Introduction: Pregnant women have a higher risk of serious complications from influenza than non-pregnant women of reproductive age. This increased risk has been noted both during pandemic and inter-pandemic influenza seasons. However, although vaccination against flu is recommended at any trimesters by international and national policies, vaccine coverage remains low in pregnant women, possibly due to patient and healthcare providers’ concern about the safety of the vaccine.

Areas covered: This review addresses the effectiveness and safety of seasonal and adjuvanted and non-adjuvanted pandemic 2009 A/H1N1 influenza vaccine.

Expert opinion: Available data suggest no evidence of an increased risk for any adverse event for both mothers and fetuses after vaccination against flu during pregnancy. These results are important when considering the potential of maternal immunization against flu as a public health intervention to protect both the mother and her infant against serious infectious disease.

Keywords: adjuvant, effectiveness, fetus, newborn, pandemic 2009 A/H1N1 influenza, pregnancy, safety, seasonal influenza, vaccination, vaccine