The Internet and Childhood Immunizations in Canada

Abstract

The Internet has been identified as a potential determinant in parental fears of immunization and subsequent sub-optimal immunization coverage. Facebook is the most popular social media (SM) platform in Canada, and as more people abandon landlines, this platform presents an opportunity for novel recruiting of vaccine hesitant (VH) parents. In this thesis, I investigate Facebook as a tool to recruit VH Canadian parents and examine the determinants of vaccine hesitancy among Canadian parents, including the influence of the Internet. The aims are to describe the methods in studying health behaviours via SM; investigate Facebook as a tool to recruit VH parents compared to Random digit dialing (RDD) methods and describe their determinants of vaccine hesitancy; quantify the association between seeking vaccination information online and parental perception of risk on childhood immunization; and assess the vaccination sentiments and themes in an unsolicited online debate on immunization. My systematic review revealed limited research using SM to study health behaviours and limitations in terms of representativeness and validity. Notwithstanding, SM was shown to be a useful tool in gathering data from targeted populations. I recruited Canadian parents by Facebook advertisements linked to an online survey on childhood immunization, and compared methodological parameters, key demographics, and vaccine hesitancy indicators to a population-based RDD sample of Canadian parents. Facebook recruitment yielded a large sample size within a short time period and at lower costs compared to RDD recruitment, and was superior in reaching VH mothers with young children. Lack of knowledge/awareness and misperceptions on the risk of immunization were the most reported determinants of vaccine hesitancy. Multivariate ordinal regression on both datasets revealed the odds of perceiving vaccines as less safe were significantly higher for parents who seek vaccination information online compared to parents who do not, after adjusting for income, Internet reliability, parental age and region. Analysis of online user-driven comments revealed the main themes in the anti-vaccination comments were inaccurate information and misperceptions on the risks of immunization. The majority of the pro-vaccination comments communicated the risks of not vaccinating, and judgments on the knowledge level of non-vaccinators. The results provide evidence to inform the development of targeted interventions on immunization.