The World Health Organization on April 22 strongly recommended Pfizer's antiviral Paxlovid for COVID-19 patients at highest risk for hospitalization. The agency published its guidance in the BMJ.
"Pfizer's oral antiviral drug (a combination of nirmatrelvir and ritonavir tablets) is strongly recommended for patients with non-severe COVID-19 who are at highest risk of developing severe disease and hospitalization, such as unvaccinated, older or immunocompromised patients," the agency said in an accompanying news release.
The move is based on data from two trials involving 3,078 patients that found the treatment lowered the risk of hospitalization by 84 percent among high-risk patients. "In a high-risk group (over 10 percent risk of hospitalization), that means 84 fewer hospitalizations per 1,000 patients," the agency said.
Negligible benefits were found in lower risk patients, leading the agency to suggest against its use in this group. The WHO also updated its guidance on remdesivir. While the agency previously recommended against its use in all COVID-19 patients, it now suggests its use in those at high risk of hospitalization. Explicit recommendation for remdesivir's use is under review.
One more Paxlovid update:
Rebound symptoms: The Boston Globe on April 21 reported some patients have taken to social media to report their COVID-19 symptoms reappeared after taking the medication. Some also said they tested positive after completing the five-day treatment course, despite testing negative days earlier. The reports are anecdotal, having been self-reported by patients and physicians on social media platforms. Scientists are working to better understand what might be behind the symptom rebound and whether it means a person is still infectious.
"If you have a rebound after 12 days and are back at work and not wearing a mask, are you still contagious?" said Kathryn Stephenson, MD, assistant professor of medicine at Harvard Medical School in Boston and infectious disease physician at Boston-based Beth Israel Deaconess Medical Center. "If you are testing positive on a rapid antigen test, then you have a decent amount of virus and likely an infectious amount of the virus," she told the Globe.
Pfizer in a statement to the news outlet said it continues to monitor data for from clinical studies and real-world evidence, adding "We have not seen any resistance to Paxlovid and remain very confident in its clinical effectiveness."