Influenza immunization during pregnancy: Benefits for mother and infant (original) (raw)

2016, Human Vaccines & Immunotherapeutics

The serious consequences of influenza infection during pregnancy have been recognized for almost a century. In this article, we reviewed the evidence on the immunogenicity, safety and impact of maternal influenza immunization for both mother and child. After vaccination, pregnant women have similar protective titers of anti-influenza antibodies as non-pregnant women, demonstrating that pregnancy does not alter the trivalent inactivated influenza vaccine immune response. Studies from the United States, Europe and resource-constrained regions demonstrate that maternal vaccination is associated with increased anti-influenza antibody concentrations and protection in the newborn child as well as the immunized mother. Given the acceptable safety profile of influenza vaccines and the World Health Organization's recommendation for its use in pregnant women, maternal vaccination with inactivated influenza vaccine is a cost-effective approach to decrease influenza disease in newborns. However, as seen for influenza immunization in the elderly, the protective efficacy of current inactivated vaccines in protection of newborns is 50% at best, indicating significant room for vaccine improvement, which could potentially be achieved by addition of a safe and effective adjuvant. Thus, global deployment of inactivated influenza immunization during pregnancy would have substantial and measurable health benefits for mothers and their newborns. KEYWORDS adjuvant; influenza; immunization maternal and neonatal protection; Vaccine Pregnancy-associated immunological changes affecting vaccine responses Pregnancy is associated with immunological as well as biochemical, mechanical, hemodynamic changes in the mother, characterized by distinct immunological phases. 8-10 Implantation, placentation and the first and early second trimester of pregnancy are characterized by a pro-inflammatory environment. 11-13 Later, during the period of rapid fetal growth and development, hormonal changes and exposure to fetal antigens, maternal immunity moves toward a more anti-inflammatory setting. 14,15 These immunological phase changes are necessary