Reducing neonatal and thus under-five mortality and morbidity is a millennium development goal. Immunization in pregnancy is a promising approach to achieving this goal. It prevents infectious diseases and their complications by direct protection of the mothers as well as by indirect protection of the neonate by intrauterine antibody transfer from mother to child. Vaccines are available to prevent tetanus, influenza and pertussis during pregnancy and early life. They are now being systematically evaluated and increasingly recommended for global introduction as part of a immunization in pregnancy platform. Promising vaccines are in development for global use and include group B streptococcal (GBS) and respiratory syncytial virus (RSV) vaccines.
Introduction of these vaccines comes with tremendous potential benefit specifically for low and middle income countries (LMIC). However, there is much at stake when it comes to immunization of pregnant women. The safety of any product given to these primarily healthy pregnant women and their unborn babies is under specific professional and public scrutiny. Safety concerns related to immunization in pregnancy are unlikely to affect pregnancy immunization programs alone, particularly when the vaccines are also used in routine childhood and adult immunization programs, such as influenza and pertussis vaccines. Therefore, product or program specific safety issues need to be identified to appropriately assess the benefit-risk profile of these vaccines and their implementation programs and to protect the target population from unintended harm. On the other hand, unfounded public or professional concerns can jeopardize beneficial vaccine programs and need to be rapidly refuted based on rigorous science and globally well-coordinated decision making and communication.
The need for a globally concerted approach to actively monitor the safety of vaccines and pregnancy immunization programs is recognized by the WHO Global Vaccine Safety Blueprint, the strategic plan of the Global Vaccine Safety Initiative. A recent WHO consultation identified the currently fragmented research, the current lack of data comparability as well as the need to improve the quality of safety data to inform decision making and system strengthening.