Web-based Social Media Intervention to Increase Vaccine Acceptance: A Randomized Controlled Trial

"Providing web-based vaccine information with social media applications during pregnancy can positively influence parental vaccine behaviors."

As part of the Colorado Vaccine Social Media study, researchers conducted a randomised controlled trial (RCT) to evaluate the effectiveness of Web-based vaccine information and social media interventions to increase vaccine acceptance. They pursed this investigation having observed that parents who are hesitant to vaccinate their children have complex information-seeking behaviours. Such parents are inclined to distrust traditional sources of scientific authority (e.g., physicians) and report using the internet to gather information on vaccines. Regardless of whether they are hesitant about childhood vaccination, parents who use the internet to educate themselves must sift through vast amounts of vaccine information. At the same time, social media may have the potential to allay parental vaccine concerns and improve immunisation rates. Could an expert-moderated, interactive vaccine website provide parents with a forum to voice their opinions, ask questions, and interact with other concerned parents and vaccine experts?

To explore this question, between September 2013 and July 2016, the researchers conducted a 3-arm, single-centre RCT. Participants were 1,093 pregnant women in Colorado, United States (US), randomly assigned (3:2:1) to a website with vaccine information and interactive social media components (VSM - 542 participants), a website with vaccine information (VI - 371 participants), or usual care (UC - 180 participants). At enrollment, 14.1% of the population was classified as vaccine hesitant on the basis of the Parent Attitudes and Childhood Vaccines (PACV) screener, and >62% of participants reported using the internet for health information at least weekly. Median vaccine hesitancy scores were 13, 17, and 15 for the VSM, VI, and UC arms, respectively (P = .44). During the course of the study, about 35% of the participants visited the website at least once (they were not required to do so), and hesitant participants were more likely to access the website than nonhesitant participants. All participants were members of the Kaiser Permanente Colorado (KPCO) health plan.

Separate interventions were developed for the VSM and VI arms. The theoretical basis for the VSM intervention was the multidirectional communication model, a social marketing strategy with 3 components. Component 1 is a standard, top-down process in which website developers create and present content to users. Component 2 is a bottom-up process that allows users to create content and interact with website developers. Component 3 is a side-to-side process in which users can interact with each other and share information. In contrast to the VSM intervention, the VI intervention only included the top-down component of the model.

In brief, the study team first developed the factual vaccine content, guided by the Health Belief Model and Theory of Planned Behaviour. They sought to present content that accurately represented the risks and benefits of vaccination, including information on vaccine-preventable diseases, vaccine safety, vaccine laws, the recommended immunisation schedule, vaccine ingredients, vaccine development, and basic immunology. Information was labeled and arranged into short, easy-to-read sections, guided by best practices in risk communication and website design. Sources of information were referenced and hyperlinked to help convey transparency and credibility. The information was focused on encouraging parents to receive recommended vaccines on time. Participants in the VSM and VI arms had access to the same base vaccine content.

In addition to vaccine content, participants in the VSM arm had access to social media technologies that included a blog, discussion forum, chat room, and "Ask a Question" portal through which participants could directly ask experts questions about vaccination. Experts included a paediatrician, a vaccine safety researcher, and a risk communication specialist. Each month, the research team created 1 to 2 blog posts covering topics such as new vaccine safety research, vaccine-preventable disease outbreaks, changes in immunisation policy, and the importance of adhering to the recommended immunisation schedule. Posts were either text or audio (podcasts), and participants could contribute comments and ask questions. Each month, they hosted online chat sessions in which participants could engage in real-time conversations with experts. Participants were also encouraged to submit questions privately through email; the team provided personalised responses within 2 business days. All participants in the VSM arm received monthly newsletters to encourage website participation and highlight new website content.

All interactive components were moderated. Responses to comments and questions adhered to a consistent communication framework designed to convey dedication, expertise, and honesty. Intervention details (including the Hoffman's template for intervention description and replication checklist and guide and screenshots of the intervention websites) are included in the Supplemental Information.

Vaccination was assessed in infants of 888 participants from birth to age 200 days. (There were 99 hesitant participants in the analysis.) The primary outcome was days undervaccinated, measured as a continuous and dichotomous variable. A nonparametric rank-based analysis revealed that mean ranks for days undervaccinated were significantly lower in the VSM arm versus UC (P = .02) but not statistically different between the VI and UC (P = .08) or between VSM and VI arms (P = .63). The proportions of infants up to date on vaccines at age 200 days were 92.5, 91.3, and 86.6 in the VSM, VI, and UC arms, respectively. Infants in the VSM arm were more likely to be up to date than infants in the UC arm (odds ratio [OR] = 1.92; 95% confidence interval [CI], 1.07–3.47). Up-to-date status was not statistically different between VI and UC arms (OR = 1.62; 95% CI, 0.87–3.00) or between the VSM and VI arms (OR = 1.19, 95% CI, 0.70–2.03).

In short: "This RCT of a Web-based vaccine information and social media intervention had a positive impact on early childhood immunization. Pregnant women exposed to the VSM arm were more likely to vaccinate their infants on time than participants receiving UC. These results suggest that interactive, informational interventions administered outside of the physician's office can improve vaccine acceptance."

In the discussion section, the researchers elaborate on these findings, observing that:

• The timing of providing information does matter. Traditionally, vaccine information is provided to parents at well-child visits, which may not be early enough.
• Providing parents with information debunking vaccination falsehoods, such as the link between the measles, mumps, and rubella (MMR) vaccination and autism, can cause vaccine-hesitant parents to become more entrenched in their antivaccination views. However, in this study, it was shown that parental vaccine behaviours "can be positively influenced with a carefully timed, interactive, informational online resource administered by their health care organization".
• Although the VSM arm was designed to foster interaction between parents, parents who engaged in the social media applications were primarily interested in asking experts questions to address their specific vaccine concerns. They did not appear to be interested in forming an ongoing, vaccine-focused online community with other parents enrolled in the KPCO health plan.
• The VSM arm in the trial required significant resources to administer. A multidisciplinary, expert staff developed and reviewed new content, moderated chat room discussions, answered complicated questions related to the vaccination schedule, and addressed vaccine safety rumours as they surfaced. Therefore, it is unlikely that single clinicians or clinics would have the means to manage their own social media interventions. This could be mitigated by creating a national, centralised social media vaccine resource, but additional research would need to determine if it would be trusted and used by parents.
• Future applications of the interventions would have to stay abreast of emerging technologies (newer social media platforms, for instance) to continue to attract each new generation of parents.

In conclusion: "Web-based vaccine information with social media technologies can positively influence parental vaccine decisions. As a complement to routine well-child care, the information appears to be effective when presented to parents before their children are born."