Whilst we're covering this, let's just remind
@JPBB of the basis of heard immunity
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.
[1][2] In a population in which a large number of individuals are immune, chains of infection are likely to be disrupted, which stops or slows the spread of disease.
[3] The greater the proportion of individuals in a community who are immune, the smaller the probability that those who are not immune will come into contact with an infectious individual.
[1]
https://en.wikipedia.org/wiki/Herd_immunity