WASHINGTON, D.C. (WNCN) — President Joe Biden has tested positive for COVID-19 Saturday morning, after originally testing positive July 21.

In the White House Physician’s letter, Biden tested negative for COVID-19 Tuesday evening, Wednesday morning, Thursday morning and Friday morning. He then tested positive for COVID-19 Saturday morning.

Dr. Kevin O’Connor, physician to the president, said Biden’s positive test represents “rebound positivity.”

The President increased his testing after O’Connor acknowledged the potential for “rebound” COVID positivity observed in a small percentage of patients treated with PAXLOVID.

The President has no symptoms and is feeling well. The letter stated that there is no reason to reinstate treatment.

According to the letter, Biden will reinitiate strict isolation procedures.