How to Build Behavioral Herd Immunity Against COVID-19 | RealClearScience

Herd immunity is a concept that comes from the field of zoology. It refers to the ability of a population of animals to resist infection by a pathogen — such as a virus — because a sufficiently large number of individuals within the population have humoural immunity on an individual level. Humoural immunity is the ability of the immune system to form antibodies against a specific infectious agent.

With herd immunity, transmissibility in a population is dramatically reduced via immunological mechanisms. This is the theory behind vaccines, which boost specific immunity within (ideally) a very large proportion of the population, such that a transmissible disease never gains a foothold.
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