President Trump’s bout with COVID-19 is casting uncertainty over the second presidential debate, even as both campaigns signal a willingness to participate in next week’s event.

The president intends to participate in person at the debate in Miami, his campaign said Tuesday. Democratic nominee Joe Biden told reporters a day earlier that he would defer to medical experts on whether it would be safe to hold the event but appeared willing to take part if they signed off.

As the debate commission mulls how to move forward given all the unknowns, health experts suggested it’s not worth the risk for the two candidates, both in their 70s, to debate in person when there are alternatives available.

“With technology the way it is right now, why bother? You don’t actually need to do a debate with two people standing together physically in a room,” said Jill Roberts, an epidemiologist at the University of South Florida.

“And in that case, we wouldn’t have to worry about whether one person was positive or who was at risk,” she said.

The town hall forum for the debate, slated for the Arsht Center for the Performing Arts in Miami, means voters will be in the auditorium with the candidates and moderator. The setting creates an added layer of risk, as the Centers for Disease Control and Prevention (CDC) issued guidance Monday stating the coronavirus can spread through “airborne transmission” to people who are more than 6 feet away in indoor, poorly ventilated spaces.

Both candidates this week signaled a readiness to attend and participate in person, even though both are more than 70 years old, putting them at higher risk for having serious complications from COVID-19.

“I am looking forward to the debate on the evening of Thursday, October 15th in Miami. It will be great!” the president tweeted Tuesday.

Biden has been on the campaign trail in recent days and has tested negative for the virus multiple times after sharing the stage with Trump in Cleveland for the first debate on Sept. 29. On Monday, the day Trump was discharged from Walter Reed National Military Medical Center, Biden said he would defer to health experts on the second debate.

“I’m not an expert on it, but I think we should be very cautious, as I’ve thought all along,” he told reporters. “And I’m going to continue to listen to the scientists. But I’m looking forward to having a town hall meeting if that occurs.”

The biggest wild card is Trump’s health, both in terms of whether he will be well enough to debate in person and whether he will be far enough along in his recovery to avoid endangering others in the building.

Trump said he first tested positive on Thursday after returning from a fundraiser in New Jersey and has been symptomatic since at least Friday. White House officials and the president’s physician have refused to disclose when the president last tested negative, making it difficult to determine when it might be safe for him to venture out again.

The president was on oxygen as recently as Saturday and suffered from fatigue and a fever early in his diagnosis. He was discharged from the hospital after doctors said his vitals had improved and he passed clinical evaluations. But they acknowledged he is not out of the woods yet, citing next Monday as the point at which they will breathe a sigh of relief.

CDC guidelines state that adults with mild to moderate COVID-19 can be around others 10 days after the onset of symptoms so long as they have gone 24 hours without a fever and other symptoms are improving.

The debate is scheduled to take place 14 days from Trump’s positive test on Thursday.

David Dowdy, an associate professor at the Johns Hopkins Bloomberg School of Public Health, argued that there’s no reason to hold the event in person and create the risk of exposure, “even though the risk of that exposure might be low.”

“The much greater risk is that in organizing this entire event, someone, particularly someone from the White House that has had a number of infections recently, could easily be infected and not know it,” Dowdy added.

The Commission on Presidential Debates has made no announcements on potential alterations to the Oct. 15 event, though organizers are said to be considering holding it outdoors or with added safety measures in place.

For Wednesday’s vice presidential debate, the commission is installing a plexiglass barrier between the candidates, and their podiums will be more than 12 feet apart. There will be no physical greeting between the two candidates, just as Trump and Biden did not shake hands before the first debate.

Experts argue that Trump’s positive test makes the Miami debate an entirely different situation. They pointed to the conduct of his team during last week’s event in Cleveland, where Trump arrived too late to get a COVID-19 test on site and members of his entourage flouted the rules by removing their masks upon arrival in the debate hall.

“I think what concerns me is the signaling effect,” said Jeremy Konyndyk, a senior fellow at the Center for Global Development who headed the U.S. Agency for International Development’s Office of Foreign Disaster Assistance in the Obama administration.

“They’re just signaling that the guidance around preventing transmission can be ignored at anyone’s discretion,” he said of the behavior and rhetoric from Trump and his campaign. “They’re signaling that we’re not taking the public health guidance seriously, so you don’t have to either. That is very, very damaging.”