WASHINGTON, D.C. — Twitter on Sunday deemed President Donald Trump’s declaration that he is now “immune” to the coronavirus and can’t spread it to others as “misleading and potentially harmful.”

On Sunday, the president tweeted he had received “a total and complete sign off from White House Doctors yesterday” and was no longer a threat to transmit the disease. 

Twitter tagged the post but did not remove it because it “determined that it may be in the public’s interest for the Tweet to remain accessible.”

Trump, who spoke at a White House event Saturday and will hold a rally Monday night in Sanford, Florida, made a similar comment in an interview with Fox News on Sunday, when he claimed his immunity could last “a lifetime." 

Twitter isn’t alone in thinking Trump’s comments are misleading. 

Some medical experts have been skeptical that Trump could be declared free of the risk of transmitting the virus so early in the course of his illness. Nor can he be completely assured of immunity following his illness.

Trump was referring to a memo released Saturday by the White House in which Navy Cmdr. Dr. Sean Conley said Trump met the Centers for Disease Control and Prevention criteria for safely discontinuing isolation and that by “currently recognized standards” he was no longer considered a transmission risk. The memo did not declare Trump had tested negative for the virus.

Dr. Albert Ko, an infectious disease specialist and department chairman at the Yale School of Public Health, said the White House appeared to be following CDC guidelines for when it is appropriate to end isolation after mild to moderate cases of COVID-19.

But Ko cautioned that those who have had severe cases of the diseases should isolate for 20 days, not just 10 days as Trump has done. He noted that Trump was treated with the steroid dexamethasone, which is normally reserved for patients with severe COVID-19.

Dr. Marc Lipsitch, an infectious disease expert at the Harvard School of Public Health, said the doctor’s letter does not provide enough information to be confident that Trump can no longer infect others. He said Trump’s use of steroids could prolong viral shedding so the CDC’s 10-day standard may not be enough.

As to immunity, while there’s evidence that reinfection is unlikely for at least three months even for those with a mild case of COVID-19, very few diseases leave people completely immune for life. Antibodies are only one piece of the body’s defenses, and they naturally wane over time.

“Certainly it’s presumptuous to say it’s a lifetime,” Ko said.