Acceptability of maternal immunization against influenza: the critical role of obstetricians

Introduction: Pregnant women and infants are at increased risk of vaccine-preventable complications due to influenza. In Switzerland, immunization was first recommended to all pregnant women in 2009. We assessed the acceptability of this recommendation and its determinants two seasons later. Methods: Women having delivered in the University Hospitals of Geneva during March 2011 were asked to fill in a questionnaire assessing their knowledge, beliefs and acceptability of influenza vaccination during pregnancy. Results: The questionnaire was completed by 261/323 (80%) women. Out of 261, 213 (82%) were aware of increased risks of influenza during pregnancy, and 119/261 (46%) knew that immunization was recommended during pregnancy. Only 110/261 (42%) recalled an immunization advise during their pregnancy and only 47/261 (18%) had been immunized. A direct recommendation was the main predictor of immunization, associated with a 107-fold increased likelihood of vaccination. Factors identified by multivariate analyses as independently associated with the likelihood of immunization were to have been recommended immunization by a private (OR 9.1) or hospital (OR 4.7) obstetrician rather than a midwife, to have no fear that immunization could cause preterm delivery (OR 0.3) and to have been immunized in previous years (OR 10.7). Conclusion: Two years after the recommendation of influenza immunization during pregnancy, most post-partum women recalled being neither recommended nor adequately informed about influenza vaccine and its safety. This identifies major gaps in awareness and/or communication in healthcare workers and suggests that improving immunization safety/efficacy awareness among obstetricians as the most likely method to improve flu immunization during pregnancy.