I have a question for anyone who has a serious level of knowledge on virus evolution: As viruses evolve over time is there any correlation to severity - do they have trade offs as they evolve? I am hoping that it would be some kind of trade off that the virus makes in that it can spread more easily but not be as severe (I understand that it is unlikely nature requires a trade-off). I ask as my concern is that while t…
Sort of. Sometimes. Viruses evolve according to evolutionary pressures. I'm surprised we don't see Covid mutations that invalidate PCR tests - perhaps it's too soon, or even, who knows, maybe they are there and we don't know? The common trope is that if the virus is too deadly, then it doesn't have a chance to find new hosts. This is kind-of what happened to "SARS-1" - it tended to kill its hosts before they could pa…
PCR tests for RNA or DNA, that's not something a mutation can change. I don't know for Covid, but usually a PCR test targets something fundamental & stable. That might need to be updated with new variants.