Impact of pediatric Bacillus Calmette Gurin vaccination on clinical outcomes of COVID-19 in adult hospitalized patients

Background and Aim The role of BCG vaccination in childhood on the outcomes of Covid-19 infection is still unclear. This study aimed to examine the association between BCG vaccination status and the severity, ICU admission, and mortality of Covid-19 pneumonia patients. Materials and Methods This was a cross-sectional study of Covid-19 pneumonia patients admitted to Bo Ali Sinai Medical Education Center in Qazvin, Iran, from April 2022 to January 2023. Data on demographic characteristics, comorbidities, BCG vaccination status, and in-hospital outcomes, including severity of illness, ICU admission, and mortality, were collected and analyzed. Results Of 203 patients (mean age 56 years, 43.8% male), 52.7% had a history of BCG vaccination. Logistic regression analysis showed that the number of comorbidities, lymphocyte percentage, and oxygen saturation at admission were inversely associated with ICU admission (odds ratio [OR] = 1.6, 0.9, and 0.8, respectively). Age and respiratory rate were positively associated with mortality (OR=1.2, 1.5). BCG vaccination and respiratory rate were positively associated with severity of Covid-19 (OR=8.5, 4.8), while oxygen saturation was negatively associated with severity of Covid-19 (OR=0.009). BCG vaccination status did not have a significant effect on ICU admission and mortality. Conclusions This study did not find evidence that BCG vaccination in childhood alters the prognosis of Covid-19 pneumonia. Age and respiratory rate were the main predictors of in-hospital mortality in Covid-19 pneumonia patients.