Does BCG revaccination protect against the development of asthma

Summary Single BCG vaccination has been considered as a protective factor against asthma. However the effect of a second dose of BCG on the prevalence rate of asthma and asthma–allergic rhinitis–eczema comorbidity has not been studied exclusively among adolescents. In this ISAAC protocol-based cross sectional study we assessed the association between one single versus two doses of BCG among 2213 individuals aged 13–14 years old. We found no association between BCG revaccination and asthma, associated (OR = 0.68, 95% CI, 0.37–1.25) or not to allergic rhinitis and/or atopic eczema (OR = 1.07, 95% CI, 0.84–1.36).