How Effective Is the Flu Vaccine in 2024?

Alyssa Corso
Alyssa Corso1 Jan 2024
Reviewed and Fact Checked ✔️

Recent studies show that flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population during seasons when most circulating flu viruses are well-matched to those used to make flu vaccines. Flu vaccine effectiveness usually varies from season to season. There are at least two factors that play an essential role in determining the likelihood that vaccination will protect a person from flu illness: 

1) Characteristics of the person being vaccinated (such as their age and health).

2) How well the vaccines "match" the flu viruses spreading in the community.

Mira offers affordable healthcare for just $45 per month. Get access to low-cost lab testing, urgent care visits, and discounted prescriptions. Sign up today.

Flu Vaccine Effectiveness

Since flu vaccine effectiveness varies, researchers and scientists will begin to estimate the effectiveness of the 2023–2024 flu vaccine in the coming months.

However, it's possible to evaluate flu vaccine effectiveness based on data from the previous seasons. Below we analyze flu vaccine effectiveness. 

Flu Vaccine Effectiveness By Year

Below we outline the effectiveness of the flu vaccine by year.

200410 percent
200521 percent
200652 percent
200737 percent
200841 percent
200956 percent
201060 percent
201147 percent
201249 percent
201352 percent
201419 percent
201548 percent
201640 percent
201738 percent
201829 percent
201939 percent

Flu Vaccine Effectiveness By Age Group

There can be a range of variance in flu vaccine effectiveness when it comes to specific age groups. The CDC tracks this data as well as data on the flu's overall effectiveness.

Below we outline flu vaccine effectiveness estimates for all vaccine types across different age groups from the past five flu seasons.

Flu seasonAll ages6 months to 8 years9 to 17 years18 to 49 years50 to 64 years65 years and older
2019–202039 percent34 percent40 percent34 percent40 percent39 percent
2018–201929 percent48 percent7 percent25 percent14 percent12 percent
2017–201838 percent68 percent32 percent33 percent30 percent17 percent
2016–201740 percent57 percent36 percent19 percent40 percent20 percent
2015–201648 percent51 percent59 percent52 percent26 percent42 percent

How Long the Flu Vaccine is Effective For

A flu vaccine should protect you through the current flu season. You'll need to receive another flu vaccine for the next flu season. There are several reasons why a flu vaccine is only effective for one flu season.

  • Influenza viruses change constantly. Because of this, the strains included in this year's flu vaccine may not be the most common strains during next year's flu season.
  • The level of protection (immunity) generated by the flu vaccine wanes over time.

For example, a 2019 study found that, across seven flu seasons, every additional 28 days after vaccination was associated with a 16 percent increase in the likelihood of testing positive for flu.

Health Image

Get affordable doctor copay without paying insurance premiums

Join 39,000 people and get Mira, the best alternative to traditional insurance. Enroll and use immediately. Plans start at only $45/mo.

Alyssa Corso

Alyssa is a Senior Marketing Associate & Content Writer at Mira. She is passionate about educating others on how to affordably access healthcare.

Get Health BenefitsGet Lab TestsTalk Therapy
Get ObamaCare
> See Plans