Flu Vaccine Timing

“What’s the best time to get a flu vaccine?” “If we get the flu vaccine now, will it last until the end of the season?” These are some of the most common questions patients ask us about flu vaccine timing. In lieu of these questions, the following are some helpful flu vaccine timing tidbits.

Flu vaccines last at least 6 months, although protection decreases toward the end of that time frame. While many worry about getting their vaccine too early, you also want to avoid waiting too long. In short, get your flu vaccine by Halloween.

“Ideal” timing is probably September and October. We say it with quotation marks because we don’t know from year to year when the flu season will start and end. Typically the peak of flu season is November through March. However, we do see cases as early as September and as late as May. 2019 is a perfect example. We saw scattered cases from the 2018-2019 flu season still in May. The first confirmed cases for the 2019-2020 flu season were mid-September.

Remember that it takes 2 weeks for the vaccine to provide protection. For young children who need 2 flu vaccines in the same season, allow 6 weeks total (4 weeks between the 2 vaccines and 2 weeks after the 2nd). These patients should get their 1st vaccine no later than mid-September, if possible.

If it’s early spring and you haven’t had the vaccine, but flu is still going around, a flu vaccine would still benefit you. If uncertain of the benefit, ask your healthcare provider.