Originally posted by GUB Sars never broke loose like this did it.
Ironically, the original SARS was too virulent to spread -- it made almost everyone so sick that it was easy to spot and to contain.
At some level, COVID-19 really is a worst-case pandemic virus because many people can catch it and spread it without any serious symptoms and yet the virus also seriously sickens and kills enough people to be a dangerous health problem. Thus, unlike SARS, COVID-19 can fly under the radar (unless the radar is really good which requires high-frequency testing of a lot of people all the time).
There's a Goldilocks principle at work here:
* SARS is "too strong" to spread far and wide and maximize the virus population.
* The common cold (also caused by coronaviruses) is "too weak" to spread far and wide and maximize the virus population.
* COVID-19 is "just right" for maximizing the virus population (which maximizes human misery).