Background: Evidence regarding the effectiveness and safety of the influenza vaccine during pregnancy is crucial for healthcare providers' decision-making processes. This study aims to review the existing evidence on the effectiveness and safety of influenza vaccination in pregnant women and its impact on pregnancy outcomes.
Materials and Methods: In this overview, two independent researchers selected articles reporting on the effectiveness and safety of influenza vaccination for pregnant women and their fetuses. The search was conducted across multiple databases, including Scopus, EMBASE, Cochrane Library, Web of Science, CINAHL, Medline, and Google Scholar, without any time restrictions up to January 2023.
Results: Based on the available evidence, pregnant women are at a higher risk of serious illness from influenza compared to non-pregnant women. The influenza vaccine is the most effective way to protect both pregnant women and their infants against influenza, as well as to prevent potential complications associated with the virus during pregnancy. Vaccination during pregnancy is safe, cost-effective, and provides neonatal protection against influenza through the partial transplacental transfer of protective antibodies. There is no evidence linking influenza vaccination administered at any stage of pregnancy to adverse outcomes such as premature birth, spontaneous abortion, congenital anomalies, shortened gestation, gestational diabetes, chorioamnionitis, gestational hypertensive disorders, or fetal death. Furthermore, influenza vaccination during pregnancy has been shown to reduce the risk of pre-delivery hospitalization due to influenza-like illness by approximately 39%.
Conclusion: The administration of an inactivated influenza vaccine during pregnancy is safe for both the mother and the fetus and is recommended for all pregnant women. There is no evidence linking influenza vaccination to maternal complications or adverse fetal outcomes.