If the health misinformation currently spreading regarding coronavirus vaccines existed during the days of polio, it would have never been eradicated, Dr. Anthony Fauci, President Joe Biden’s chief medical adviser, said Saturday in an interview with CNN.

“We probably would still have polio in this country if we had the kind of false information that’s being spread now,” he said.

The statement comes as dangerous falsehoods about Covid-19 vaccines are swirling and as health experts warn of the more transmissible Delta variant’s increasing spread among unvaccinated Americans.

It also came days after President Joe Biden expressed his own visible frustration, saying social media that carry widely heard misinformation about vaccines are “killing people.”

“They’re killing people. The only pandemic we have is among the unvaccinated. And they’re killing people,” Biden told reporters at the White House.

The White House is turning up the pressure on social media companies to weed out what officials say is widely spread misinformation on coronavirus vaccinations.