Filed Under:

Can You Get A Flu Shot And Still Get The Flu?

Play associated audio

This year's flu season started about a month early, prompting federal health officials to warn it could be one of the worst in years. They're urging everyone to get their flu shots.

But like every flu season, there are lots of reports of people complaining that they got their shot but still got the flu. What's up with that?

Well, as Michael Jhung of the Centers for Disease Control and Prevention explains, there are lots of possible reasons.

The first is that while the flu vaccine is the best way to protect against the flu, it's far from perfect. In fact, the vaccine is only about 60 percent effective. So some people can get the flu even though they were vaccinated because the shot just didn't work for them.

The vaccine, for example, tends to work less well in the elderly. That's a big problem, since the elderly are among those at greatest risk for serious complications from the flu.

Another reason is that it takes about two weeks for the vaccine's protection to kick in. So if someone gets exposed to the flu in that time between when he gets the vaccine and when his immune system has responded sufficiently, he could still get sick.

Also, it's always possible that someone could get exposed to a strain of the flu virus that's not covered by the vaccine. This year's vaccine, though, looks like it should work pretty well — the flu virus strains in the vaccine appear to be a very good match for the most common flu strains that are circulating this year.

The last reason is that someone might get exposed to another kind of virus that causes symptoms that are very similar to the flu. There are lots of other viruses out there that can cause respiratory illnesses, such as adenoviruses, parainfluenza viruses and respiratory syncytial virus.

Copyright 2013 National Public Radio. To see more, visit http://www.npr.org/.

NPR

With 'Formation,' Beyoncé Lights Up The Internet. Here's What People Are Saying

The singer's new music video quickly drew commentary of all kinds — on its references to being black in America, Hurricane Katrina and Black Lives Matter.
NPR

Calif. Restaurant Gives Diners — And Sea Lions — An Ocean View

The Marine Room is a restaurant right on the beach. When the tide is high, waves hit the windows, and bring in unexpected visitors.
NPR

What Do Sanders And Trump Have In Common? More Than You Think

The two hottest candidates heading into Tuesday's New Hampshire primary: Donald Trump and Bernie Sanders. On the face of it, the candidates and their messages couldn't be more different.
NPR

Super Bowl 50 Tightens Cybersecurity

This year's Super Bowl will be held in the most technologically advanced stadium in the world. FBI special agent John Lightfoot talks to NPR's Rachel Martin about the threat of cyber attacks.

Leave a Comment

Help keep the conversation civil. Please refer to our Terms of Use and Code of Conduct before posting your comments.