Clinical outcome of hospitalized COVID-19 patients in relation to COVID-vaccination status

Abstract

Background: Corona virus disease 2019 (COVID-19) pandemic had placed an enormous burden on health systems worldwide, with severe disease and mortality disproportionately affecting unvaccinated individuals and those with underlying comorbidities. Vaccination remains the most effective strategy to prevent severe outcomes, yet evidence from South Asian settings remains limited. This study examined the clinical outcomes of hospitalized COVID-19 patients in Bangladesh in relation to their COVID-vaccination status. Methods: This hospital-based retrospective cross-sectional study was conducted at the dedicated COVID-19 ward under the Department of Internal Medicine in Bangladesh Medical University, Dhaka, Bangladesh during August 2021 to September 2021. A total of 492 adult patients were included consecutively irrespective of age and sex, diagnosed with COVID-19 based on clinical history, radiological findings and reverse-transcriptase polymerase chain reaction (RT-PCR) testing, who were treated under National Guidelines on Clinical Management of Coronavirus Disease 2019, were retrospectively enrolled in this study. The collected data were methodologically organized for computer entry and analysis. The data were analyzed using Statistical Package for Social Sciences (SPSS) version 29.0 (SPSS Inc., Chicago, IL, USA). Vaccination status was classified as unvaccinated (not a single dose received), partially vaccinated (received first dose only) and vaccinated (received at least two doses) of COVID-19 vaccine. Results: Total patients were 492, with mean age of 51.8 ± 17.4 years; 40.9% were aged e‑60 years and 66.9% had at least one comorbidity, most commonly diabetes mellitus (43.3%) and hypertension (37.6%). Among the study participants, only 16.9% were fully vaccinated followed by 5.5% partially vaccinated and 60.7% remained unvaccinated. Severe illness occurred in 75.6% of patients, disproportionately affecting the unvaccinated (83.1% vs 16.9% in vaccinated; p<0.001). Overall mortality was 17.1%, with vaccinated patients experiencing significantly lower mortality (6.0% vs. 94.0%; p<0.001). Vaccination reduced the odds of severe illness by 68% (OR 0.317, 95% CI: 0.201–0.500) and mortality by 82% (OR 0.183, 95% CI: 0.072–0.463). Intensive care unit (ICU) transfer was also less frequent among vaccinated patients (OR 0.342, 95% CI: 0.119–0.979). Length of hospital stay was slightly shorter among vaccinated patients (11.6 vs. 12.8 days), though it was not statistically significant. Conclusion: Vaccination was protective against severe COVID-19 outcomes, including ICU transfer and death.  

BIRDEM Med J 2026; 16(1): 3-8