In Reply We appreciate the opportunity to respond to Zimmerman and colleagues. While we recognize the ultimate success of the rubella campaign, we believe its lessons inform an approach that will better serve women and children in the context of Zika vaccination.
First, the authors argue that caution was an “appropriate” means to avoid the theoretical possibility of vaccine-induced teratogenesis, given limited safety data. We do not contest the relevance of this consideration, but offer that the narrow focus on it came at a cost. Ramifications included the unanticipated paradoxical effect, but also the ongoing exposure of unvaccinated pregnant women to a known teratogen, wild-type rubella virus. Infection before 12 weeks’ gestation is associated with a 90% risk of congenital rubella syndrome.1 This reflects a tendency—common in pregnancy—to notice the risks of medical intervention over the risks of nonintervention.2 Rubella reminds us that what we fear most may not be the only, nor the greatest, threat.