An experimental COVID-19 antiviral drug seems to be effective at preventing hospitalizations, but isn’t cleared by the U.S. Food and Drug Administration, according to a study published online Wednesday.
Study authors wrote that the trial was one of the first to test the drug in a largely vaccinated group, or 84 percent of participants. It had the same effect on people who were not vaccinated, they said.
A total of 933 people got a shot of interferon lambda in Canada and Brazil, and they were compared with 1,018 individuals who received a placebo. About 2.7 percent of those who got the interferon shot had to be hospitalized, compared with 5.6 percent who got the placebo, the paper found, noting it’s a difference of 51 percent.
“This phase 3 trial, which was conducted in a predominantly vaccinated population infected with various SARS-CoV-2 variants of concern, showed the efficacy of a single subcutaneous dose of pegylated interferon lambda administered within seven days after the onset of symptoms,” the study said, referring to the virus that causes COVID-19. “ This regimen resulted in a greater than 50 percent reduction in the risk of a primary-outcome event. Our trial findings were consistent across the SARS-CoV-2 variants of concern and across multiple subgroups according to vaccination status.”
In recent months, the Food and Drug Administration (FDA) has pulled authorization for several drugs that were used to treat COVID-19 across the United States, leaving patients with few options. Those decisions mean that Pfizer Inc.’s antiviral drug Paxlovid, Merck’s Lagevrio, convalescent plasma, and Gilead Sciences’ Veklury, known as remdesivir, are the primary treatments for the virus.

“Among persons with immunocompromise and their household members and close contacts, prevention measures, including wearing a high-quality and well-fitting mask, maintaining physical distance from others (at least six feet), improving indoor ventilation, practicing frequent handwashing, and developing a care plan, should be considered in addition to receipt of a bivalent booster dose,” said the CDC on Jan. 27.
The federal agency added that “it is important to wear a mask and maintain physical distance from others if it is not possible to avoid crowded indoor spaces … simple interventions should be used to improve ventilation in buildings and decrease SARS-CoV-2 transmission by improving air flow.”





