The most interesting thing is the mutation rate. Sometime ago I explained it was mutating in various directions and given how rapid this was happening we would likely have more virulent versions. I also stated usually with more virulent versions we have less fatalities, however the reduced lethality is never guaranteed with mutation, neither is immunity for those infected by another version. This is why we have many different sets of vaccines in a flu shot and why herd immunity without vaccines cannot work. We are seeing this now. I love being right due to underpinning scientific knowledge.