Growing numbers of people who've gotten COVID-19 and started taking the Pfizer antiviral medication Paxlovid have found that their infections went away, only to come back again a few days later. The "rebound" cases have reportedly not been serious, but have been sources of questions. Does this mean isolation should start over? Am I contagious again?
The "rebound COVID-19" effect has been described anecdotally by people who've taken Paxlovid in recent months. As those numbers grew, it became clear that this was not a random coincidence. And after monitoring the issue, last week CDC address the matter formally.
The agency reported that around 2 percent of people who take the antiviral experience the COVID rebound effect. During that time, they seem to have the potential to transmit the virus again, if briefly, and should act accordingly.
But while this is worth being aware of, it doesn't change the overall picture. Paxlovid has proven to be highly effective at preventing escalation of COVID-19 from mild to severe. Those who start taking the medication within a few (technically 5) days of infection have dramatically lower risk of ending up in the hospital.
And that remains the bottom line. It can be confusing to those who think they're in the clear, only to test positive again the next day. But this is not a reason to avoid the medication or take it to mean the drug doesn't work. Have a plan to get this drug as soon as you test positive. The rebound effect doesn't change that.
At the moment, this is a footnote, not a counter-argument. It's something to be aware of, but not to worry over. Most likely, these observations will cause experts to rethink exactly how to best prescribe the drug to minimize rebound.
The more salient concern is looming lack of access to the drug as we head into fall and winter surges with tenuous commitments to funding. It was bad enough to spend the last two holiday seasons in the throes of viral spread in every airport. It would be another level to watch infected people unable to be treated with an effective medication because they just can't get it.