According to the Bloomberg School of Public Health at John Hopkins University, when most of a population is immune to an infectious disease, this provides indirect protection - or herd immunity (also called herd protection) - to those who are not immune to the disease.
Sida laga soo xigtay Iskuulka John Hopkins Bloomberg, Difaaca Dhirta waxaa lagu qeexi karaa marka dadka intiisa badani ay ka caabudaan cudur faafa, tani waxay siisaa difaac aan toos ahayn - ama difaac dadweyne (oo sidoo kale loo yaqaan difaaca xoolaha ama ilaalinta lo'da) - kuwa aan ka difaaci karin cudurka.