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 as in 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 is 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…
Read More: npr.org