After downplaying the seriousness of the virus for months, President Donald Trump and the First Lady Melania Trump tested positive for the coronavirus. He is now under quarantine.

Trump announced his diagnosis in a tweet early Friday morning, hours after media reports that his top aide, Hope Hicks, had tested positive for COVID-19 on Thursday but he proceeded with his schedule including a fundraiser in New Jersey.

Hours before his announcement about his diagnosis, he told guests at the Al Smith Dinner that “I just want to say that the end of the pandemic is in sight, and next year will be one of the greatest years in the history of our country.”

The positive test results have forced him to temporarily stop campaigning only 32 days before the Nov. 3 election. The president’s physician released a statement that Trump was well but would stay isolated in the White House.

Trump, 74, is among a group in the population that is at high risk for serious illness as a result of the coronavirus, which has now infected more than 7 million people across the country and has killed more than one million worldwide. Older men are more likely to die from COVID-19 than women. “If you don’t know anything about Donald Trump, just knowing that he’s a male, over 70, and appears to be overweight, right away, you can say he’s in the high-risk group,” Michael Baker, a professor with the department of global health at the University of Otago in Wellington who is an adviser to the New Zealand government, told the New York Times.

In a tweet on Friday, his Democratic challenger, former Vice President Joe Biden, said “Jill and I send our thoughts to President Trump and First Lady Melania Trump for a swift recovery. We will continue to pray for the health and safety of the president and his family.”

Biden and Trump were on the same stage Tuesday night during the first Presidential debate. Although the two men were socially distanced and did not shake hands, they did not wear masks and there was yelling and spitting during the 90-minute televised event. It is not known whether Biden has been tested for COVID-19 since the debate. Trump’s diagnosis also calls into question future debates scheduled in the upcoming weeks and confirmation hearings for Trump’s Supreme Court justice nominee Amy Coney Barrett.

Trump’s diagnosis comes as cases of COVID-19 are on the rise in the United States. Last Friday, the United States reported 55,759 cases, the largest single total in September, NBC News reported. Although Trump claims the US is on track to develop and distribute a vaccine before the end of the year, the World Health Organization said Sunday that a COVID-19 vaccine most likely won’t be available to the public until summer 2021.