2 doctors weighed in:

Long does a flu shot last usually?

2 doctors weighed in
Dr. Joseph Roosth
Internal Medicine
1 doctor agrees

In brief: A year

Good question.
The influenza virus mutates rapidly so each year's vaccine varies as each year's vaccine is based on the most prevalent flu strains from the last flu season. The actual immunity derived from a given flu shot probably lasts more than one year, but it is important to get a new shot each year, due to the changes.

In brief: A year

Good question.
The influenza virus mutates rapidly so each year's vaccine varies as each year's vaccine is based on the most prevalent flu strains from the last flu season. The actual immunity derived from a given flu shot probably lasts more than one year, but it is important to get a new shot each year, due to the changes.
Dr. Joseph Roosth
Dr. Joseph Roosth
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