Percentage of adult patients admitted for COVID-19 by variant/subvariant predominance period and percentage of patients admitted for COVID-19 Omicron BA.5 vs influenza (RESP-NET, 2021–2022) for the following outcomes: A, ICU admission; B, invasive mechanical ventilation/ECMO; C, death. *A statistically significant change in trend was assessed with the Cochran-Armitage test. A statistically significant difference between COVID-19 Omicron BA.5 and influenza was assessed through logistic regression. ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; RESP-NET, Respiratory Virus Hospitalization Surveillance Network.