In an interview with the Wall Street Journal, the billionaire recalled a recent dinner he had with Trump, incoming White House chief of staff Susie Wiles, and a staffer for Gates.

The conversation was wide ranging, and one of the topics was HIV, according to Gates, who said his Gates Foundation is working on a cure for the disease.

“He, in the COVID days, accelerated the vaccine innovation, so I was asking him if maybe the same kind of thing could be done here, and we both got, I think, pretty excited about that,” he added.

Gates also said they talked about fighting polio, which has been nearly eradicated globally but has seen cases in Pakistan, Afghanistan, Gaza, and Africa.

That appeared to spark Trump’s interest.

“He was fascinated to hear what he could do to maximize the chance that during the next four years that incredible milestone will be achieved,” Gates said. “I felt like he was energized and looking forward to helping to drive innovation. I was frankly impressed with how well he showed a lot of interest in the issues I brought up.”

Trump’s transition team didn’t immediately respond to a request for comment.

The meeting with Gates comes as he looks to fill out his cabinet. His pick to lead the Department of Health and Human Services is vaccine skeptic Robert F. Kennedy Jr. 

While Kennedy told lawmakers on Capitol Hill last month that he’s “all for the polio vaccine,” the New York Times reported earlier instances when he suggested the vaccine may have caused cancers “that killed many, many, many, many, many more people than polio ever did,” while rejecting the idea that the vaccine resulted in a sharp decline in polio.

For his part, Trump has said he’s a “big believer” in the polio vaccine and would protect it.

“You’re not going to lose the polio vaccine,” he told reporters last month. “That’s not going to happen.”