Association of vaccination status and severity of SARS-CoV-2 infections in hospitalized patients.

Vaccination is considered the most promising approach for addressing the COVID-19 pandemic. However, even vaccinated people remain at risk. In this study, we examined the association between levels of vaccination and clinical outcomes in hospitalized patients. We conducted a retrospective review of adults hospitalized with COVID-19 infection. Of 484 patients, fully vaccinated (OR = 0.49, p = 0.001) and updated patients (OR = 0.46, p = 0.004) had significantly lower probability of critical severity compared to unvaccinated. Vaccination status is significantly related with 30-day mortality (p = 0.005) but not significantly associated with need for respiratory support or ICU stay. Mean length of stay (LOS) of 6.6 days among boosted patients is significantly lower than patients with no vaccination status (10.7 d, p < 0.001). Our study findings provide real-world evidence of the benefit of booster vaccinations against critical infection and death as well as shortcomings in ICU stay, length of stay or need for ventilatory support.