Influenza Vaccination During Pregnancy: Influenza Seasons 2002-2012, Vaccine Safety Datalink.

Introduction: Pregnant women are at risk for influenza-related complications and have been recommended for vaccination by the Advisory Committee on Immunization Practices (ACIP) since 1990. Annual rates of influenza coverage of pregnant women have been consistently low. The Vaccine Safety Datalink was used to assess influenza vaccine coverage over 10 consecutive years (2002-2012); assess patterns related to changes in ACIP recommendations; identify predictors of vaccination; and compare the results with those published by national U.S. surveys. Methods: Retrospective cohort study of 721,898 pregnancies conducted in 2014. Coverage rates were assessed for all pregnancies and for live births only. Multivariate regression analysis identified predictors associated with vaccination. Results: Coverage increased from 8.8% to 50.9% in 2002-2012. Seasonal coverage rates increased slowly following the 2004 ACIP influenza vaccine recommendation (to remove the first trimester restriction), but spiked significantly during the 2009 H1N1 influenza pandemic. Significant predictors of vaccination during pregnancy included older age; vaccination in a previous season; high-risk conditions in addition to pregnancy; pregnancy during either the 2004-2005 or 2009-2010 seasons; entering the influenza season after the first trimester of pregnancy; and a pregnancy with longer overlap with the influenza season (p < 0.001 for each). Conclusions: Influenza vaccination coverage among pregnant women increased between the 2002-2003 and 2011-2012 seasons, although it was still below the developmental Healthy People 2020 goal of 80%. The 2004 ACIP language change positively impacted first-trimester vaccination uptake. Vaccine Safety Datalink data estimates were consistent with U.S. estimates. (C) 2016 American Journal of Preventive Medicine. All rights reserved.