The immunity of a group or community. The resistance of a group to invasion and spread of an infectious agent, based on the resistance to infection of a high proportion of individual members of the group. The resistance is a product of the number susceptible and the probability that those who are susceptible will come into contact with an infected person.
Specifically, the mechanism by which an infection may be eradicated from a population although some susceptibles still remain, because the remainder of the population is immune and thus transmission is reduced. More generally, the immunological status of a population of hosts and its effect on transmission rates.
immunity characteristics of a population. Depends both on immune function of individuals within the population and on the rate of transmission amongst individuals.
the phenomenon by which members of a community who are not immune to a disease are still protected from it provided sufficient numbers of people in that population are immune. When enough people are immune to a disease, it has little opportunity to find a nonimmune person and spread. Eventually that disease may be wiped out (e.g. smallpox). Herd immunity applies only to diseases that are caught from other people.
The phenomenon by which members of a community who are not immune to a disease are still protected from it provided sufficient numbers of people in that community are immune. This is because when enough people are immune to a certain disease, it has little opportunity to spread and so find a non-immune person. Herd immunity only applies to diseases that are caught from other people.
Having a large percentage of the population vaccinated in order to prevent the spread of certain infectious diseases. Even individuals not vaccinated (such as newborns and those with chronic illnesses) are offered some protection because the disease has little opportunity to spread within the community.
Resistance of a population to spread of an infectious organism due to the immunity of a high proportion of the population.
Herd immunity describes a type of immunity that occurs when the vaccination of the majority of the population (or herd) provides protection to un-vaccinated individuals.
