| | | I can think how, theoretically, viruses over time could cause milder disease.
Assume that all mutations are random. Some are likely to make the virus worse, others will make it milder. Some people will get the nastier virus, others - the milder one.. BUT, over time, the population - one way or the other - will keep acquiring more familiarity with that virus. It would be developing a wider and deeper range of herd immunity. So, overall, clinically, the disease may have a tendency to become milder.
Once in a while, the bug may get a game changing mutation - and our immunity to that type of a virus may not do the trick. That’s when we get - or may get - a nasty killer epidemic, like the 1918 Flu. |
|
