QUESTION: “When is the ideal time to stop in to get a flu shot? If I receive it too early in the season will I still be protected at the end of flu season? “

ANSWER: The best time to get your flu shot is before the end of October. Protection lasts for up to a year for most individuals (see below*).

A few things to consider about the timing of your flu shot:

  • It takes roughly 2 weeks from the day you get your shot for your body to build an immune response to protect yourself from the flu.
  • Peak flu season has historically been from December-February:

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  • Ensuring that the majority of the population is immunized before the flu comes about can dramatically reduce the rate of transmission and save lives. This is sometimes referred to as “herd immunity”.
  • Children 6 months to 8 years of age receiving their first flu shot require 2 doses.
    • It is recommended that children be immunized as soon as possible since the second dose must be given > 4 weeks after the first.

*In regards to the immunization “wearing off” too soon:

  • Data suggests that elderly patients > 65 years of age who receive their flu shot very early (eg July) may result in reduced protection later in the season. Protective antibody levels decline over time, but other studies show that protection can persist for over a year in the general population.
    • Remember, the reason we re-immunize for the flu each year is not because the previous vaccine has “worn off”; the flu virus itself changes each year, therefore the annual immunization is re-designed to protect you from those anticipated yearly changes.

Overall, it is recommended to receive your flu shot as soon as it is readily available (eg by the end of October) to ensure protection throughout the entire flu season. Even if it is late in the season, there is still benefit in receiving your flu shot.

Pharmacists can be a great resource for getting the health information you need. Your pharmacist can assist you with any questions or concerns about the appropriateness and timing of immunization, therefore it’s best to Ask The Pharmacist about your flu shot today!





[Bresee, Joseph MD, Broder, Karen MD, Grohskopf, Lisa MD, et al. ][Prevention and Control of Seasonal Influenza with Vaccines Recommendations of the Advisory Committee on Immunization Practices — United States, 2016–17 Influenza Season]. MMWR Recomm Rep 2016;65(No. RR-5):[1-56].