Impact of a multi-component antenatal vaccine promotion package on improving knowledge, attitudes and beliefs about influenza and Tdap vaccination during pregnancy

ABSTRACT

Objective: Understanding whether interventions designed to improve antenatal vaccine uptake also change women's knowledge about vaccination is critical for improving vaccine coverage. This exploratory study evaluates the effectiveness of a multi-component influenza and tetanus, diphtheria, and acellular pertussis (Tdap) vaccine promotion package on improving women's knowledge, attitudes and beliefs toward antenatal vaccination. Study Design: In 2012/2013 a cluster-randomized trial was conducted to test the effectiveness of a vaccine promotion package on improving antenatal vaccine coverage. Participants included 325 unvaccinated pregnant women from 11 obstetric practices in Georgia. Eleven health beliefs measures were assessed at baseline and 2–3 months post-partum. Outcomes were differences in proportions of women citing favorable responses to each measure between study groups at follow-up. Results: Women enrolled in their third trimester had a higher probability of asking family members to vaccinate to protect the infant if they were in the intervention group versus the control group (36% vs. 22%; risk ratio [RR] = 1.65, 95% confidence interval [CI]: 1.21, 2.26). A similar association was not observed among women enrolled before their third trimester (39% vs. 44%; RR = 0.93, 95% CI: 0.50, 1.73). There were no other significant differences at follow-up between study groups. Conclusions: While exposure to the intervention package may have raised awareness that vaccinating close contacts can protect an infant, there is little evidence that the package changed women's attitudes and beliefs toward antenatal vaccination. Future research should ensure adequate exposure to the intervention and consider study design aspects including power to assess changes in secondary outcomes, discriminatory power of response options, and social desirability bias. This study is registered with clinicaltrials.gov, study ID NCT01761799.

KEYWORDS:

• antenatal vaccination
• influenza
• randomized clinical trial
• Tdap

Disclosure of potential conflicts of interest

Allison Chamberlain, Katherine Seib, Eli Rosenberg, Paula Frew, Marielysse Cortés, Ellen Whitney, Ruth Berkelman, Walter Orenstein and Saad Omer have no conflicts of interest to report. Kevin Ault has acted as a consultant on maternal immunization with the Centers for Disease Control and Prevention (CDC), the National Institute of Allergy and Infectious Diseases (NIAID), and the American College of Obstetricians and Gynecologists (ACOG). Dr. Ault serves on a data safety and monitoring committee with Novartis and is the site principal investigator for a clinical trial sponsored by Novavax.

Acknowledgments

We would like to thank the 11 obstetric practices who participated in this study as well as all the study participants. We also thank the Emory graduate research assistants who assisted with this study.

Funding

This study was supported by a grant from the Centers for Disease Control and Prevention (CDC), grant # 5P01TP000300, to the Emory Preparedness and Emergency Response Research Center, Emory University, Atlanta, GA. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the CDC. The CDC had no involvement in the study design; in the collection, analysis and interpretation of the data; in writing this manuscript, and in the decision to submit this manuscript for publication.