Influenza vaccination during pregnancy: a systematic review of effectiveness and adverse effects.

Abstract

Review question/objective Objectives: 1. To synthesise the best available evidence on the effectiveness of influenza vaccination during pregnancy, for pregnant women, her foetus and the child up to six months of age. 2. To synthesise the best available evidence on the types and frequency of adverse events for pregnant women, her foetus and the child up to six months of age, associated with influenza vaccination during pregnancy. Review questions: 1. What are the beneficial effects of influenza vaccination during pregnancy for pregnant women, her foetus and child up to six months of age? 2. What are the adverse effects of influenza vaccination during pregnancy for pregnant women, her foetus and child up to six months of age? Inclusion criteria Types of participants This study will focus on pregnant women with or without risk factors for complications from influenza infection, their unborn child that is being carried at the time of the vaccination, and children up to the age of 6 months. Types of intervention(s) Inactivated influenza vaccination, irrespective of antigenic configuration or adjuvant, administered via any route, any dose, to pregnant women of any trimester. Studies investigating the monovalent H1N1 vaccine will be assessed separately, as well as in combination with the standard trivalent vaccine. Comparator: Pregnant women not vaccinated against influenza. Types of outcomes •Number and severity of influenza and influenza-like episodes and hospitalisation from influenza for pregnant women and their infant less than six months. •Adverse effects for pregnant women, including but not limited to local reaction, fever, anaphylaxis, Guillain Barre Syndrome and maternal death. •Effects on the foetus, including but not limited to spontaneous abortion, stillbirth, premature birth, birth weight, foetal growth and congenital malformation. •Adverse effects of maternal immunisation on the infant up to six months of age. The case definition of influenza will be accepted as a collection of respiratory and systemic symptoms as defined by the author, and/or laboratory confirmed influenza using viral isolation and/or serology. Severity for the mother and infants will be assessed by hospitalisation and/or death, and/or severe disease such as pneumonia.