Introduction: This study elucidates factors affecting the severity and mortality in pre-Omicron and Omicron strains of SARS-CoV-2 and vaccination impact.
Methods: This single-center retrospective observational study included 1598 hospitalized COVID-19 patients. Patients were grouped into "pre-Omicron" and "Omicron" periods. The endpoint was severe COVID-19 (oxygen saturation [SpO2 ] < 94%). Logistic regression examined associations between clinical factors, including hemodialysis (HD), and the endpoint.
Results: The HD patient mortality rate dropped from 16% pre-Omicron to 4% during the Omicron epidemic. HD was significantly associated with the study endpoint in both epidemics. Unvaccinated patients had a greater risk of reaching the study endpoint among patients receiving HD.
Conclusion: These findings suggest that the Omicron variant, alongside vaccination and healthcare innovations, led to improved prognoses for HD patients with COVID-19. However, HD patients remain at a greater risk for severe COVID-19. Increased vaccination rates and optimized healthcare resources can improve this vulnerable population's prognoses.
Keywords: COVID-19; Omicron variant; SARS-CoV-2; hemodialysis; vaccination.
© 2023 International Society for Apheresis and Japanese Society for Apheresis.