Individuals react to vaccines in different ways. The newly authorized coronavirus vaccines from Pfizer (NYSE:PFE) and Moderna (NASDAQ:MRNA) are no exception. The late-stage clinical studies of both vaccines revealed that some participants developed the same medical condition. In this Motley Fool Live video recorded on Dec. 16, 2020, Healthcare and Cannabis Bureau Chief Corinne Cardina and writer Keith Speights discuss whether Americans should be worried about a similar potential side effect of Pfizer's and Moderna's vaccines.

Corinne Cardina: Turning now to a couple of different headlines that have come out, there seems to be some concern about an adverse effect called Bell's palsy. Is this a side effect that could actually impact public opinion of this vaccine? What do we need to know about what this is and what it means?

Keith Speights: Yeah. I think Pfizer and everyone is hoping that it doesn't adversely impact public opinion because basically, what Bell's palsy is, Corinne, it's a weakness or paralysis in the muscles on one side of a person's face and it can be scary at first. Some people might think they're having a stroke because it's similar to one of the symptoms associated with a stroke where you have that paralysis on one side.

But it's actually a fairly benign condition. It can be inconvenient. My wife actually had it several years ago, and it was aggravating but it wasn't too problematic.

I tried to make things better, Corinne, although I think I was unsuccessful because I told her to look at the silver lining: It made it easier for her to show mixed emotions about things because she could smile with one-half of her face and frown with the other half. And she didn't think that was a great silver lining. But it's a bothersome, irritating type of condition but not something to worry about too much, and it usually resolves on its own over few weeks or months.

The reason why this has come up is that Bell's palsy occurred in participants in both of these studies, with Pfizer's and Moderna's study. I think in the Pfizer study there were four people, all of whom received the vaccine, who developed Bell's palsy. Then in Moderna's late-stage study, four people also develop Bell's palsy but three of those were in the vaccine group and one was in the placebo group.

Now, in both of these studies, there was no causal relationship established. There was no just firm, hard reason to think that the vaccines in either study actually caused Bell's palsy. But they can't rule that out, just not enough to completely rule it out.

If you had taken the exact same amount of people in these studies just off the street in a major city in the US, there would have actually been more people with Bell's palsy than we saw in these two studies. So that's, I think, a little comforting, that the rates that it occurred were actually a little less than what we've seen in the general population.

Personally, I think this is something that they are going to watch. I think you'll see the committee talk about it tomorrow. But I don't think it's anything that's going to prevent Moderna's vaccine from receiving emergency use authorization, and at this point, I don't think it's anything for Americans to worry about. The numbers just aren't there to make this a serious concern.

Corinne Cardina: Good. That is great insight. Thinking more about side effects, is there a risk of this information being spread as rare, adverse events are reported as the public starts getting vaccinated? I think the Bell's palsy headlines have been an example of this. Should companies be using their PR power to assure Americans that this is safe?

Keith Speights: Absolutely. I think it's a human tendency to focus on the negative even when the negative is overwhelmed by the positive. I think you're going to see that possibly on social media. I think some people are resistant to vaccines in general, and I think they're going to seize on any negative they can and possibly blow those negatives out of proportion.

So I think it's very important that companies, the government, state governments, local governments really try to get the word out to educate people on what are the things to truly be concerned about, what are the things that really aren't serious concern.

There are some things that can happen. There are very common adverse effects with these vaccines. You could develop fever, you could have fatigue, you could have pain or tenderness at the injection site. These are common types of things that people really should be prepared to expect and not be worried if you develop a fever after receiving the vaccine, it's common.

But it's not just common with the COVID vaccines, it's common with nearly any type of vaccine. So I think the public needs to be educated on these things.

You talked with Dr. Leo Nissola recently and that was one of his things. I think one of his biggest worries was that misinformation could be spread. I think it's really important that the true story get out there because we really want vaccination rates to be as high as possible to stop this thing, to end this pandemic.

Corinne Cardina: Absolutely. We will keep busting those myths as they come up here.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.