> Infectiousness and incubation period tend to be in tension with each other, many routes for virus shedding are symptoms (runny nose, cough, etc). Yeah, I agr

> Infectiousness and incubation period tend to be in tension with each other, many routes for virus shedding are symptoms (runny nose, cough, etc). Yeah, I agree, but I think this is somewhat orthogonal to my point—gain-of-function[0] studies seem to indicate that artificial passage is potentially selective enough to make this possible, even though these things are usually negatively correlated. > An extremely high death rate also does a better job of motivating responses, which while it isn't directly biological, has a significant impact on transmission. Absolutely. This was also likely why we saw such a huge and immediate response to SARS, which seemed roughly as (if not more) contagious than SARS-nCov-2, but had a CFR of around 10%. SK was also much less well-equipped to handle it then than it would be today (likely due to that exact reason). > I'm not so sure we really understand the full possibility space of infectious diseases though. Agreed, and this is mostly my worry. --- [0] For an even more terrifying gain-of-function study on H7N9, with higher virulence and mortality than the H5N1 study, the reference is: https://www.nature.com/articles/nature12392 https://www.nature.com/articles/nature12392 In this case, the virus was also able to be transmitted from ferret to ferret and appeared to have very high concentration in the lungs of ferrets (much more so than H5N1 which was scary enough), which are the usual model for transmission and replication in humans.