Analysis of herd immunity using the Sorites Paradox

[See supplemental article Covid-19, herd immunity and common sense]

TL;DR

  • The concept of "Herd immunity" fails elementary rational analysis.
  • A "herd" cannot be scientifically defined. A "herd" remains an irreducibly vague concept.
  • Ipso facto, "herd immunity" is not an identifiable, valid phenomena.
  • Population percentage deaths and illnesses correlate with psycho-social-enviro factors.

When the subject of vaccination1 is discussed within a group (e.g. online forum), and there are some within that group who are pro-vaccination, almost invariably they will at some point raise the issue of herd immunity.

First let's clarify what is meant by "herd immunity"2
. From Wikipedia3 this:

"Herd immunity (also called herd effect, community immunity, population immunity, or social immunity) is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, thereby providing a measure of protection for individuals who are not immune".

There are, it seems to me, a number of aspects to this subject that need clarification: