A week after his Covid relapse, US President Joe Biden tested negative for the corona virus on Saturday.

As a precaution, however, Biden will remain in isolation until a second negative test result, President Doctor Kevin O'Connor wrote in a letter published by the White House on Saturday.

The 79-year-old feels very good.

The US President had tested positive around two and a half weeks ago and was treated with the Covid drug Paxlovid.

After six days, he ended his corona isolation as a result of a negative test.

Then, on Saturday last week, a test was positive again for the first time, and several such results followed.

O'Connor had spoken of a "relapse" observed in rare cases in patients treated with Paxlovid.

Biden is fully vaccinated against the coronavirus and boosted twice.

He is the oldest president the United States has ever had.

A medical examination last November found him “fit” to hold office.