PREPRINT: BCG vaccination may be protective against Covid-19

Covid-19 virus has infected over 300,000 people and led to over 13,000 deaths in its first 3 months; yet the pattern of development is not uniform.. Mechanistic evidence exists to suggest that vaccination with Bacillus Calmette-Guérin (BCG), can have protective effects against viral infection. Herein we examine whether national programs which use BCG vaccination with the aim of reducing tuberculosis infections could account for the differential incidence and mortality observed in Covid-19 between various countries. Interpretation Countries with national program of whole population BCG vaccination appear to have a lower incidence and death rate from Covid-19. This may be due to the known immunological benefits of BCG vaccination. In the absence of a specific vaccination against Covid-19, population-based BCG vaccination may have a role in reducing the impact of this disease and is being studied in a prospective trial.

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