Three COVID-19 vaccines have now been authorized by the U.S. Food and Drug Administration (FDA). Vaccines developed by Pfizer (NYSE:PFE) and Moderna (NASDAQ:MRNA) have been available for months, while Johnson & Johnson (NYSE:JNJ) recently won emergency use authorization for its vaccine. 

It remains to be seen how effective these vaccines will be against new coronavirus variants that have emerged. The FDA recently provided new guidance related to these variants. In this Motley Fool Live video recorded on Feb. 24, 2021, Fool.com contributors Keith Speights and Brian Orelli discuss why this guidance is great news for the leading vaccine makers.

Keith Speights: To some more FDA news that came out. This week, the FDA issued new guidance related to the new coronavirus variants. Were there any specific things that jumped out to you in this new guidance that the FDA issued?

Brian Orelli: The big one that I saw was that the FDA is only going to require [laughs] immunogenicity.

Speights: Easy to say, right?

Orelli: I got a slight cold and [laughs] that third syllable is right where my clogged-up nose is. Looking at the amount of antibodies that the vaccine produces, they're only going to require antibodies studies for follow-on vaccines, so vaccines that are designed to protect against those variants.

This is much more like the flu vaccines, where they don't require them to run efficacy studies, so that the vaccines protect against the flu each and every year. Every time they change the vaccine, they only have to check for antibody levels and confirm that they can produce the antibody levels that are equivalent to what they showed when they actually did the original efficacy studies that show that the original vaccine protected against the flu.

There were some other guidance on testing companies. Some of the tests might not work against the new variance. You can think of a PCR tests, you separate the DNA strands and then your pro binds to those spots on the DNA wall. The DNA of the virus has changed in the new variants then if your pro binds right there then it won't, then it won't amplify the DNA and it won't show a positive against the variance.

Same thing with the protein test, that protein test using antibodies if your antibody doesn't bind to the spot. If your antibody binds to the spot where the variant has changed the protein level of the virus then you might get a false negative test that you were actually positive for the variant, but you don't test positive with these tests.

They are encouraging the test makers to obviously test for the variance, but also one way to avoid this is to have two antibodies bindings that halves the chance of having a variant, have a problem, or have more than one set of probes for the PCR test that would therefore amplify multiple areas of the genome and be able to catch the variance. There are some guidance also on therapeutics on how to test and run clinical trials for gaining authorization against the new variants.

Speights: There was an awful lot in this new guidance. I guess if there was one takeaway that I gathered from it, Brian was that it was generally good news for companies like Pfizer, Moderna, Novavax (NASDAQ:NVAX), ticker there is NVAX, these companies who have already announced plans to develop and test booster shots or maybe buy valent shots to target these new variants. It seems to be good news for those companies because the FDA is making the hurdles to jump more than a little lower.

Orelli: I would say a lot lower because you were talking about maybe a couple of a 100 people versus 30,000 people clinical trial and then the output is probably 28 days versus however long it takes for the people that get infected, and the infection rates are hopefully going to go down, which would mean that a follow-on clinical trial, the required efficacy, would take a heck of a lot longer than the original ones. I would go with a lot either.

Speights: But it's not really surprising to me that the FDA has come out with this. I think it's a prudent decision to do this.

Orelli: Yeah. Like I said originally, it's what you would see with flu vaccines and I think even other vaccines. They don't require efficacy studies too because the infection rates are so low that you can't really run efficacy studies on a lot of vaccines. The FDA pretty much have to do antibodies because that's all we can realistically do in a time-frame that would result in them the vaccine getting out in a reasonable time-frame.

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