Donald Trump tested negative on consecutive days for Covid-19 and isn’t infectious, his doctor said today as the president traveled to Florida for his first campaign rally since he was hospitalized for the virus.

In a memo released by the White House, Sean Conley said the tests, along with guidelines from the U.S. Centers for Disease Control and Prevention, informed the conclusion that Trump doesn’t risk infecting others.

Conley did not say on which days Trump tested negative and the White House declined to comment when asked. Trump was tested using an antigen test, according to the doctor’s memo, which are considered to be less accurate than molecular tests.

Trump has come under criticism from his Democratic opponent, Joe Biden, and others for what they call a cavalier attitude about the spread of the coronavirus, which has killed more than 215,000 people in the U.S.

The president on Saturday made his first public appearance since testing positive, delivering a campaign-style speech before hundreds of people gathered closely together on the South Lawn of the White House. Conley had said in a memo Saturday night that Trump was no longer considered a transmission risk, but did not say whether the president had tested negative at the time.

In a call with supporters Sunday evening, Trump said he had “tested totally negative.”

Trump has forged ahead with plans to hold large events even though a number of top White House officials, senators and others in the president’s circle tested positive for the virus after a crowded Sept. 26 Rose Garden ceremony — where he announced his nomination of Amy Coney Barrett for the Supreme Court.

Tonight’s rally, along with three others planned this week, threatens to advance the spread of the coronavirus, warned Anthony Fauci, the top U.S. infectious disease expert, in an interview on CNN earlier today.

“Look at it purely in the context of public health,” Fauci said. “We know that that is asking for trouble when you do that. We’ve seen that when you have situations of congregant settings where there are a lot of people without masks, the data speak for themselves.”

Trump, who boarded Air Force One without wearing a mask, has asserted that his infection and subsequent recovery have made him “immune.” Fauci said it’s “likely” Trump is shielded from contracting the virus again for a certain period of time, but added there have been cases of people becoming re-infected.

“As the better part of caution, I think that would be appropriate to do that,” Fauci said when asked if he would recommend Trump and others wear masks and limit exposure to others even after they are no longer contagious.

Conley said Trump had tested negative on a rapid test made by Abbott Laboratories, which are commonly used in the White House but are not as sensitive as molecular screenings, including PCR tests. The Food and Drug Administration’s website says the antigen tests “are more likely to miss an active coronavirus infection compared to molecular tests.”

Yet Conley cited clinical and laboratory data and other tests “indicate a lack of detectable viral replication.” He wrote that “it’s important to note” that the Covid-19 test wasn’t used “in isolation for the determination of the president’s current negative status.”

The White House has faced pressure to release more information about the president’s condition. For example, Conley’s memo did not say when Trump last tested negative before he tested positive on Oct. 1, a key piece of information that can help determine whom he might have exposed.

The White House has cited patient privacy protections in declining to reveal the date of Trump’s last negative test.

Conley also did not say whether Trump is still taking medications. A bandage could be seen on one of the president’s hands at Joint Base Andrews before he departed for Florida.

The report on Trump’s negative test came one week after he was released from Walter Reed National Military Medical Center.