Immunogenicity and efficacy of influenza immunization during pregnancy: recent and ongoing studies.

Pregnant women and young infants are at increased risk from influenza. The World Health Organization and public health guidelines from Australia, Canada, and the United States recommend immunizing pregnant women with trivalent inactivated influenza vaccine. However, there are multiple barriers to the uptake of this recommendation. Additionally, current vaccines are not licensed for infants <6 months of age. Immunizing pregnant women would provide protection to both mothers and infants. The Bill & Melinda Gates Foundation (BMGF) and the National Institute of Allergy and Infectious Diseases (NIAID) are trying to address some of the issues associated with maternal immunization, which could be an effective intervention in both high- and low-resource settings to combat the significant maternal and infant morbidity and mortality due to influenza. BMGF and NIAID efforts are complementary to each other, focusing on evaluating the immunogenicity, efficacy, and safety of influenza vaccines during pregnancy; and the potential effect of maternal immunization on outcomes in infants in low-resource populations.