Why You Need the Flu Shot Every Year - New York Times

New York Times

Why You Need the Flu Shot Every Year New York Times Most people know: If you got a flu shot this year, next year you'll need it again. This is because the virus changes, usually rendering the previous year's vaccine partly or totally useless. And it's no secret that the flu vaccine's effectiveness falls ... and more »

from Health - Google News http://ift.tt/2l2XjBY