{"id":10426,"date":"2022-05-04T09:59:04","date_gmt":"2022-05-04T13:59:04","guid":{"rendered":"https:\/\/blogs.nejm.org\/hiv-id-observations\/?p=10426"},"modified":"2022-05-23T15:04:33","modified_gmt":"2022-05-23T19:04:33","slug":"more-on-relapses-after-paxlovid-treatment-for-covid-19","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/more-on-relapses-after-paxlovid-treatment-for-covid-19\/2022\/05\/04\/","title":{"rendered":"More on Relapses after Paxlovid Treatment for COVID-19"},"content":{"rendered":"

Unless you’ve been hiding under a rock, you’ve heard that some people treated for COVID-19 with nirmatrelvir\/ritonavir (Paxlovid) experience a relapse in illness shortly after stopping treatment.<\/a><\/p>\n

It’s both a recurrence of symptoms and a positive antigen test — sometimes after the test became negative. One\u00a0case report<\/a>\u00a0published as a pre-print shows that a relapse can have a very low cycle threshold, meaning a high viral load:<\/p>\n

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Relapses vary in severity, from very mild and brief to worse than the initial illness. Check out the comments in my previous post for a sampling.<\/p>\n

Some posit that the immune system doesn’t get a chance to mount a full response<\/a> since the drug quickly reduces exposure to viral antigens. Others note that certain individuals experience prolonged viral replication, symptoms, and antigen test positivity, and perhaps it’s this group that’s destined to rebound after the 5 days of Paxlovid use. The drug knocks down replication for a while, but not long enough, so it rebounds.<\/p>\n

Maybe it’s both — these aren’t mutually exclusive hypotheses. Regardless, as noted in my prior post, there’s still plenty we don’t know. But given the rapidly increasing use of Paxlovid nationally<\/a>, I thought it worth this brief update about two important things we’ve learned since then, plus my opinion on a commonly asked question about contagiousness.<\/p>\n

First, Pfizer offered additional details from their EPIC-HR study, citing that late viral rebounds occurred in roughly the same proportion of treated and untreated participants in their trial — around 2%:<\/p>\n

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UPDATE: Pfizer gave me the figures regarding the proportion of people who had Covid rebound in the Paxlovid clinical trial: About 2% of participants who got the drug experienced rebound, compared with ~1.5% of those who received the placebo rebounding within the same time frame.<\/p>\n

— Benjamin Ryan (@benryanwriter) April 28, 2022<\/a><\/p><\/blockquote>\n