Wasington, 27 July (CNN)- President Joe Biden has tested negative for Covid after a five-day isolation and will discontinue his isolation on Wednesday, his physician says.

Biden took two antigen tests, one on Tuesday evening and one on Wednesday morning -- that were both negative, Dr. Kevin O'Connor wrote in his letter.

The President will wear a well-fitting mask for 10 days to prevent the spread of the virus, and he will increase the frequency with which he is tested to detect for any possible resurgence of the virus.

O'Connor cited the potential for "rebound" after Biden received the antiviral Paxlovid in explaining the more frequent testing.