In 2012, prompted by evidence of reemergence of pertussis disease and associated infant mortality, maternal immunization with Tdap was recommended in the US and the UK as the most immediate and direct intervention to decrease pertussis in the first few months of life (22). Several other countries with high burden of pertussis disease in the Americas, Europe, and Australia also adopted this recommendation. Importantly, research on maternal immunization with Tdap flourished, filling critical gaps of information, such as understanding the optimal timing for maternal vaccination in the second trimester of gestation to achieve higher antibody concentrations in infants at birth, and better and longer duration of protection in the first few months of life until active immunization with pertussis containing vaccines is achieved (41). Another relevant concept associated with the utilization of Tdap vaccine in pregnancy is the potential blunting of infant immune responses to active immunization when high concentrations of maternal antibodies are present. This has been observed and documented for various antigens in the pertussis vaccines, including pertussis toxin, filamentous hemagglutinin, and pertactin, but relatively lower concentrations of vaccine-specific antibodies in infants after primary vaccination have not been associated with increased incidence or severity of pertussis disease in infants of vaccinated mothers, and preservation of priming and memory immune responses has been documented (42–45). Furthermore, the safety and effectiveness of the Tdap maternal immunization program have been demonstrated in the US and the UK, supporting continuation of this intervention in these countries (23–26). Similar programs are in place now in Latin America and other countries and regions with high burden of pertussis disease.