WASHINGTON (AP) — President Joe Biden has tested positive for COVID-19 again, slightly more than three days after he was cleared to exit coronavirus isolation. Medical authorities say such “rebound” infections following treatment with an anti-viral drug are rare. White House physician Dr. Kevin O’Connor reports that Biden isn’t showing symptoms and feels well. The Centers for Disease Control and Prevention says most rebound cases remain mild and that severe disease during that period hasn’t been reported. The White House says Biden will follow CDC guidelines and isolate for at least five days.