The fourth wave: vaccination status and intensive care unit mortality at a large hospital system in New York City.

Background: We aim to describe the demographics and outcomes of patients with severe disease with the Omicron variant. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus continues to mutate, and the availability of vaccines and boosters continue to rise, it is important to understand the health care burden of new variants. We analyze patients admitted to intensive care units (ICUs) in a large Academic Health System during New York City's fourth surge beginning on November 27, 2021.

Methods: All patients admitted to an ICU were included in the primary analysis. Key demographics and outcomes were retrospectively compared between patients stratified by vaccination status. Univariate and multivariate logistic regression was used to identify risk factors for in-hospital mortality.

Results: In-hospital mortality for all admitted patients during the fourth wave was significantly lower than in previous waves. However, among patients requiring intensive care, in-hospital mortality was high across all levels of vaccination status. In a multivariate model older age was associated with increased in-hospital mortality, vaccination status of overdue for booster was associated with decreased in hospital mortality, and vaccination status of up-to-date with vaccination showed a trend to reduced mortality.

Conclusions: In-hospital mortality of patients with severe respiratory failure from coronavirus disease 2019 (COVID-19) remains high despite decreasing overall mortality. Vaccination against SARS-CoV-2 was protective against mortality. Vaccination remains the best and safest way to protect against serious illness and death from COVID-19. It remains unclear that any other treatment will have success in changing the natural history of the disease.