Chris Christie, who served as the 55th Governor of New Jersey from 2010 to 2018, is the latest of President Donald Trump‘s associates to have tested positive for COVID-19. Christie helped  Trump prepare for the first presidential debate earlier this week and announced his positive diagnosis on Twitter Saturday morning. “I just received word that I am positive for COVID-19. I want to thank all of my friends and colleagues who have reached out to ask how I was feeling in the last day or two. I will be receiving medical attention today and will keep the necessary folks apprised of my condition,” Christie writes

By Saturday afternoon, Christie had checked himself into a hospital as a “precautionary” measure.

Christie was among a group of senior Trump campaign staffers who were tested Friday after the president received a positive diagnosis. He was part of a team of advisers who helped prepare Trump for the first presidential debate on Tuesday. He told reporters that no one was wearing masks during the preparation sessions that occurred Sunday and Monday. Christie also attended Amy Coney Barrett‘s Supreme Court nomination ceremony last weekend, where most guests were not wearing masks or social distancing, and eight attendees have since tested positive. Christie has stated that he feels fine and is so far asymptomatic.