Dr. Anthony Fauci tested positive for COVID-19 for the second time in two weeks — an indicator of what’s known as COVID-19 rebound. Fauci says he treated his first bout of the virus with Paxlovid, a prescription oral antiviral drug. It worked, and Fauci tested negative. But then, it “reverted back to positive,” Fauci said. The CDC has warned about the potential for COVID-19 rebound symptoms after taking Paxlovid, though the drug is still recommended for people who are considered high risk.