Biden, 79, came down with the virus a second time three days after he had emerged from isolation from his initial bout with COVID-19, reported on Jul 21.
There have been rare rebound cases documented among a small minority of those, who like Biden, were prescribed the anti-viral medication Paxlovid, which has been proved to reduce the risk of serious illness and death from the virus among those at highest risk.
During his first go-around with the virus, Biden’s primary symptoms were a runny nose, fatigue and a loose cough, his doctor said at the time. During his rebound case, O’Connor said only Biden’s cough returned and had “almost completely resolved” by Friday.
Regulators are still studying the prevalence and virulence of rebound cases, but the Centers for Disease Control and Prevention in May warned doctors that it has been reported to occur within two days to eight days after initially testing negative for the virus.
“Limited information currently available from case reports suggests that persons treated with Paxlovid who experience COVID-19 rebound have had mild illness; there are no reports of severe disease,” the agency said at the time.