Abstract

SAFETY AND IMMUNOGENICITY OF SEASONAL TRIVALENT INACTIVATED INFLUENZA VACCINES IN PREGNANT WOMEN

*Shighaf Ibrahim Mohammed and Ahmed B. AL-Rawe

Abstract

Pregnant women are at high risk for influenza virus infection and serious influenza-related complications and are recommended to receive inactivated influenza vaccine during the influenza season. Before 2009, although many attempts had been made to evaluate the efficacy of the vaccine, the strict evaluation had been difficult because of the presence of pre-existing antibodies and the antigenic mismatch between the vaccine strain and actual epidemic strain. Even within this context, however, the following findings have been identified: immunogenicity of the influenza vaccine in pregnant women is maintained; influenza vaccine is effective for protecting pregnant women from severe respiratory illness, and maternal antibodies are transferred to their fetuses via the placenta to protect the offspring from influenza infection and adverse infection outcomes. Beginning in 2009, when the A/H1N1pdm pandemic occurred, a more definitive evaluation of the efficacy of the vaccine from an immunological perspective was performed because vaccinated people had no or marginal pre-existing antibodies against the de novo A/H1N1pdm strain, and the formulation of the vaccine was monovalent at the time. It is suggested that influenza vaccination of pregnant women is an effective countermeasure to influenza virus infection is not only pregnant women, who constitute a high-risk group for influenza virus infection but also in their offspring.

Keywords: Influenza vaccines, pregnant women.