August 15, 2017
This uncertainty is a major reason behind researchers’ hesitancy to expose pregnant women to newer vaccines. Women do indeed get vaccinated while pregnant—against the flu or tetanus, diphtheria, and pertussis (Tdap), for example. But “the overall safety for flu and Tdap vaccines was established in very large populations prior to being administered to pregnant women,” says August.
Some vaccines—such as the flu vaccine—included pregnant women in clinical trials. And, notably, pregnant women were included in Phase 3 trials for the new respiratory syncytial virus (RSV) vaccine that prevents a devastating, potentially fatal infection that targets infants.
But recommendations for vaccination during pregnancy are not always backed by clinical trials. “Historically, many of the recommendations have relied on observational data,” writes Johns Hopkins bioethicist Carleigh Krubiner in an email to The Scientist. She, along with August, is part of the working group who wrote the Wellcome Trust-funded guidelines for Zika vaccine administration in expectant moms. In these cases, pregnant women were either intentionally or unintentionally given vaccines, then mother and child were observed.
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.