English Dictionary

herd immunity

/ˈhəːd ɪˈmjuːnɪti/

noun

(epidemiology) The indirect protection against the spread of a contagious disease in a given population caused by the immunity of a significant proportion of the population to that particular disease; the immunity may have been obtained through having survived the infection or through vaccination.

Herd immunity is achieved when a large portion of the population becomes immune to a disease.

意味（1）

(epidemiology) The indirect protection against the spread of a contagious disease in a given population caused by the immunity of a significant proportion of the population to that particular disease; the immunity may have been obtained through having survived the infection or through vaccination.

During the years that the herd was being replenished by purchase abortions were frequent, but that practice was discontinued, and the heifer calves born in the herd have been raised. … Thus a herd immunity seems to have developed as a result both of keeping the aborting cows and raising the calves.