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

"...deeply held beliefs in the community about influenza vaccine pose considerable communication challenges not likely surmounted with any single type of vaccine promotion message exposure."

The American College of Obstetricians and Gynecologists (ACOG) and the Advisory Committee on Immunization Practices (ACIP) recommend that pregnant women (and women who expect to be pregnant during the influenza season) receive the trivalent inactivated influenza vaccination. Yet, vaccination rates among racially and ethnically diverse pregnant women in the United States (US) are significantly lower than those of whites - despite persistently higher rates of morbidity, mortality, and hospitalisations due to influenza. In this context, the researchers sought to examine the effectiveness of persuasive communication interventions on influenza vaccination uptake among black/African American pregnant women in Atlanta, Georgia (GA), US.

As reported here, evidence suggests that misperceptions of influenza illness and immunisation influence the decision to vaccinate during pregnancy and that an array of factors, ranging from individual issues such as previous immunisation behaviour and attitudes toward vaccination to patient-provider vaccine communication and social network influences, may impact maternal vaccination decisions. A body of scientific literature points toward considerable influenza vaccine refusal and hesitancy among pregnant women.

Various forms of persuasion theory have been applied to immunisation decision-making and have therefore informed message framing strategies for pregnant women. One of these frameworks, the Elaboration Likelihood Model (ELM), suggests that influenza vaccination attitudes and beliefs are influenced by the interplay of variables as the recipient evaluates a message (e.g., "get immunised") and the message source (e.g., government, clinic, and/or physician recommending a vaccine). Application of the model would suggest that those who consider immunisation would face a risk-taking decision, and therefore may engage in careful thinking about immunisation information. This high degree of cognitive engagement (i.e., "high involvement" processing) would theoretically sustain counterpersuasion efforts (e.g., friends' and family's negative reactions) and would result in predicted behavioural outcomes (e.g., influenza immunisation). However, strong affective evaluations of information may also occur with emotional responses invoked, especially due to the incongruence such action poses to strongly held vaccine beliefs (i.e., cognitive dissonance) among racial and ethnic minorities.

Given the challenges associated with improving maternal immunisation coverage among this vulnerable population, this study tested 2 forms of targeted persuasive messaging models in comparison to generic influenza Vaccine Information Statements (VIS) developed by the Centers for Disease Control and Prevention (CDC). The researchers recruited black/African American pregnant women ages 18 to 50 years old from Atlanta, GA to participate in a prospective, randomised controlled trial (RCT) of influenza immunisation messaging conducted from January to April 2013.

The primary outcome for this study was uptake of influenza vaccine during pregnancy. Secondary outcomes included mother's intention to be vaccinated with influenza vaccine in a future pregnancy. Participants who reported not getting vaccinated with influenza vaccine were also asked to report reasons for not receiving the vaccine during pregnancy.

Eligible participants were randomised to 3 study arms:

1. Arm 1, comparison condition: The 34 women assigned to the VIS arm were given the material to read in the presence of a study team member.
2. Arm 2, affective messaging intervention: The 31 women assigned to the first intervention, a short film entitled "Pregnant Pause", were instructed to watch the 9-minute film viewed on a study iPad. This story centred on a black/African American pregnant woman's dilemma to get an influenza vaccine at 2 of her routine obstetrical visits. With normative and persuasive influences featured in the storyline, the film depicted physician-actors giving the woman their recommendation to obtain the influenza immunisation while acknowledging and discussing her concerns, including those of her mother, whose anti-vaccination beliefs ran counter to the recommendation (i.e., cognitive dissonance). Thus, the film utilised affective ELM cueing techniques (e.g., reliance on physician credibility for vaccine decision-making and addressing normative beliefs).
3. Arm 3, cognitive messaging intervention: The second intervention, also delivered on a study iPad, was entitled "Vaccines for a Healthy Pregnancy". This format encouraged the 30 participating women to watch short videos of actual physicians providing detailed, question-and-answer information on influenza vaccines. This information-dense format contained short modules covering topics such as the importance of these vaccines for both the mother and child, the severity of the diseases, how the vaccines work to protect pregnant women and their newborns, vaccine safety information, and information on the current ACIP recommendations. Thus, this interactive educational tutorial enabled women to choose the topic(s) they were most interested in and enabled them to complete each tutorial separately. Such a strategy is consistent with ELM "central route" processing that promotes issue-relevant thinking and evaluation of argument strength, emphasising the personal relevance of the topic.

At 30 days postpartum, all participants were contacted by study team staff by phone or email for a single vaccination outcome-oriented follow-up questionnaire. Subsequently, questionnaires were conducted by telephone during which participants were asked to describe general health of the mother and newborn child(ren), influenza immunisation status during pregnancy, future vaccination intentions, and attitudes and beliefs regarding vaccination. Chi-square and t tests evaluated group differences, and outcome intention-to-treat assessment utilised log-binomial regression models.

At baseline, most women (63%, n = 60) reported no receipt of seasonal influenza immunisation during the previous 5 years. They expressed a low likelihood (2.1 ± 2.8 on 0-10 scale) of obtaining influenza immunisation during their current pregnancy, and =39% of reported that they intended to be vaccinated with influenza vaccine in future pregnancies. At 30-days postpartum follow-up, influenza immunisation was low among all participants (7-13%) demonstrating no effect after a single exposure to either affective messaging (risk ratio (RR) = 1.10; 95% confidence interval (CI): 0.30-4.01) or cognitive messaging interventions (risk ratio (RR) = 0.57; 95% CI: 0.11-2.88). Women cited various reasons for not obtaining maternal influenza immunisations. These included concern about vaccine harm (47%, n = 40), low perceived influenza infection risk (31%, n = 26), and a history of immunisation nonreceipt (24%, n = 20).

The researchers suggest that the findings reflect the limitations associated with single exposure to maternal influenza immunisation persuasive messaging approaches on vaccine behaviour. For the population they studied, repeated influenza immunisation exposures may be warranted with alterations in message format, content, and relevance for coverage improvement. Put another way, the 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."

Specifically, they observe that, with 80% of the sample expressing that they consider their obstetrician (OB)/gynaecologist (GYN) to be their primary care physician yet only 5% of them ever having received a vaccine from their OB/GYN, there is an opportunity presented to shift the targeted technologically driven messages delivered by their intervention toward more tailored, practice-based messaging strategies in the future. This is especially relevant as merely 18% of the sample indicated "vaccine was not recommended to me by my doctor", which suggests that OB/GYN physicians in particular may also lack necessary communication skills to address vaccine reluctance, as it has not been a component of their formal or continuing education training. Thus, with provision of training for OB/GYNs and midlevel nursing staff on vaccine concerns cited by this population (i.e., potential vaccine-related harm, low perceived influenza risk, and overall adult vaccine refusal), practices and providers may be better equipped to address an immunisation service gap in women's healthcare, deliver more persuasive vaccine messages, and therefore normalise vaccination in the context of routine clinical care. In addition, the findings highlight the need for maintenance of maternal immunisation supply and onsite vaccination for patients to act upon the messages and recommendations they may be receiving prior to and within clinical encounters.

Thus, this study "points to the need for physician/provider training in vaccine communication and factors contributing to pregnant women's varying immunization decisions. By understanding the informational needs and concerns of pregnant women, in addition to their previous vaccination history, more effective messages may be developed and targeted to each group's unique needs. Such an approach to tailored messaging, combined with provider recommendation and ease of access, may ultimately lead to greater acceptance and uptake of immunization during pregnancy."