Related Articles BCG vaccine Worrying proposal for COVID 19 Vaccine 2020 Dec 13 Authors Sarinho E Goudouris E Sol D Abstract Bacille Calmette Gu rin BCG vaccine is proven to be effective in protecting against severe tuberculosis It has been suggested to be able to exert a non specific beneficial effect as protection against other infectious diseases The duration of protection against tuberculosis is estimated to be from 10 to 15 years but the duration of the protection against other infections is not known maybe up to 20 years maybe much shorter than that We don t know it for sure BCG induced trained immunity paradigm is based on experimental models cohort studies with low number of individuals and some epidemiological data in which other possible interfering factors are not controlled The titles and scopes of scientific articles should be cautiously considered as they can promote indications of getting vaccinated or revaccinated with BCG before its effectiveness is confirmed and recommendations are published Besides revaccination with BCG can put at serious risk patients with primary or secondary immunodeficiency Maybe BCG vaccine is effective in preventing COVID 19 deaths or reducing its severity but may the effect of this vaccine be relevant even with poor health politics and assistance It is very difficult to compare the epidemiologic data about COVID 19 in different countries There are countless factors mainly social and related to the healthcare system which can be more decisive than the hypothesis of trained immunity induced by BCG Until now we can say that BCG s protective role is at least insufficient given many other factors that corroborate SARS CoV 2 infection and or its severity PMID 33341305 PubMed as supplied by publisher