from the two seroprevalence studies I found, ‘natural immunity’ is far smaller population that one would think - about 18% to 25% of the total population.
Only....other studies and reports have said that we are likely at 40% of population already have reached heard immunity/natural infection.
I’d say it is at least that.
Big whoop.
We’re all likely immune to many more viruses than we even know.
Herd immunity is part natural (prior infection with SARS) and part acquired (vaccine/infection). Pencil figures of recovered plus vaccinated gives us + 50% herd immunity. I went further. Going back to my figures, 180 million plus 25-50% of 120 million brings us above 70% net herd immunity once we add a variable for the subgroup.
But herd immunity wasn’t the focus of my post. Claims of so-called ‘natural’ immunity (prior SARS exposure/superimmune) and the risk ratio was. And as ‘herd’ immunity rises, so does the risk to those not protected - until the protection threshhold is reached.