Some coronavirus-positive patients who have completed treatment of the anti-COVID drug Paxlovid are rebounding into illness, and experts are urging people to be cautious if they develop COVID-like symptoms again and become infectious. It’s unclear how often “post-Paxlovid rebound” occurs, but UC San Francisco Department of Medicine chair Dr. Robert Wachter said he knows of at least one person who completed Paxlovid treatment and then became infectious again, spreading the virus to other family members. “It can happen,” Wachter tweeted.