White House chief medical adviser Anthony Fauci said Sunday that unvaccinated Americans need to shift their focus from “concerns about personal liberty” to combat the “common enemy” of the COVID-19 pandemic.

“You have to get the overwhelming proportion of people vaccinated, but you also have to do mitigation, and that gets to the controversial issue of mask wearing, and the mandating of things. Mandating vaccines, for example, for teachers and … personnel in the school,” Fauci said during an interview on CBS’s “Face the Nation.”

Fauci went on to say that, while vaccinated individuals have become infected with the coronavirus, the unvaccinated are the ones with more severe cases. He also took the stance that personal liberties should be put on the back burner in favor of mitigating the spread of the virus.

“It’s the unvaccinated that are doing that, so we have a lot of tasks,” Fauci said. “We’ve got to do mitigation. Put aside all of these issues of concern about liberties and personal liberties and realize we have a common enemy and that common enemy is the virus. And we really have to go together to get on top of this. Otherwise, we’re going to continue to suffer as we’re seeing right now.”

When asked if people eligible for a third booster shot of a COVID-19 vaccine should receive a Moderna jab, regardless of their initials doses, in reference to a recent a study that found the Moderna vaccine is more effective than Pfizer at stopping the new highly infectious delta variant, Fauci was skeptical.

“First of all, it’s a preprint study, It hasn’t been fully peer-reviewed and I don’t doubt what they’re seeing, but there are a lot of confounding variables,” he said.