Instagram banned Robert F. Kennedy Jr., son of former presidential candidate Robert F. Kennedy, from repeatedly posting misinformation about vaccine safety and COVID-19.

Kennedy Jr. has amassed a huge following on social media, where he frequently posts unproven claims about vaccines. “We removed this account for repeatedly sharing debunked claims about the coronavirus or vaccines,” a spokesperson for Facebook, which owns Instagram, said Thursday.

In a late January post, Kennedy Jr. described COVID vaccines being administered in the U.S. as posing a potential danger, despite studies on tens of thousands of people that found no serious side effects.

Kennedy Jr.’s Facebook page, which has more than 300,000 followers, and his Twitter account remained active as of Thursday morning.