When Anthony Fauci announced in June that he had experienced a “rebound” case of COVID-19—testing positive mere days after a negative test result—many Americans were shocked this could happen. But in the intervening weeks, a growing number of people have suffered a rebound themselves or encountered others in similar straights, including another high-profile case just last week of President Joe Biden.
“It’s hard to ignore the anecdotal evidence of rebounding peppered throughout social and mass media,” says Katelyn Jetelina, an epidemiologist at the University of Texas School of Public Health who writes the popular blog Your Local Epidemiologist.
A rebound occurs when a person tests positive for COVID-19 or suffers a recurrence of symptoms between two and eight days after recovering from the initial infection and testing negative, according to a health alert for physicians issued by the Centers for Disease Control and Prevention in May. In many cases, the rebound is happening in people taking an antiviral medication, which is recommended for individuals at high risk of progressing to a severe form of COVID-19, ending up in the hospital or dying from the infection.