Association of BCG vaccination policy with prevalence and mortality of COVID-19

Giovanni Sala; Tsuyoshi Miyakawa

Also, the role of the observed between-country differences concerning the date of the spread of the COVID-19 is still unclear. In brief, the current state of affairs might change quickly and, therefore, our findings should be interpreted with caution. That being said, we have found a highly significant difference among the BCG groups of the slope of increase of the cases in log scale, that is, adjusted by the . CC-BY 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Potential mechanisms BCG, originally developed against tuberculosis, is hypothesized to develop 'frontline' immunity, training it to respond non-specifically to certain viruses with greater intensity 7, 3, 4 . This idea is supported by clinical and epidemiological studies, which showed that BCG appeared to lower overall mortality in children 5,2,6 . BCG, which can remain alive in the human skin for several months, triggers not only specific memory B and T cells, but also stimulates the innate blood cells for a prolonged period 7 . In a randomized placebo-controlled study, it was shown that author/funder, who has granted medRxiv a license to display the preprint in perpetuity.