Khodr ZG, et al. - This retrospective cohort study investigated the link between timing of maternal tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) vaccination during pregnancy and acute respiratory infection (ARI) in infants <2 months of age. Findings indicated that irrespective of Tdap vaccination prior to pregnancy, maternal Tdap vaccination between 27 and 36 weeks of pregnancy versus no vaccination during pregnancy conferred protection against infant ARI in the first 2 months of life. Essentially, results strongly supported current Advisory Committee on Immunization Practices (ACIP) guidelines recommending Tdap vaccination in late pregnancy for every pregnancy.