President Joe Biden has tested positive again for COVID-19 as doctors say the result is due to a "rebound" case with the virus. RELATED: https://bit.ly/3Bt9AEY President Joe Biden has no reemergence of symptoms, Kevin O'Connor, physician to the president, said in a letter, and as a result, his doctors will not restart medical treatment. Still, Biden said he's returned to isolation. » Subscribe to USA TODAY: http://bit.ly/1xa3XAh » Watch more on this and other topics from USA TODAY: https://bit.ly/3JmYKlN » USA TODAY delivers current local and national news, sports, entertainment, finance, technology, and more through award-winning journalism, photos, videos and VR.