Twitter disabled some sharing options on a tweet from President Trump on Sunday, and labeled it for violating its rules against spreading coronavirus misinformation. In the tweet, the president said he had “A total and complete sign off from White House Doctors yesterday. That means I can’t get it (immune) and can’t give it. Very nice to know!!”

Even with the label, the tweet is still available for those who click through the warning, in keeping with Twitter’s position that keeping tweets from elected officials visible is in the public interest. And attempts to share the tweet bring up an alert that reads “We try to prevent a Tweet like this that otherwise breaks the Twitter Rules from reaching more people.” The labeled tweet is still able to be quote-tweeted, however.

The president’s assertion that he’s now “immune” since he already contracted the coronavirus is likely what got the tweet flagged, since there have been documented cases of coronavirus patients becoming reinfected. A man in Nevada had COVID-19 in March then recovered in April only to fall ill again in May. The first documented case of a coronavirus reinfection occurred in Hong Kong, where the patient showed no symptoms the second time around.

The Centers for Disease Control and Prevention website has limited information about reinfections, but says “a person who has had and recovered from COVID-19 may have low levels of virus in their bodies for up to 3 months after diagnosis,” and that the science “does not imply a person is immune to reinfection” from the virus.

A Twitter spokesperson said it was not the first time the platform has disabled sharing on a tweet by the president containing incorrect information. In addition to updating its policies last month that it would label or remove tweets with false information about election rigging and results, Twitter also said it would label posts from candidates prematurely declaring victory. And Twitter said back in March that it was taking a “zero-tolerance approach” to coronavirus misinformation on its platform.

Last week’s updates further tightened the rules around spreading misinformation, and encouraged people to quote-tweet and “add their own commentary” to tweets before retweeting someone. The update also included plans to flag or remove tweets meant to incite interference in the election or election results, and tweets from political figures with more than 100,000 followers — which includes President Trump — labeled as “misleading” are now more difficult to access

Twitter has labeled several of Trump’s tweets for violating its policy on manipulated media and civic and election integrity for tweeting falsehoods about mail-in voting.

The White House did not immediately reply to a request for comment Sunday.