Both Pfizer (PFE +1.50%) and Merck (MRK 0.96%) have won U.S. approvals for their respective COVID-19 pills. In this Motley Fool Live video recorded on Jan. 5, Fool contributors Keith Speights and Brian Orelli respond to a viewer's question about how these pills work.
Keith Speights: We have Ya'ir Brings the Light: "It's a good morning, Brian and Keith. I'm curious and the mechanisms by which to COVID pills work. Are they too based on mRNA?"
Brian Orelli: Yeah, so they're not based on mRNA. There are basically two drugs right now that have authorizations by the FDA. There's Merck's drug. Merck's drug is basically a nucleotide. It gets incorporated into the RNA, which is the viral RNA. There's DNA viruses and RNA viruses. Coronavirus is an RNA virus, so it makes RNA and then it goes into the patient cells as an RNA and then it makes more RNA and packages all up and makes more viruses and then explodes the cell and those viruses go and infect more cells, and that's how viruses work.
Then Merck's drug, it gets incorporated into the RNA by mixed mutations. It gets incorporated, but it's the wrong thing that's getting incorporated. The idea is just to mutate the heck out of the virus and then when it develops enough mutations, now can no longer replicate because it can synthesize it, the machinery that it needs to replicate.
Pfizer's drug is completely different, it inhibits a kinase, I think, or something. It's inhibiting one of the proteins of the virus, and so that's how it's able to inhibit the virus. It's inhibiting the ability of the virus to make more of itself.
Speights: Yeah, my understanding, Brian, is neither of those COVID pills target the spike protein on the surface or anything like that. They should be effective even with new variants emerging, right?
Orelli: Right. In theory, those areas should be conserved in the virus, so that should help keep them working even with different variants.
