Assessing the safety of influenza immunization during pregnancy: the Vaccine Safety Datalink.

The influenza vaccine can reduce maternal and neonatal morbidity and mortality and thus is recommended for all pregnant women. However, concerns regarding safety of influenza vaccine remain a barrier to vaccination. We describe ongoing analyses of influenza vaccine safety during pregnancy within the Vaccine Safety Datalink that includes the evaluation of acute events, adverse pregnancy and birth outcomes, and congenital anomalies. In addition, we highlight unique challenges and strategies for the study of vaccine safety among pregnant women with the use of large linked databases.