All of the following are true about the Herd Immunity for infectious diseases except:
Occurrence of clinical and subclinical infection in a community is responsible for herd immunity. Herd immunity; * It is the level of resistance of a community or group of people to a paicular disease. * Herd immunity provides an immunological barrier to the spread of disease in the human herd. * The epidemic wave declined with a build-up of herd immunity following natural infection. * It is neither possible nor necessary to achieve 100 per cent herd immunity in a population to halt an epidemic or control disease, as seen in SMALL POX eradication. * Herd immunity implies group protection beyond that afforded by the protection of immunized individuals. It provides an immunological barrier to the spread of disease in the human herd. * It may lead to elimination of the disease in due course (Eg. Poliomyelitis and Diphtheria). * In the case of tetanus, however, herd immunity does not protect the individual.
It refers to group protection beyond what is afforded by the protection of immunized individuals
It is likely to be more for infections that do not have a sub-clinical phase
It is affected by the presence and distribution of alternative animal hosts
In the case of tetanus it does not protect the individual