Herd immunity: In relation to COVID-19
Professor and Head, Department of Medical Biochemistry Govt.Medical College, Amritsar.
Review
World Journal of Biology Pharmacy and Health Sciences, 2020, 04(02), 049-055.
Article DOI: 10.30574/wjbphs.2020.4.2.0093
Publication history:
Received on 31 October 2020; revised on 08 November 2020; accepted on 11 November 2020
Abstract:
Herd immunity, also known as indirect protection, community immunity, or community protection, refers to the protection of susceptible individuals against an infection when a sufficiently large proportion of immune individuals exist in a population. In other words, herd immunity is the inability of infected individuals to propagate an epidemic outbreak due to lack of contact with sufficient numbers of susceptible individuals. It stems from the individual immunity that may be gained through natural infection or through vaccination. The term herd immunity was initially introduced more than a century ago. In the latter half of the 20th century, the use of the term became more prevalent with the expansion of immunization programs and the need for describing targets for immunization coverage, discussions on disease eradication, and cost-effectiveness analyses of vaccination programs. Eradication of smallpox and sustained reductions in disease incidence in adults and those who are not vaccinated following routine childhood immunization with conjugated Haemophilusinfluenzae type B and pneumococcal vaccines are successful examples of the effects of vaccine-induced herd immunity.
Keywords:
Susceptible Individuals; Vaccination; Natural Infection; Immunization; Herd Immunity
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Copyright © 2020 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0