APhA Immunization Technician Practice Test

Herd immunity refers to the concept whereby a significant portion of a population becomes immune to a disease, typically through vaccination, which results in a decrease in the spread of that disease. When enough individuals are immune, either through vaccination or previous infections, the overall risk of transmission to those who are not immune is reduced. This is crucial for protecting vulnerable populations who may not be able to receive vaccines themselves, such as infants, the elderly, or those with certain medical conditions.

This concept is particularly important in controlling infectious diseases, as it can lead to the eventual eradication of the disease from the community or population, benefiting everyone. Vaccination plays a key role in achieving herd immunity, as it increases the proportion of immune individuals in the population without requiring everyone to be infected.