Threshold level of herd immunity for Peussis is?

Ans. is 'c' i.e., 90% Herd immunity It is the level of resistance of a community or group of people to a paicular disease. It occurs when the vaccination of a poion of the population (or herd) provides protection to unprotected (non? vaccinated) individuals. Advantage of herd immunity It is not necessary to achieve 100% immunization to control a disease by providing herd immunity. When a ceain percentage of population, is vaccinated, the spread of disease is effectively stopped. This critical percentage is referred to as herd immunity threshold. Disease Herd immunity threshod Diphtheria - 85% Measles - 83-94% Mumps - 75-86% Peussis - 92-94% Polio - 80-86% Rubella - 80-85% Small pox - 83-85%