Ah, fair play. I thought you were purveying the common misconception that a virus which kills its host is less effective at finding new hosts than one which doe

Ah, fair play. I thought you were purveying the common misconception that a virus which kills its host is less effective at finding new hosts than one which doesn't, but this is unfortunately not the case. Alas, your actual theory doesn't really hold up either. It's tough to remember the mood thirteen months ago, but China was under a real lockdown, we were seeing videos of people passing out in the street (funny, that doesn't seem to have kept happening?) and apartment building being welded shut, there were reports circulating of nitrogen-rich plumes of smoke in Wuhan which might be mass incineration of bodies: people were really scared. America even closed the border to China, against the explicit policy of WHO, but didn't shut down travel from Europe fast enough; also, the current consensus is that SARS-2 was circulating in the US by mid-December 2019 at the latest, so it's unclear how much benefit a total travel ban would have provided. But, no: SARS-1 doesn't become highly infectious until after symptoms set in, that was what saved us last time. It does seem to be true that countries which experienced the SARS epidemic first-hand developed what we might call institutional antibodies, and were quick to impose various controls (especially contact tracing) which were more effective at controlling COVID-19. But COVID-19 has a long period of presymptomatic infectivity, it sheds for almost a week during which the patient feels fine. If SARS presented with that etiology, there is a good chance that it would have swept the planet, killing, potentially, hundreds of millions of people. Just dumb luck.