Assessments of vaccines for prenatal immunization

Abstract The strategy of prenatal maternal immunization to protect the pregnant woman and her infant was first used with tetanus toxoid, when it was recognized that young infants had very high rates of tetanus disease, well before the age when infant immunizations are provided. Antenatal immunization has now been recommended and utilized for additional vaccines to prevent infections in pregnancy and the young infant. There are several issues to consider which are unique to the strategy of antenatal immunization. The first is that immunization of the pregnant woman will affect the woman who receives the vaccine, her developing fetus, and the young infant for several months after delivery. For this discussion, we will consider the availability of data for the maternal–fetal–infant triad in 4 aspects: (1) Immunogenicity. (2) Safety. (3) Infant immunosuppression caused by passive maternal antibody. (4) Effectiveness. This discussion will review available data from vaccines for prevention of tetanus, pneumococcal, influenza and pertussis infections used in antenatal maternal immunization programs.