Listen Live

(INDIANAPOLIS) – Half to three-quarters of people receiving the coronavirus vaccine have had side effects for a day or two. But not getting any isn’t any reason to worry.

Feeling tired, achy or feverish the day after your shot means your body is delivering an immune response. But Community Health Network chief medical officer Ram Yeleti says about half the patients in the clinical trials for the vaccines didn’t get side effects. Whether they had side effects or not, all of them avoided serious illness, and most of them avoided the virus entirely.

In essence, the vaccine is practice for your immune system. Your body is learning to recognize the virus’s telltale protein so it can smack down the real thing when it sees it. Yeleti says the severity of your immune response to the vaccine has nothing to do with its reaction when it counts.

If you do avoid side effects, Yeleti says it may mean you were exposed to the virus before without knowing it. It could also just be your personal body chemistry, just like some people’s colds are worse than others’.

The side effects typically last only a day or two, though they can linger for three or four days. Yeleti says if you’re short of breath or still have pain or swelling for longer than that, it’s worth double-checking with your doctor. But he emphasizes there are no long-term effects from the vaccine, while there are hundreds of cases of long-term problems from the virus.