herd immunity

plural herd immunities

1. countableuncountableepidemiologyThe indirect protection against the spread of a contagious disease in a given population caused by the immunity of a significant proportion of the population to that particular disease; the immunity may have been obtained through having survived the infection or through vaccination.First known use early 20th c.

   Jews, long exposed to some diseases in the confined quarters of European ghettos, had developed herd immunities through a long process of natural selection.

   1994, Alan M. Kraut, “‘The Old Inquisition had Its Rack and Thumbscrews’: Immigrant Health and the American Workplace”, in Silent Travelers: Germs, Genes, and the “Immigrant Menace”, New York, N.Y.: Basic Books, →ISBN; Johns Hopkins Paperbacks edition, Baltimore, Md.; London: Johns Hopkins University Press, 1995, →ISBN, page 147

   5 more examples

   During the years that the herd was being replenished by purchase abortions were frequent, but that practice was discontinued, and the heifer calves born in the herd have been raised. [...] Thus a herd immunity seems to have developed as a result both of keeping the aborting cows and raising the calves.

   1917 January, Adolph Eichhorn, George M. Potter, “Prevention and Treatment”, in Contagious Abortion of Cattle (United States Department of Agriculture Farmers’ Bulletin; 790), Washington, D.C.: Government Printing Office, →OCLC, page 9

   The Spread of Bacterial Infection. The Problem of Herd-Immunity [title]. [...] Consideration of the results obtained over the last five years, [...] has led us to believe that the question of immunity as an attribute of a herd should be studied as a separate problem, closely related to, but in many ways distinct from, the problem of the immunity of an individual host.

   1923 May, W[illiam] W[hiteman] C[arlton] Topley, G[raham] S[elby] Wilson, “The Spread of Bacterial Infection. The Problem of Herd-Immunity.”, in The Journal of Hygiene, volume 21, number 3, London: Cambridge University Press, →DOI, →ISSN, →OCLC, →PMID, archived from the original on 02 Apr 2020, page 243

   It is likely that many animals in affected herds have developed an inapparent or nonclinical form of the disease because there have been no records of recurrence of the disease on the same farm—an indication that a herd immunity developed.

   1956, L. O. Mott, C. A. Manthei, “Miscellaneous Diseases of Cattle”, in Alfred Stefferud, editor, Yearbook of Agriculture 1956: Animal Diseases (United States Congress, House Document; no. 344), Washington, D.C.: The United States Government Printing Office, →OCLC, page 329, column 1

   The larger the number of immunised people in the community the less easy is the spread of disease from one person to another. [...] For the purpose of creating ‘herd immunity’, as this process is sometimes called, it is necessary to achieve 80 per cent immunisation of the community.

   1978, G. J. Ebrahim, Practical Mother and Child Health in Developing Countries (Macmillan Tropical Community Health Manuals), revised edition, London: The Macmillan Press, →ISBN; ELBS edition, London: English Language Book Society and Macmillan Education, 1980 (1982 printing), →ISBN, page 56

   The disease incidence appeared to have a cyclic course. After an outbreak, the disease and virus disappeared and the herd immunity gradually waned in the next 2 to 3 years. A new outbreak was the consequence of the reintroduction of transmissible gastroenteritis virus (TGEV).

   1995, Luis Enjuanes, Bernard A. M. Van der Zeijst, “Molecular Basis of Transmissible Gastroenteritis Virus Epidemiology”, in Stuart Siddell, editor, The Coronaviridae (The Viruses), New York, N.Y.: Plenum Press, →ISBN, page 337

   Synonyms: community immunity