Twitter boss Jack Dorsey recorded a podcast with a fitness personality who last month repeated a claim that "vaccines do indeed cause autism."
Host Ben Greenfield also told his followers not to trust internet watchdog Snopes in his Feb. 11 tweet, as previously reported by NBC.
On Tuesday, Greenfield wrote that he and the social media CEO chatted about "advanced stress mitigation tactics, extreme time-saving workouts, DIY cold tubs, hormesis, one meal a day," and other topics.
"Thanks Ben! Great conversation, and appreciate all you do to simplify the mountain of research focused on increasing one's health span! Grateful for you," Dorsey wrote in response.
Dorsey wasn't aware of Greenfield's views on vaccines, a Twitter spokesperson said via email, and his appearance on the podcast wasn't an endorsement of them. They didn't discuss vaccines during the podcast.
Twitter's health care policy restricts the promotion of "health claims about the cure, treatment, diagnosis or prevention of certain diseases and conditions."
Dorsey's appearing on the podcast came in the wake of Facebook taking steps to curb the spread of misinformation about vaccines and the World Health Organization declaring the anti-vax movement as one of the biggest threats to global health in 2019.
Last week, a Danish study of 657,461 children found no link between vaccines and autism.