Originally posted by MarkJerling All that article says is that "sometimes" viruses mutate to be more deadly. Mostly, however, viruses become less deadly. We only need to look at something like Ebola which is super deadly and kills between 6 and 16 days after infection (usually). That's one of the reasons why Ebola has seldom managed to infect that many people. It's too good at killing. Then, on the other hand we have common cold viruses which are often corona viruses. Very good at replicating and spreading from person to person but seldom deadly. It's highly likely that Covid will, in due course, be just another common cold. Of course, it's early days (in terms of the evolution / mutation of a virus) and time will tell.
I'm not sure why COVID would need to become less deadly over time. The big things for a virus to continue are that it doesn't kill its host immediately (COVID probably kills around a half percent of people who get it and never immediately), that it is contagious enough that the host gives it to other people (this is where we have seen mutations make COVID quite a bit more infective), and that immunity to it wanes (COVID seems to be able to come back around for people every 12 months or so).
There are lots of viruses that have never changed to become less deadly -- polio, small pox, and viral hepatitis come to mind.
All pandemics come to an end, but typically they come to an end when the majority of people who are susceptible to an illness finally get over it and that can take multiple waves and years of time. The Antonine Plague took 15 years to burn itself out in the Roman Empire (AD 165-180) and the Plague of Cyprian lasted for 13 years (AD 249-262). The Bubonic Plague lasted from 1346 to 1353. I think the thing is with modern medical technology we can temper how severe an illness and come up with vaccinations for prevention and anti-viral agents for treating it. A couple of years seems like a long time, but in terms of pandemics, this one has actually been relatively mild -- primarily because of the different tools that have been brought to bear on it.