
Originally Posted by
Andalusian girls
viral mutations are selected for for the same reason anything else is, to replicate successfully. it is indeed to presume that will result in a less deadly virus as sometimes increasing severe symptoms will affect greater evolutionary fitness, while sometimes lessening severity of symptoms to improve host longevity will indeed increase fitness. it is a case by case basis. a general rule of thumb is that it is difficult for them to increase transmission rates while reducing lethality, and so they settle in a goldilocks ratio between the two. it is about finding the optimal mathematical equilibrium between host longevity and symptom severity.
in the specific case of Covid i would remain cautious as we have seen influenza and HIV viruses evolve over time to become resistant to the drugs and vaccines used to treat them. so while the severity of coronavirus symptoms may not increase, the ability of the virus to break through vaccination barriers may well increase, which would result in overall greater lethality, or rather something approaching a return to baseline lethality.