One of the first known references to #HerdImmunity came amid an outbreak of “contagious abortions” (#brucellosis) in livestock in the early 20th century.
Read more at:
https://www.washingtonpost.com/history/2021/05/18/herd-immunity-history-cows/
How ‘contagious abortion’ in cows led to one of the first known references to herd immunity