How serious are the side effects for the COVID vaccine?

Infectious disease experts are calling Pfizer's vaccine results an A plus and a grand slam. New data released by the FDA today showed it worked very well, regardless of race, age, or weight.

The trials also showed no serious adverse effects. But some people did experience minor symptoms. What do we know about the vaccine's side effects? Good question. Heather Brown tells us why it might be a good idea to plan a day off after you get the shots.

If you were to get the vaccine, would you expect any side effects?

Perhaps.

The body aches.

Or a fever.

Fatigue.

It's tough to say because we don't know. Everybody side effects would be different.

According to Pfizer's data, 66% of participants experienced pain at the injection site after the second dose; 60% fatigue. 52% had headaches, 35% chills, and 2% vomited.

That's a little higher than for most vaccines. That probably is not a bad thing. That means you're getting good immunity.

Dr. Frank Rhame is an infectious disease specialist at Allina.

Just to be clear, if you're not feeling so great after you get the vaccine, that doesn't mean you have a mild case of COVID or a weakened case of the virus.

No. No, you can't get COVID from this, for sure.

It's your body's immune response mounting to that protein that the mRNA is coding for.

That's the way it was with the measles vaccine. That's why it was the oral polio vaccine. These are live attenuated weakened viruses. That's old stuff. We don't do that anymore.

On average, the Pfizer vaccine side effects lasted for a day, similar to what these trial participants reported.

I was shivering, and my teeth were chattering.

I had some soreness in my right-- my left arm, which is my vaccine arm.

It only lasted that one day, and then it was gone the next day after that.

Right now, the trials can tell us what the short-term side effects might be. But could there be long-term side effects to this COVID vaccine?

Absolutely. That's why we need people to stay in our trials for two years to find that out.

He said it's rare, but it's happened. In 1955, 1 in 100,000 reported paralysis after getting the polio vaccine. In 1976, 1 in 100,000 reported a nerve disease after the swine flu vaccine. Both vaccines were stopped.

Every one of those side effects occurred in the first six weeks after vaccination.

Long-term effects we're not going to know. But there are usually very few long-term effects.

Well, precedent would suggests that we're not going to see late problems.

So experts say it's important to understand--

If my trade-off is a headache or a fever--

--the vaccine is a far better choice than the illness.

I've had COVID. So I don't want to get it again.

Heather Brown, WCCO 4 News.