Researchers from the University of Colorado School of Medicine say the prescription drug Paxlovid remains a very effective treatment against the COVID-19 omicron variants.

A team of UC researchers conducted a study to evaluate the effectiveness of Paxlovid against the omicron variants BA.2, BA2.12.1, BA.4, and BA.5. 

The observational study used data from more than 28,000 patients in the UC Health System, one of the largest health systems in Colorado. They evaluated the rate of hospitalization or death and found that the use of nirmatrelvir–ritonavir, commonly known as Paxlovid, significantly reduced rates of hospitalization, death and hospitalizations of COVID-19 patients during the recent omicron surges. 

“This study was one of the first to strongly suggest a benefit for the antiviral medication, nirmatrelvir-ritonavir, also known as Paxlovid, to prevent hospitalization and death for patients infected with recent Omicron SARS-CoV-2 variants,” Neil Aggarwal, MD, MHSc, lead author of the study and an associate professor of medicine at the University of Colorado School of Medicine, said in a UC news release.

Aggarwal added that Paxlovid was effective in preventing hospitalization among almost all subgroups of outpatients that were assessed and who qualify for its use under the Emergency Use Authorization, including those who are vaccinated.

Recently, the Food and Drug Administration determined that physicians can prescribe Paxlovid even if the patient does not have a positive COVID-19 test.

“As a physician who can treat patients in the outpatient setting, I would be very comfortable using Paxlovid as a first-line treatment for adults acutely infected with COVID during the current Omicron phase, vaccinated or not, provided there are no contraindications to its use,” said Aggarwal, who is a critical care and pulmonary physician at UCHealth University of Colorado Hospital.

Adit Ginde, MD, MPH, professor of emergency medicine at the University of Colorado School of Medicine and a principal investigator on the project, said real-world evidence is particularly important for doctors who must make treatment recommendations for their patients.

“The laboratory data suggest that Paxlovid is still effective at neutralizing the virus in recent Omicron subvariants,” he said in the release. “However, we plan to evaluate ongoing clinical effectiveness in patients through our upcoming analyses.”

The article was published in the Feb. 10 issue of the edition of the Lancet Infectious Diseases.