Significantly Improved COVID-19 Outcomes in Countries with Higher BCG Vaccination Coverage: A Multivariable Analysis

COVID-19 has spread to 210 countries within 3 months. We tested the hypothesis that the vaccination with BCG correlates with a better outcome for COVID-19 patients. Our analysis covers 55 countries, complying with predetermined thresholds on population size and deaths per million (DPM). We found a strong negative correlation between the years of BCG administration and a lower DPM along with the pandemic progression in time. The results from multivariable regression tests with 22 economical, demographic, and health-related quantitative properties for each country substantiate the dominant contribution of BCG administration years to the COVID-19 outcomes. Analyzing countries according to an age-group partition reveals that the strongest correlation is attributed to the coverage in BCG vaccination of the young population and mostly to recent years immunization. We propose that BCG immunization coverage, especially among the most recently vaccinated contributes to attenuation of the spread and severity of the COVID-19 pandemic.