What is herd immunity? May 14 2021, 15:27 ET SINCE the start of the coronavirus pandemic, the term herd immunity has been tossed around the world in academic and scientific circles. The term has been widely used in the sense of hope as the world continues its fight to end the coronavirus pandemic. 7 The term herd immunity has recently been used in the sense of hope as the world continues its fight to end the coronavirus pandemicCredit: Getty What is herd immunity? Herd immunity refers to where enough people in a population have immunity to infection to be able to effectively stop that disease from spreading.