Public Health

Half of Americans have now received at least one dose of a Covid-19 vaccine, and with children ages 12 to 15 now eligible for immunizations, the United States appears to be getting the coronavirus pandemic under control. But despite the tremendous progress, it’s still not clear that the nation will ever truly reach the herd immunity threshold — the point at which enough people in a population are immune to a pathogen to limit its spread.

More important, we may not need to achieve that goal in order to escape the pandemic.