Older patients treated with nirmatrelvir boosted by ritonavir (Paxlovid) for COVID-19 had lower rates of hospitalization and death compared with those not treated with the antiviral during the Omicron wave, according to an observational retrospective cohort study from Israel.

Among patients ages 65 and older, the rate of hospitalization due to COVID was 14.7 cases per 100,000 person-days for the 2,484 patients who received nirmatrelvir compared with 58.9 cases per 100,000 person-days for the 40,337 untreated patients (adjusted HR 0.27, 95% CI 0.15-0.49), reported Ronen Arbel, PhD, of Clalit Health Services in Tel Aviv, and colleagues.

Death occurred in two nirmatrelvir-treated patients and in 158 untreated patients (aHR 0.21, 95% CI 0.05-0.82), they said in the New England Journal of Medicine.

For patients ages 40 to 64, the rate of hospitalization was 15.2 cases per 100,000 person-days among treated patients and 15.8 cases per 100,000 person-days among untreated patients (aHR 0.74, 95% CI 0.35-1.58). Deaths were similar for this age group as well (aHR 1.32, 95% CI 0.16-10.75).

“Our results conform to CDC guidelines to treat high-risk patients, prioritizing those above 65,” Arbel told MedPage Today in an email. “No evidence of benefit was found in younger adults.”