Should you get your flu shot now or later?

Health officials sometimes caution people not to get the influenza vaccine too early so that protection doesn’t wear off before flu season ends. Flu activity in the U.S. usually increases in early fall and peaks from December to February. Those who get a flu vaccine before November should have adequate protection against severe disease and death through spring. Although two doses may sound better than one, flu boosters are currently only recommended for young children. How long a flu shot lasts depends on individual immune systems, but the vaccine is usually effective for 6-8 months. Immunity wanes toward the end of our flu season. All viruses mutate, but influenza viruses do so rapidly. This perpetual viral drift necessitates the annual flu vaccine. Studies of second doses of flu vaccine in one season have shown no benefit for most adults. But among the very young, it’s a different story.