Nonspecific effect of BCG vaccination at birth on early childhood infections: a randomized, clinical multicenter trial

Background: Childhood infections are common and Bacillus Calmette-Guérin (BCG) vaccination at birth may prevent these via nonspecific effects. Methods: A randomized, clinical multicenter trial. All women planning to give birth ( n = 16,521) at the three study sites were invited during the recruitment period. Participating children were randomized to receive BCG within 7 d of birth or to a no intervention control group. Parent-reported infections (events) were collected using telephone interviews at 3 and 13 mo. Data collectors were blinded to allocation. Results: The analyses included 4,224/4,262 (99%) and 4,192/4,262 (98%) children at 3 and 13 mo. From 0 to 3 mo, there were 291 events in the BCG group vs. 336 events in the control group, incidence rate ratio (IRR) = 0.87 (95% confidence interval (CI): 0.72 to 1.05). In this age group, the IRR was 0.62 (95% CI: 0.39 to 0.98) if the mother was BCG vaccinated. From 3 to 13 mo, there were 7,028 vs. 6,791 events, IRR = 1.02 (95% CI: 0.97 to 1.07). Conclusion: This study did not find a nonspecific public health benefit of BCG on parent-reported infections. BCG may have reduced the incidence of infections in children of BCG-vaccinated mothers during the first 3 mo.