Safety of inadvertent anthrax vaccination during pregnancy: An analysis of birth defects in the U.S. military population, 2003-2010

No strong associations between inadvertent AVA vaccination during pregnancy and birth defects risk were observed. Marginal associations between prepregnancy vaccination or never vaccinated women and birth defects risk was observed when compared to postpregnancy vaccination. These findings may be due to self-selection and/or reverse causation bias when assessing comparisons with postpregnancy vaccination, and a “healthy worker” effect when assessing comparisons with women never vaccinated.