Mortality Reduction in Vaccinated COVID-19 Patients

The sample size for this study was determined based on the observation of mortality differences between various groups, akin to effective pharmacological interventions. The calculation was derived from previously reported mortality rates following the use or non-use of corticosteroids (41.3% and 24.8%, respectively) in hospitalized COVID-19 patients requiring high-flow oxygen [18 (link)]. To achieve the required power of 0.8, 126 patients were needed in each group (vaccinated and unvaccinated). Following the study’s completion, a post hoc statistical power analysis was conducted, revealing that being vaccinated (with two doses of BNT162b2 (Pfizer—BioNTech) or ChAdOx1-S (AstraZeneca) vaccines) reduces mortality in hospitalized COVID-19 patients, resulting in a statistical power of 93.3% for the vaccinated group and 96% for the subgroup vaccinated with BNT162b2.