Quoted: While some estimates suggest communities can reach herd immunity when around 70 percent of the population is vaccinated, Dr. Matt Anderson, UW Health senior medical director of primary care, explains it isn’t an on-off switch.
“It’s really hard to say at what point we’ll reach it as though it’s a critical threshold,” Anderson said. “It’s more of a gradual decline in the case rates that we’ll see as we have more and more people being immune, and the best immunity is through vaccinations.”
Ajay Sethi is a professor of population health sciences at the University of Wisconsin-Madison and is faculty director of Master of Public Health Program. He said it will be clear that communities have reached herd immunity when there are no longer outbreaks of COVID-19 despite people returning to pre-pandemic daily activities like going maskless to concerts, sporting events, movie theaters, or restaurants without social distancing.
“In order for this to happen, most everyone will need to have protective immunity from either vaccination or past infection, but immunity from the latter may not be as long-lasting or durable,” he said.