Apology needed for entire population, page-18

Not the best chosen name in hindsight, but the concept was originally developed by veterinary scientists [1]. A better name is population immunity.

With highly infectious diseases like measles or Covid you need to vaccinate 90% of the population to reach herd immunity and prevent the disease spreading. This is why before the government gave up there was so much pressure or ‘coercion’ put on getting everyone vaccinated. Unfortunately, the days when you could explain to everyone this are long behind us and it is now impossible to convince a sizeable chunk of the population to do anything.

1. https://en.wikipedia.org/wiki/Herd_immunity