I've heard that "herd immunity" is part of why getting kids vaccinated is important. But lately I see news about how herd immunity could be a risky way to try to deal with the COVID-19 pandemic. So is herd immunity a good thing or not?
– Corrine
Herd immunity is the idea that when many people are immune to a contagious infection, usually by getting a vaccine, it's harder for that infection to spread in a community. Vaccines teach the body to recognize and fight germs so we can't get sick from them in the future. This helps us become immune to infections. Otherwise, people become immune only after recovering from an infection that they caught from someone else. To achieve herd immunity this way, many people would get sick or even die in the process.
Herd immunity (also called community immunity) protects people who are not immune to a disease, such as those who:
When about 7 or 8 out of 10 people are immune to an infection in a community, their whole community is usually protected — not just those who are immune. Diseases that are very contagious, like measles, might need almost everyone to be immune.
It has been suggested that people with a lower risk of severe COVID-19 infection be allowed to become immune by catching it.
But because COVID-19 is a new disease, most health experts don't yet know if herd immunity to coronavirus is possible, for a few reasons:
So yes, herd immunity is a good thing, but it must happen safely. Until there is a vaccine against coronavirus, health experts worldwide say that the best way to prevent its spread is to:
Reviewed by: Elana Pearl Ben-Joseph, MD
Date Reviewed: 26-10-2020