COVID variants

If we've learned anything about Covid it's that when we think we start to understand it the virus changes behavior, as if to spitefully prove us wrong. It's happening again. Now there are Omicron subvariants that can infect people who have not only had Covid but were infected with a slightly different Omicron variant. This pretty much buries the idea of herd immunity – something we were chasing early in the pandemic.
There’s considerable discussion about whether COVID vaccines are responsible for the barrage of variants that keep hitting us. Is selective pressure driving this – like with bacteria and antibiotics? Let's take a look.
Sometimes a picture or, in what follows, a video is worth so many words. Let’s consider the COVID variants; how could there possibly be so many so quickly. The answer, of course, lies in the work of Darwin.