YouTube is taking down several video channels associated with high-profile anti-vaccine activists including Joseph Mercola and Robert F. Kennedy Jr., who experts say are partially responsible for helping seed the skepticism that’s contributed to slowing vaccination rates across the country.

As part of a new set of policies aimed at cutting down on anti-vaccine content on the Google-owned site, YouTube will ban any videos that claim that commonly used vaccines approved by health authorities are ineffective or dangerous. The company previously blocked videos that made those claims about coronavirus vaccines, but not ones for other vaccines like those for measles or chickenpox…

YouTube didn’t act sooner because it was focusing on misinformation specifically about coronavirus vaccines, said Matt Halprin, YouTube’s vice president of global trust and safety. When it noticed that incorrect claims about other vaccines were contributing to fears about the coronavirus vaccines, it expanded the ban.

“Developing robust policies takes time,” Halprin said. “We wanted to launch a policy that is comprehensive, enforceable with consistency and adequately addresses the challenge.”