“The Fourth International Neonatal and Maternal Immunization Symposium (INMIS 2017): Toward Integrating Maternal and Infant Immunization Programs“ has recently been published; it provides an overview of the proceedings of the 4th International Maternal and Neonatal Immunization Symposium held last year in Brussels, where presentations focused on the state-of-the-art research on the development and implementation of vaccines given during pregnancy for the protection of mothers and infants. All authors are IMPRINT network or board members.