President Joe Biden on Wednesday said he does not “think about” former President Donald Trump after being asked about a refuted allegation his predecessor tested positive for COVID-19 a few days before their first debate last year, CNN reported.

Trump’s former chief of staff, Mark Meadows, wrote in his upcoming book about his time in the White House that the then-president initially tested positive for COVID-19 three days before his first debate of the 2020 presidential election against Biden, although a subsequent test taken before the debate gave a negative result.

When asked Wednesday about whether he thought Trump placed him at risk by getting on stage with him during that time, Biden responded: “I don’t think about the former president,” and left the room.

Dr. Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases, later told reporters he was not aware of a positive test for Trump before the first presidential debate.

“I certainly was not aware of his test positivity or negativity,” Fauci said, according to CNN.

When asked if he thought Trump had placed Biden at risk, Fauci replied: “I’m not going to specifically talk about who put who at risk. But I would say, as I’ve said, not only for an individual but for everybody, that if you test positive, you should be quarantining yourself.”

Trump denied Meadows’ account in a statement Wednesday, saying, “The story of me having COVID prior to, or during, the first debate is Fake News. In fact, a test revealed that I did not have COVID prior to the debate.”

The former president said in October of that year that he could not remember if he had been tested for COVID-19 before the first presidential debate.