What is herd immunity, and is it a viable strategy to combat COVID-19?

Herd immunity is achieved when a virus stops circulating because a large segment of the population has already been infected or has been vaccinated against the virus. Public health officials estimate that 70 to 85% of the population will need to be vaccinated before herd immunity is achieved. Until then, getting vaccinated and the 3 Ws – wearing a mask indoors (beyond your home), watching your distance, and washing your hands – are the best tools we have to stop the spread of the virus.

Updated May 7, 2021