Important: on the resurgence of SARS-CoV-2 in a place where herd immunity was already attained.

The authors lay out 4 reasons:

1) didn’t actually attain herd immunity
2) waning immunity
3) new strains evading immunity
4) much more transmissible strains https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00183-5/fulltext

Waning immunity is likely as a component. The immune system memory is just like real memory. I needs to be exercised w repetition - like studying for a test. A single event will not likely offer life long immunity.

2/x

My real concern is mutation that will evade, even If partial our immune responses to earlier versions of the virus or to vaccines being made (which are directed specifically towards mimicking earlier versions)

We have to act now on slowing spread in this case w/out immunity

3/x

We have tools we can use. Rapid antigen tests used twice weekly by a large fraction of people (say half) at home can keep get and maintain R below 1, stop outbreaks from emerging and slow them in their tracks where they are.

The tools are here. We just need to use them.

4/x