 This concept, called community immunity or herd immunity, is important to disease eradication, because it means that it is not necessary to inoculate 100% of the population—a goal that is often logistically very difficult—to achieve the desired result.If the number of susceptible individuals can be reduced to a sufficiently small number through vaccination, then the pathogen will eventually die off.When many hosts are vaccinated, especially simultaneously, the transmission of wild virus is blocked, and the virus is unable to find another susceptible individual to infect.