Late last year it looked like a key to “living with Covid” had finally been found. Pfizer’s antiviral drug Paxlovid had been approved, giving the newly infected the option of popping a pill to tackle their symptoms, cutting hospitalisations and other damaging effects of the disease.
But new studies have raised significant questions about a drug that was even mentioned by US president Joe Biden in his annual State of the Union address.
These include how well it works in lower-risk patients, why some suffer Covid-19 “rebound” — symptoms returning after they stop taking the drug — and whether the virus could become resistant to it.
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