A virus may become less deadly. There is no guarantee. It depends on what evolutionary options are available and what pressures are selecting mutations. Pre-

A virus may become less deadly. There is no guarantee. It depends on what evolutionary options are available and what pressures are selecting mutations. Pre-symptomatic infectiousness has about the same selection pressure as low mortality rate IMO. Low risk viruses circulate well because people don’t care about transmission very much. High risk infections cause people to take precaution and thus eliminates those stains. SARS-COV-1 and MERS were that way. But pre-symptomatic infectiousness (SARS-COV-2) makes this calculus immaterial for most people; they transmit it without knowledge. This reduces the pressure on high mortality / morbidity strains / variants.