A Randomized Trial of Maternal Influenza Immunization Decision-Making: A Test of Persuasive Messaging Models

Theoretical Background and research questions/hypothesis: Influenza-related infections are a significant contributor to population morbidity and mortality on a global and national scale.  Even with the substantial body of scientific evidence documenting the safety of influenza vaccine for pregnant women, and the corresponding risk of severe influenza-related complications including low infant birth weight and preterm birth outcomes, vaccination among pregnant women remains suboptimal to Healthy People 2020 goals. Overall, female adult influenza vaccination rates have remained historically low, and particularly within minority communities. Thus, this research sought to examine the effectiveness of persuasive communication interventions on influenza vaccination uptake among black/African American pregnant women.

Methods: We recruited black/African American pregnant women ages 18 to 50 years from Atlanta, GA to participate in a prospective, randomized controlled trial of influenza immunization messaging conducted from January to April 2013. Eligible participants were randomized to three study arms. We conducted follow-up questionnaires on influenza immunization at 30-days post-partum with all groups. Chi-square and t tests evaluated group differences, and outcome intention-to-treat assessment utilized log-binomial regression models.

Results: Of the 106 enrolled, 95 women completed the study (90% retention), of which 31 were randomly assigned to affective messaging intervention (“Pregnant Pause” video), 30 to cognitive messaging intervention (“Vaccines for a Healthy Pregnancy” video), and 34 to a comparison condition (receipt of the Influenza Vaccine Information Statement). The three groups were balanced on baseline demographic characteristics and reported health behaviors.  At baseline, most women (63%, n=60) reported no receipt of seasonal influenza immunization during the previous five years. They expressed a low likelihood (2.1±2.8 on 0-10 scale) of obtaining influenza immunization during their current pregnancy. At 30-days postpartum follow-up, influenza immunization was low among all participants (7-13%) demonstrating no effect after a single exposure to either affective messaging (RR=1.10; 95% CI: 0.30-4.01) or cognitive messaging interventions (RR=0.57; 95% CI: 0.11-2.88). Women cited various reasons for not obtaining maternal influenza immunizations. These included concern about vaccine harm (47%, n=40), low perceived influenza infection risk (31%, n=26), and a history of immunization nonreceipt (24%, n=20).

Conclusions: The findings reflect the limitations associated with a single exposure to varying maternal influenza immunization message approaches on vaccine behavior. For this population, repeated influenza immunization exposures may be warranted with alterations in message format, content, and relevance for coverage improvement. 

Implications for research and/or practice:  Findings reinforce the notion that maternal immunization is not likely to shift without effective, repeated messaging that normalizes vaccination as a women’s and infant health protection issue. Study findings imply there may be a unique opportunity to further explore tailored practice-based messaging strategies.