US President Joe Biden’s COVID-19 symptoms continue to improve and now include “less troublesome” sore throat, runny nose, loose cough and body aches, his physician, Dr. Kevin O’Connor, said in a memo on Saturday, Reuters reported.

Biden’s lungs remain clear and his oxygen saturation “continues to be excellent on room air,” the doctor said.

Biden, 79, tested positive for COVID on Thursday, when the White House said he was experiencing mild symptoms. His diagnosis came as a highly contagious subvariant of the coronavirus drives a new wave of cases in the United States.

Biden most likely has that BA5 variant, O’Connor said.

“The BA5 variant is particularly transmissible and he will continue to isolate,” he said.

The White House has sought to underscore Biden’s ability to work through his illness. On Thursday it released a video of the president reassuring Americans he was doing fine, and on Friday he participated in virtual meetings with White House staff.