It is likely it will mutate to something less dangerous as Spanish flu did after 13 months. There was a lot of moving around in 1918/19 because of WW1. Didn' t we have 3 million people in France that were transported back in 1 month? Spanish Flu spread fast in crowded areas - 12,000 died in 5 weeks in the City of Philadelphia in October 1918 when a group of sailors arrived from New York that must have needed a high R number. If you look at the infection and death rates in 1918/19 and 2020/21 the UK trend line looks similar, with high rates in May 1918 and then a second bigger wave in November 1918 and a smaller third wave in May 1919 (which I hope we will avoid through vaccines).
We lived a 100 years with polio without any lock downs. It was horrible, you probably had 1 in 100,000 chance of getting it if you went in a Public swimming pool in the 1950s (as poor Ian Drury did) . TB killed hundreds every year on Teesside in the 1950s and even 1960s. Poole hospital at Nunthorpe was a TB hospital. My grandad died there in 1958 in his early 50s and my mum said it was packed. We have to live with some very low level risk.
I would vaccinate everyone eventually as the young can still get ill with it and spread it. We have to create a barren environment for CV19 without lock down.
Ref requiring 90/95% herd immunity - its hard to believe only 5% to 10% are naturally immune - in the worst plagues of the middle ages - at least 35% were naturally immune.
