How Did Mortality Rates from Covid-19 Differ between Vaccinated and Unvaccinated People in a Tertiary Level Hospital of Bangladesh?

This study aims to find out the difference in mortality rates between vaccinated & non-vaccinated Covid-19 positive patients who were admitted in a tertiary centre (Ward and Intensive care unit) of Bangladesh. Retrospective analysis of data over 6 weeks in February 2022- March 2022, 100 confirmed Covid-19 positive patients were included- 50 patients from ICU and 50 patients from ward irrespective of age, gender, vaccination status and co-morbidities. Seventy five percent (75.0%) of all confirmed Covid-19 positive patients were vaccinated. Mortality among vaccinated people was less compared to non-vaccinated population 41.3% vs. 52%. Interestingly it was found pregnancy was the most significant risk factor in childbearing age female group- 86.7% of patients (pregnant and peripartum) required Intensive care admission and mortality was 40.0% although none of them had any recorded co-morbidities. Again, mortality among vaccinated was significantly less (35.7%) compared to 100.0% mortality among unvaccinated. Mortality rate among patient admitted in intensive care was significantly high compared to patients treated in ward- 72.0% vs. 16.0%. In ICU 83.0% of patients who died were vaccinated (90.0% had 2 doses and 10.0% had 3 doses). On the other hand, 87.5% who died in ward were unvaccinated. Among the survivors from intensive care units- 93.0% were vaccinated compared to 7.0% unvaccinated. Pre-existing co-morbidities increased mortality (59.0%) compared to 40.9% mortality in patients without any previous medical conditions. We found vaccination against Covid-19 reduces the rate of death irrespective of co-morbidities or severity of disease. Recovery rate was significantly increased in vaccinated patients requiring intensive care support. Pregnancy was found to be the most important risk factor for Intensive care admission and mortality in otherwise healthy childbearing age females and mortality was significantly high (100.0% though limited data availability) in unvaccinated. These results require further revalidation on larger population.