The effectiveness of Paxlovid treatment in long-term care facilities in South Korea during the outbreak of the Omicron variant of SARS-CoV-2

Objectives: On November 5, 2021, Pfizer Inc. announced Paxlovid (nirmatrelvir + ritonavir) as a treatment method that could reduce the risk of hospitalization or death for patients with confirmed coronavirus disease 2019 (COVID-19). Methods: From February 6, 2022 to April 2, 2022, the incidence of COVID-19 and the effects of treatment with Paxlovid were analyzed in 2,241 patients and workers at 5 long-term care facilities during the outbreak of the Omicron variant of severe acute respiratory syndrome coronavirus 2 in South Korea. Results: The rate of severe illness or death in the group given Paxlovid was 51% lower than that of the non-Paxlovid group (adjusted risk ratio [aRR], 0.49; 95% confidence interval [CI], 0.24−0.98). Compared to unvaccinated patients, patients who had completed 3 doses of the vaccine had a 71% reduced rate of severe illness or death (aRR, 0.29; 95% CI, 0.13−0.64) and a 65% reduced death rate (aRR, 0.35; 95% CI, 0.15−0.79). Conclusion: Patients given Paxlovid showed a lower rate of severe illness or death and a lower fatality rate than those who did not receive Paxlovid. Patients who received 3 doses of the vaccine had a lower rate of severe illness or death and a lower fatality rate than the unvaccinated group.