How does the virus know it needs to step up the mutations, and what direction to take?
It’s what viruses do.
Imagine a car trying to get out of a maze....keeps hitting walls (the “vax”)...it’s going to keep trying to ‘escape’, until no wall (un- “vax”d)....the more it releases/escapes, the less virulent it becomes, because it runs out of gas (weakens), eventually. That’s what viruses do.
The maze wall just refuels it.
(Best layman example that I can come up with, on short notice :)
I’m reminded of the study to prove evolution with regard to the dark and light colored moths on the dirty trees in England. Dark moths on dirty soot-covered trees up until the 1950’s or whenever.
Cleaned up their air and now the trees were their natural light gray and light gray moths appeared.
Well - they re-appeared. Prior to 1800 the light colored trees held light gray moths.
The moths didn’t change. Only their numbers changed. (Dark moths got eaten on light trees, etc.)
The original change of course was a mutation way back when, but after that it was just the numbers. Same goes I imagine with this virus.
In the early months in the Seattle area they were studying the details (dna I guess?) of the virus from the various people that had it. There were already numerous minor mutations and they estimated from the number/variety of mutations that the virus had been around for 4 to 6 months or something already.