Does TB Vaccination Reduce COVID-19 Infection?: No Evidence from a Regression Discontinuity Analysis

Masao Fukui; Kohei Kawaguchi; Hiroaki Matsuura

There is no vaccine against the rapidly spreading novel Corona virus disease , which has contributed to more than 1.2 million infections and 70,000 deaths worldwide. In search of the effective prevention and treatment for COVID-19, some researchers found that there was a strong correlation between the heath effect of COVID-19 and national policy for Bacille Calmette-Guerin (BCG), a vaccine for tuberculosis (TB) disease. Miller et al. (2020) found that both morbidity and mortality due to COVID-19 are associated with early adoption or universal coverage of BCG vaccination, while Giovanni Sala and Tsuyoshi Miyakawa (2020) found that BCG vaccination slowed down the spread or progression of symptoms rather than reduced COVID-19 death. Shet et al. (2020) also examine the correlation with mortality. In the middle of global pandemic, the BCG hypothesis has quickly attracted the attention of popular media outlets such as Bloomberg (March-30-2020) and New York Times (April-5-2020) . Another study by Zhang et al. (2013) further indicates that the BCG strain with fewer epitopes deleted, such as the Japan and Russian/Bulgarian strain, are more likely to be effective due to higher and more frequent responses, although this paper is not about COVID-19. Clinical trial for these BCG strains are now initiated in several countries (For example, see Medical News Today (April-2-2020)).