Girdler-Brown, B.V. (Brendan)Murray, J.2021-11-092021-11-092020-08Girdler-Brown, BV & Murray, J 2020, 'Epidemic reproduction numbers and herd immunity', South African Medical Journal, vol. 4, no. 2, pp. 59-64.0256-9574 (print)2078-5135 (online)10.7196/SHS.2020. v4.i2.121http://hdl.handle.net/2263/82595In this educational article, we explore the meanings and the applications of the reproductive numbers, namely the basic reproductive number R0, and the effective reproductive number R. We also give examples of how these numbers may be affected by the values of β, κ and D, and we go on to explore the relationship of the R0 value to the concept of herd immunity. Finally, we discuss how these concepts may contribute to the control of infectious disease outbreaks.en© 2020 Health & Medical Publishing Group. This journal is protected by a Creative Commons Attribution - NonCommercial Works License (CC BY-NC 4.0).Reproductive numbersR0ValueHerd immunityArticle