Vaccine Hesitancy: In Search of the Risk Communication Comfort Zone

"Parents live within and have to navigate an increasingly complex, noisy mediascape in which conflicting claims about vaccines and VPDs [vaccine-preventable diseases] compete for attention and thus shape their affective environment....[H]ow do we talk about vaccine hesitancy, to what do we attribute this phenomenon, and what solutions do we consider?"

While the number of Canadian parents who hold strident anti-vaccine beliefs and refuse to vaccinate their children is generally low (fewer than 3%), increasing numbers of parents (up to 35% in Canada) fall somewhere along a spectrum of beliefs and behaviours that can be termed "vaccine hesitant" (VH). In an effort to assess parental understanding of childhood immunisations, identify sources of information that they trust for vaccine-related content, assess where parents with young children stand on the key issues in the public debate about vaccination, and decipher which risk communication messages are most effective for influencing the behaviours of VH parents, the researchers conducted a national (Canada) online survey of 1,000 parents of children aged 5 and younger regarding immunisation-related decision-making, and focusing specifically on the measles, mumps, and rubella (MMR) vaccine. The survey instrument, administered in November 2015, included 25 questions organised into 4 major categories: perceptions about vaccines and vaccination; views on the public debate about vaccines and vaccine-preventable disease (VPD); information-seeking needs and practices, including media usage and trust in institutional sources; and communication strategies.

Approximately 92% of the Canadian parents surveyed consider vaccines safe and effective, and trust doctors and public health officials to provide timely and credible vaccine-related information. Among the 3.9% of survey respondents who indicated that they have intentionally chosen to not vaccinate children, the major concerns given were fears about the possibility of serious adverse reactions (25%) and skepticism about vaccine effectiveness (11%). Nearly 17% of parents consider vaccination "less important today than in the past", which the researchers say should be a source of concern given the resurgence of VPDs such as measles. Furthermore, a number of those surveyed either believe or are uncertain about whether there is a link between vaccines and autism (28%), worry that vaccines might seriously harm their children (27%), or believe the pharmaceutical industry is behind the push for mandatory immunisation (33%). "This indicates that even among parents who vaccinate, some of the most dangerous claims raised by the anti-vaccination movement - vaccines will injure your child and can cause autism - have achieved a concerning degree of resonance." Even though more than 90% of parents have had their kids vaccinated, 44% agreed that vaccination should still be a matter of parental choice.

The researchers asked parents an open-ended question: Which media sources do you most use for health news and information? For the majority of respondents (57%), online news and information sources (e.g., Google, social media, websites, etc.) are their preferred source for health news and information, followed by television or radio (29%). They also posed a series of situational questions designed to understand where parents would go first and most often for information and guidance if an outbreak of VPD were to pose a risk to their community. Despite the expectation that they would turn to Twitter or Facebook, only 14% of respondents indicated they would consult social media for breaking news and information if an outbreak of VPD were to threaten their communities. Instead, the website of major news organisations was the overwhelming top choice (33%), followed by official government websites (24%) and television stations (19%). The results show that the 3 most trusted sources for health information overall are physicians (89% trust), public health officials (83% trust), and academics (77% trust). Levels of trust in physicians, public health authorities, and academics were much higher among vaccinators than non-vaccinators: Approximately 90% of parents whose children have been vaccinated agreed that these sources can be "trusted to do what is right", compared to only 6% who disagreed. Roughly equal numbers of parents expressed trust and distrust in the news media (46 trust, 47 do not trust). "This finding is intriguing given how many of our respondents stated they would rely on media outlets as their main source of information during an outbreak event."

As noted here, health officials have used numerous approaches to persuade parents who do not vaccinate their children to change their views and behaviours and to reinforce positive vaccine behaviour among those who already do. While the study did not involve experimental testing of risk communication interventions, the researchers did ask participating parents to reflect on messages that public health officials often use to persuade those who are VH, and to indicate which, if any, they feel work best at increasing vaccine uptake among this group (see Table 1). The majority of respondents believed that all of the suggested messages, with the exception of shaming, are likely to be effective in persuading parents to have their children vaccinated. While almost two-thirds of the parents agreed with the statement, "parents who do not have their children immunized (except in cases involving medical exemptions) are irresponsible," nearly as many (64%) believed that this message would be unlikely to change the immunisation behaviours of other parents. The messages that respondents overall felt would most likely work with VH parents were those that emphasised the scientific evidence showing that vaccines are safe and effective (47%), followed by messages about the likelihood of catching a serious childhood illness without vaccine protection (40%) and those which vividly detail the effects of childhood diseases (37%). Among the small number of parents who self-identified as holding anti-vaccine beliefs, the only message that showed any hope of effectively persuading parents like them was, "provide positive encouragement and emphasize that vaccines are strongly recommended, but ultimately the decision is theirs to make" (77%). All other messages generated very strong negative reactions for non-vaccinating parents, indicating they would all be unlikely to ameliorate their hesitant beliefs and behaviours.

Parents reported high levels of support for pro-vaccine messaging that has been demonstrated in previous research to have little to no positive impact on behaviour change, and may even be counterproductive. Namely, "officials often resort to scare tactics and have occasion to use dramatic and vivid imagery to frighten or shame parents into having their children vaccinated. Images of sick children may effectively provoke fear, worry, and other emotions that can be persuasive. Yet, the use of emotionally evocative images may also strengthen beliefs in a vaccine/autism link among a core group of parents, while dramatic narratives that describe the risks to infants of under-immunization can increase self-reported beliefs about serious side effects of vaccines....The results of our research illustrate a potential disconnect between what parents of young children believe will be effective in persuading parents who are vaccine hesitant with what the available experimental research already tells us: more evidence, statistics and debunking strategies are the least likely to work."

These results point to "the value and importance of expressing empathy and compassion, and providing support and positive encouragement as a means for building trust with parents over the longer term, even if in the short term that does not lead to changes in immunization behaviour. Openness, dialogue, empathy, and respect are foundational values to ethical and effective risk communication....And while they might not yield an immediate shift in vaccination behaviours, they may, over the longer term, be our most effective protection against the wicked problem of vaccine hesitancy." [As explained earlier, a "wicked problem" is by its nature difficult to define, and the solutions for addressing such problems are often uncertain.]

In concluding, the researchers state that "[t]he data illustrate a combination of positive and troubling news for health communicators who are struggling to find the risk communication comfort zone that builds trust with hesitant parents while increasing vaccination rates." They also point out that, considering that most parents of young children still rely on traditional media and official government websites for timely and credible information about vaccines, particularly true during VPD outbreaks, "there are clearly important opportunities to use these extraordinary moments to reinforce positive messaging about the benefits of vaccination. Our data also show that parents place a high level of trust in government websites and expect or assume those sites to be regularly updated with reliable and timely information. Medical and public health officials working in government departments and agencies should pay special attention to this finding."

"Finally, parents report high levels of support for pro-vaccine messaging that emphasizes the science of vaccine safety and effectiveness, vividly depicts the consequences of disease, and debunks the myths and misinformation about vaccination. Future research should build on these results to test risk communication interventions with parents who occupy different standpoints along the vaccine hesitancy spectrum."