Enlarge / A field of Paxlovid, the Pfizer antiviral drug. (credit score: Getty | Europa Press Information)

Pfizer’s antiviral capsule Paxlovid is among the many most treasured instruments for hammering COVID-19; it may well knock again the relative danger of hospitalization and loss of life by 89 p.c in unvaccinated sufferers at excessive danger of extreme illness. However, as use of the handy drug has grown within the US, so have troubling reviews of rebound circumstances—individuals who took the capsule early of their an infection, started feeling higher, and even examined unfavourable however then slid again into signs and examined constructive once more days later.

It is nonetheless unclear simply how widespread the phenomenon is, nevertheless it actually occurs in some proportion of Paxlovid-treated sufferers. In Could, the Facilities for Illness Management and Prevention even issued a well being alert over the rebound reviews.

However, amid the rising consciousness, it has additionally change into clear that sufferers who haven’t been handled with Paxlovid may also rebound. In truth, in Pfizer’s scientific trials of Paxlovid, researchers famous that about 1 p.c to 2 p.c of each remedy and placebo teams had rebounds.