"that virulence is not subject to the same selective factors" It's a matter of degree, not a binary thing. You can't be 100% sure of anything, but as long as p

"that virulence is not subject to the same selective factors" It's a matter of degree, not a binary thing. You can't be 100% sure of anything, but as long as people are aware of something and act accordingly, there will be selection pressure. Reduced social contact has an effect regardless of whether specific carriers are identified.