Safety of Inactivated Vaccines in Pregnancy

Newborns may suffer of severe infections and the best defense against pathogens is given by the passage of maternal antibodies through the placenta and later by breastfeeding. A greater amount of circulating antibodies in the mother is often related to a higher value in the blood of the child, thus maternal immunization could be a tool for preventing neonatal infections. Most trials were performed in developing countries, where the success of vaccinating pregnant women against tetanus led to the acceptance of maternal immunization. Thereafter, trials performed with different inactivated vaccines demonstrated the effectiveness of the intervention without showing important safety problems. In industrialized countries, only few trials were performed and no conclusive evidence of long term safety is available for most proposed vaccines. Even when safety and efficacy have been clearly demonstrated, like influenza vaccination, the coverage is low. Vaccination in pregnancy is a promising tool for the protection of both woman and child, but more data are needed before this practice can be widely accepted in all industrialized countries.