Coronavirus, (1039) Herds Immunity and COVID 19 (2)

18 October, 2020

Dear HIFA colleagues, Good to see discussion of competing views re C19.Can we get some competing hypotheses (and maybe supporting evidence) about why there are such different percentages of excess deaths across OECD countries (eg, Finland and Germany vs. UK or Italy)? Emphasis on hypotheses, let's stop short of assertions until evidence pushes hard.How about some competing hypotheses to explain low impact on South Asia and Africa? Competing hypotheses, please. The issue of herd immunity is relevant. David Egilman's assertion that herd immunity is irrelevant for communicable viral diseases seems to me to miss some things. For example, herd immunity seems to have a lot to do with changes in flu viruses from year to year: "Seasonal influenza virus strains are continually changing in response to the existing herd immunity in the human population" (see: Palese and Wang 2011 at:  https://mbio.asm.org/content/2/5/e00150-11. Does anyone know what herd immunity might look like for C19? Would C19 then behave like the other corona viruses year after year? Mostly mild colds?Regards,

David

HIFA Profile: David Gisselquist is an independent consultant in the United States and has a professional interest in nosocomial risks and transmission of HIV in Africa, agricultural development and agricultural inputs regulation, environment. Email address: david_gisselquist@yahoo.com