[newacct583]

Herd immunity doesn't mean 100% exposure. It means a high enough incidence of antibodies such that the effective R0 goes lower than one, meaning that new outbreaks tend to shrink over time and not grow.

With most endemic viruses, antibody incidence is somewhere around 30-50% I believe, but I haven't seen any modelling for what covid is expected to do specifically.

[athrowaway3z]

If there are a high number of asymptomatic/mild cases that are to infectious to others this means it will have to be more. i've seen numbers between 70% and 80%. Thats why i took 1/4th to mean 80%