenza.
Photo credit: Getty Images

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