When a large percentage of a population is vaccinated against an infection, the causative microbe is unable to spread easily thr
ough that population. Because of this, susceptible individuals who cannot be vaccinated are protected to some extent by the community around them. This phenomenon is known as _____________. -herd immunity-subunit vaccination-passive immunization-adjuvant protection
Herd immunity refers to the resistance of a group of people against infection and the spread of a pathogen. It occurs when a high proportion of the members of that group are resistant against a particular pathogenic infection. When an earlier exposure or vaccination of a large proportion of individuals of a population does not allow the pathogen to spread among and infect the otherwise susceptible members of the population, the population is said to have acquired the herd immunity.
In the given example, vaccination of a large percentage of a population protected the susceptible individuals against a particular microbe. This represents an example of herd immunity.
