Comparison of clinical characteristics and outcomes of critically ill adults with SARS-CoV-2 infection during Delta and Omicron variant predominance periods: a single-hospital retrospective cohort study.

In this single-hospital study, critically ill patients with SARS-CoV-2 infection experienced less severe respiratory disease during Omicron predominance, likely due to reduced variant-specific virulence. Vaccination likely reduced development of critical illness in adults with SARS-CoV-2 infection during Omicron predominance.