When is maternal immunization ethically justified?

Maternal tetanus vaccination is already part of routine antenatal care and immunization campaigns in many countries, and it has played an important part in the reduction of maternal and neonatal tetanus. Additional vaccines that have been recommended for routine maternal immunization include those for influenza and pertussis, and other vaccines are being developed. If a safe and effective vaccine against Zika will become available, maternal immunization is a promising strategy to protect fetuses against microcephaly and other conditions that are caused by this virus.

Maternal immunization is however controversial since regulators, professionals, and the public are often reluctant to accept pharmaceutical interventions during pregnancy. So far, little attention has been given to the ethics of vaccination during pregnancy. The World Health Organization asked Wageningen philosopher Marcel Verweij to analyse the ethical aspects.

Pharmaceutical interventions during pregnancy

The general reluctance to use medical drugs and vaccines during pregnancy is fuelled by uncertainty about possible risk -- especially risks for the developing fetus. Pregnant women are almost always excluded from participation in clinical trials and therefore scientific knowledge about the safety of maternal immunization is limited. On the other hand, some vaccines (tetanus, pertussis, inactivated influenza) have been used regularly to protect women and so far this has not shown to create an increased risk of adverse effects in infants.

Precautionary principle

In their paper, Verweij and colleagues argue that a strict interpretation of the precautionary principle ('abstain from vaccination if there is uncertainty about safety') is counterproductive and allows unnecessary infection risks. A preferable precautionary approach is to set specific conditions for maternal immunization, notably the requirement that it is only applied in the case of concrete and severe infection risks for the pregnant women and her child.

Another key ethical principle for immunization is that it should not divert attention from other important health needs of women. In regions where antenatal care is still underdeveloped, strengthening such care for mother and child is a first priority. Maternal immunization can be part of that but this should depend on the needs of women in that specific region.

Ideally, maternal immunization is embedded in routine antenatal care

Active dialogue between pregnant women and health-care providers in the community could enhance the receptiveness of pregnant women to vaccination, and this dialogue is necessary to take into account concerns about the necessity and safety of maternal immunization. Taking the perspectives of women seriously contributes to the ethical justification and trustworthiness of the programme.

This study belongs to the Wageningen core theme A Global One Health, which is also one of the central research topics in the chair group Philosophy.