Herd Immunity Provides Important Protection Against Disease

November 3,2017

No, this is not something that should be discussed with your veterinarian. Herd immunity, which is also called community immunity, population immunity, herd effect and social immunity, is the terminology used to define the indirect protection from infectious disease that comes from a large percentage of a population receiving immunization. The purpose of vaccines is to save lives and reduce severity of contagious diseases that could otherwise result in an outbreak. Vaccines work by triggering an individual's body to produce antibodies to fight a disease without that person actually having the disease.

Passive immunity occurs when a vaccinated person comes in contact with a contagious disease and his or her body immediately responds by producing the antibodies needed to fight off the disease. Herd immunity provides an indirect protection from infection for individuals who are not immune. For example, the entire population of an isolated community can be protected from a measles outbreak, if 90 to 95% of the population has been vaccinated. The theory of herd immunity has been used for generations to protect large populations from experiencing an outbreak of certain bacterial and viral infections.

If an unvaccinated child is exposed to a disease, there is a danger that their body may not be strong enough to fight the disease. According to the Institute for New Economic Thinking at the Oxford Martin School (Oxford University), the health conditions of our ancestors in 1800 were such that 43% of newborns died before age five. By 1960, child mortality rates were still 18.5% meaning that around one in five children born in that year did not reach adulthood. Supporting the concept of herd immunity, we have seen a rapid decline of child mortality, which in 2015 was down to 4.3%.

Since an immunized majority provides protection for the entire population, anyone susceptible to a pathogen is unlikely to ever be exposed to the contagious disease. Despite the scientific evidence supporting the safety and necessity of vaccinations, some families continue to distrust the importance inoculations. A trend that has many doctors worried that their refusal could put other patients at unnecessary risks. Children with complex diseases or compromised immune systems rely totally on herd immunity for protection. If you've hesitated to have your children vaccinated, schedule an appointment at either PrimeMED location to discuss your concerns with our board-certified physician.