Facebook has deleted a post by President Donald Trump for violating its policy against spreading misinformation about the coronavirus.

The post in question featured a link to a Fox News video in which Trump says children are “virtually immune” to the virus.

Facebook said Wednesday that the “video includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misinformation.”

A few hours later, Twitter temporarily blocked the Trump campaign from tweeting from its account, until it removed a post with the same video. Trump’s account retweeted the video. The company said in a statement late Wednesday that the tweet violated its rules against COVID misinformation. When a tweet breaks its rules, Twitter asks users to remove the tweet in questions and bans them from posting anything else until they do.

Twitter has generally been quicker than Facebook in recent months to label posts from the president that violate its policies against misinformation and abuse.

This is not the first time that Facebook has removed a post from Trump, Facebook said, but it’s the first time it has done so because it was spreading misinformation about the coronavirus. The company has also labeled his posts.

Several studies suggest, but don’t prove, that children are less likely to become infected than adults and more likely to have only mild symptoms. But this is not the same as being “virtually immune” to the virus.

A CDC study involving 2,500 children published in April found that about 1 in 5 infected children were hospitalized versus 1 in 3 adults; three children died. The study lacks complete data on all the cases, but it also suggests that many infected children have no symptoms, which could allow them to spread the virus to others.