The effectiveness of novel oral antiviral treatment for non-hospitalized high-risk patients with COVID-19 during predominance of omicron XBB subvariants.

Objectives: This study investigated the association between nirmatrelvir plus ritonavir (NMV-r) or molnupiravir and the outcomes of non-hospitalized high-risk patients with COVID-19 during Omicron XBB subvariants.

Methods: The retrospective cohort study used the TriNetX US collaborative network to identify non-hospitalized high-risk adult patients with COVID-19 between 1 February 2023, and 31 August 2023. Propensity score matching (PSM) was used to match patients receiving NMV-r or MOV (the study group) with those not receiving antivirals (the control group).

Results: Using PSM, two cohorts of 17,654 patients each with balanced baseline characteristics were identified. During the follow-up period, the study group had a lower risk of all-cause hospitalization, or death (3.2% [ = 564] versus 3.8% [ = 669]; HR, 0.796; 95% confidence interval [CI], 95% CI, 0.712-0.891). Compared with the control group, the study group had a significantly lower risk of all-cause hospitalization (3.1% vs. 3.4%; HR, 0.847; 95% CI, 0.754-0.950) and mortality (0.1% vs. 0.4%; HR, 0.295; 95% CI, 0.183-0.476).

Conclusion: The use of novel oral antiviral including NMV-r or MOV can be associated with a lower risk of all-cause hospitalization, or death in non-hospitalized high-risk patients with COVID-19 during Omicron XBB wave.