Soon after the COVID-19 vaccine developed by Pfizer (NYSE:PFE) and BioNTech (NASDAQ:BNTX) began being given to Americans, reports surfaced about severe allergic reactions. Similar reports emerged after Moderna's (NASDAQ:MRNA) vaccine rolled out. In this Motley Fool Live video recorded on Dec. 23, 2020, Healthcare and Cannabis Bureau Chief Corinne Cardina and Fool.com writer Keith Speights talk about what investors need to know about COVID vaccines and these allergic reactions.

Corinne Cardina: We have already talked about the very rare allergic reactions that are being reported in certain recipients of the Pfizer-BioNTech vaccine. There has been news that the National Institutes of Health is planning a study in people with a history of allergic reactions to find out what component is resulting in these rare anaphylactic responses.

Keith, what do investors need to know about these side effects? Because while they are rare, they will probably continue to make headlines as they do happen because they're a deviation. A little bit of fearmongering that we need to counter as well. What should investors know?

Keith Speights: I think, Corinne, the most important thing for investors to understand here is that there's no reason to anticipate any disruption in the distribution of Pfizer's and BioNtech's vaccine from these rare cases. At this point, there is just absolutely no cause to think that's going to be the case.

Like you said, the NIH does plan to conduct a study. They're going to try to isolate exactly what component is causing these allergic reactions. It could take a while before they determine that. In the meantime, you are right. I think there could be some more headlines from people having adverse reactions. But again, these are very rare, and most people are getting the vaccine and not having any severe reactions whatsoever.

I think more than anything, it just underscores the importance of people who get the vaccine being monitored for a short period of time after receiving the vaccine. That's exactly what is happening now. Most people will be observed for around 15 minutes or so. Anyone who has a history of allergic reactions will be observed for a longer period, usually around 30 minutes or so. I think that's prudent, and I think that'll help avoid any major issues developed from this, but I think it's something to watch but nothing to be overly concerned about.

Cardina: Definitely. I'm going to put in the chat the CDC's guidance on the allergic reactions, who should get vaccinated, who should not get vaccinated, and the bottom line there is that talk to your doctor is the way to go.

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