Also called "group immunity" or "collective immunity" is a term proposed by microbiologists Graham Selby Wilson and William Whiteman Carlton Topley in 1923, suggesting that in an epidemic case the study of individual immunity should be separated from that of the collective immunity, since when a sufficient amount of resistant population appears these form a barrier to the virus that does not reach those who are not vaccinated or lack defenses. The number is a statistical calculation (usually obtained past the epidemic and serves for the next) that takes into account too many variables to anticipate the sufficient percentage that can serve as indirect protection, especially in new diseases. The original English name is herd immunity. See R 8320; r0 , R 8337; re, pandemic, covid-19.
HERD IMMUNITY . Concept used by epidemiologists, virologists, infectologists and other specialists to explain the phenomenon of immudity of a social group in that it achieves a critical mass of vaccinated and immunized. From a certain point, say 80% of vaccines no spread of contagion as the virus or bacteria does not find enough means to maintain the level of infected and the contagion disappears even if there is a rest of the group (herd) that does not have the Antibodies.
