That finding comes after researchers at the Veterans Administration Medical Center (VAMC) in Boston and Columbia University looked into pandemic cases that return after treatment with the antiviral drug, which has seen an increase in usage over the past two months in the United States.
Dr. Michael Charness of the VAMC said he and his colleagues found two instances of people who’ve transmitted to others when their infection came back.
In one case, a 67-year-old man infected his 6-month-old grandson, though he didn’t feel symptoms when he saw the baby. In another, a 63-year-old man infected two family members during three days of relapse after Paxlovid.
“People who experience rebound are at risk of transmitting to other people, even though they’re outside what people accept as the usual window for being able to transmit,” said Charness, noting it's not entirely clear that rebound COVID is linked to Paxlovid.
According to the CDC, people who’ve tested positive again and whose symptoms come back after finishing their antiviral pills should be isolated for five full days. After that, people can end their isolation period as long as their fever has gone for 24 hours without fever-reducing medication. The CDC also recommends that people wear masks for 10 days after their symptoms come back.