The Effect of BCG vaccine on COVID-19 severity and mortality

Abstract

Aim: To investigate the effect of Bacille Calmette-Guérin (BCG) vaccine on the severity and mortality of the disease in hospitalized patients with COVID-19 in this study.
 Methods: This study was conducted as a retrospective observational study in a tertiary reference hospital in Turkey. The patients were divided into two groups as BCG positive and negative according to the presence of BCG scar. BCG positive and negative groups were compared in terms of radiological involvement, presence of hypoxia, need for intensive care unit (ICU) and intubation, and mortality.
 Results: BCG negative patients required more inpatient treatment (p = 0.001). The radiological involvement was more severe in BCG negative group (p = 0.016). Forty-one (22.7%) patients in the BCG positive group and twenty-two (42.3%) patients in the BCG negative group were treated in the ICU, and the difference was statistically significant (p = 0.007). More patients in the BCG negative group had hypoxia than the BCG positive group (59.6% vs. 40.9%, p = 0.018). The BCG negative group needed more intubation (21.2% and 8.8%, p = 0.024). Nine (17.3%) patients in the BCG negative group and 12 (6.6%) patients in the BCG positive group died, and the difference was statistically significant (p = 0.027).
 Conclusion: The length of hospital stay was longer, radiological involvement was more severe, the need for ICU and intubation, hypoxia and mortality were higher in BCG-unvaccinated patients with COVID-19.