Measuring maternal Tdap and influenza vaccination rates: Comparison of two population-based methods

Pregnant women are routinely recommended to receive Tdap and influenza vaccines to prevent disease and complications among mothers and newborns. Monitoring population trends in maternal vaccination is important in order to evaluate the implementation of these recommendations and to identify pockets of need. We present two methods for measuring maternal vaccination among a state population and discuss the strengths and drawbacks of each method. First, we matched maternal information from records of Wisconsin births during 2013-2015 with maternal vaccination records in the Wisconsin Immunization Registry. Second, we used an all-payer health insurance claims database to identify Wisconsin women with deliveries during 2013-2015 and vaccinations received during pregnancy. Both methods produced similar trends and indicated a substantial increase in the percentage of women receiving Tdap during pregnancy, and lower vaccination rates among women who were Medicaid-insured. When available and timely, both methods are useful for monitoring maternal vaccination.