US President Joe Biden tested positive for Covid-19 again on Saturday morning, per a letter from presidential physician Dr. Kevin O"Connor. Biden has experienced "no reemergence of symptoms, and continues to feel quite well" and will, as a result, not resume treatment, the White House said. O"Connor said the President tested negative on Tuesday evening, Wednesday morning, Thursday morning and Friday morning before testing positive on Saturday morning. "However, given his positive antigen test, he will reinitiate strict isolation procedures," the doctor noted. Biden ceased isolating on Wednesday after testing negative on successive antigen tests, celebrating his return in remarks from the White House Rose Garden. Biden"s physician said the President is not experiencing any symptoms but that he will isolate at the White House. — CNN