Herd Immunity. Even non-science types have a vague idea of what it means. Most of us realize it refers to the protection from viral infections when a large percentage of the population obtains immunity to it. A large immune population helps prevent the spread of the virus. But how is that immunity achieved?
According to the World Health Organization (WHO), the methods to obtain herd immunity used to be found on this web page. The page, titled Coronavirus Disease (Covid-19): Serology and dated 9 June, 2020, can be found on the Web Archive (Wayback Machine): https://web.archive.org/web/20201101161006/https://www.who.int/news-room/q-a-detail/coronavirus-disease-covid-19-serology
According to the WHO, on June 9, 2020, herd immunity was defined as
“the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.” (all emphasis mine)
An accurate and accepted definition, one that concurs with almost every other explanation on the internet and in every basic biology book I’ve ever seen.
