Definition from Wiktionary, the free dictionary
- (epidemiology) The protection given to a community against an epidemic of a contagious disease when a sufficient number of the population are immunised or otherwise develop immunity to it.
2006, Warren Levinson, Review of Medical Microbiology and Immunology, page 247:
- For herd immunity to occur, the vaccine must prevent transmission of the virus as well as prevent disease.
2009, Ray M. Merrill, Introduction to Epidemiology, page 65:
- Herd immunity is also viewed as the resistance a population has to the invasion and spread of an infectious disease.
- 2011, D. Caroline Coile, Pomeranians For Dummies, unnumbered page,
- Don't hedge your bets on herd immunity
- Some proponents of natural rearing condemn vaccinations; they prefer using homeopathic nosodes (medicine prepared from the diseased part or discharge of something, which supposedly works as well as vaccination). These people point to their dogs' good health as proof that nosodes work. However, their good fortune is probably the result of herd immunity, that is, as long as most dogs are vaccinated, the unvaccinated dogs rarely come in contact with the infectious agents.