There is no evidence that the Bacille Calmette-Guérin (BCG) #vaccine protects people against #infection with #SARSCoV2 #coronavirus causing #COVID19. But, 2 #clinicaltrials addressing this question are underway. WHO does not recommend BCG vaccine for the prevention of COVID-19. 
The review yielded 3 pre-prints (before peer-review), where authors compared incidence of #COVID19 cases in countries where the #BCGvaccine is used vs. countries where it is not used & observed countries that routinely used BCG in neonates had less #COVID19 cases to date.
Ecological studies are prone to significant bias from many confounders, for example differences in national demographics, differences in disease burden, difference in testing methods & rates for #COVID19 #coronavirus infections, the stage of the #pandemic in each country.
The review also yielded 2 registered protocols for #clinicaltrials, both of which aim to study the effects of #BCG #vaccination given to #healthcare workers directly involved in the care of patients with #COVID19. clinicaltrials.gov/ct2/show/NCT04…
clinicaltrials.gov/ct2/show/NCT04…
clinicaltrials.gov/ct2/show/NCT04…
#BCG #vaccine prevents severe forms of #tuberculosis in children & use of local supplies for #COVID19 may result in neonates not being vaccinated (=increase of TB disease / deaths). WHO continues to recommend neonatal BCG vaccination in countries with a high incidence of #TB.
For further info on #BCGcorona check out this excellent piece by @paimadhu - #BCG Against #Coronavirus: Less Hype & More Evidence, Please! #IDtwitter #medtwitter forbes.com/sites/madhukar… via @Forbes
