The resistance of a population to an attack by a disease to which a large proportion of the members of the group are immune is referred to as

Herd Immunity

Explanation:

Herd immunity is referred to as the resistance of a population to the spread of a contagious infectious disease to which a large number of the population are immune to the disease, these are achieved through immunization often called vaccination.

Vaccination program have been successful against many infectious diseases that once killed, crippled, or incapacitated large number of members of a population.

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