Sources and Perceived Credibility of Vaccine-Safety Information for Parents

Health Professionals as Sources of Vaccine-Safety Information

The source reported as being trusted a lot by the greatest proportion (27%) of our respondents was Web sites from doctor groups such as the American Academy of Pediatrics. Web sites from doctor groups were the only source trusted by >10% of the sample, which is consistent with the finding that physicians themselves were the source trusted a lot most often in our study. These findings highlight the importance of the trust parents place in their physician and also speaks to the potential strategies that might be used to disseminate evidence-based vaccine information. It would seem that ensuring a strong physician-parent relationship and using physicians in public roles (eg, public service announcements) would be appropriate to consider. At the least it will be essential that primary care physicians have the information and tools they need to effectively communicate issues of immunization safety to parents.

In this context, it is concerning that only 23% of the parents reported that they place a lot of trust in government vaccine experts/officials. These are some of the leading experts in our nation regarding immunization. Efforts to increase the level of public trust placed in these officials is integral to the dissemination efforts of accurate vaccine information. Further studies to determine the origin of the lack of trust and concrete steps that can be taken to address it should be conducted. In the meantime, it may be effective to have physician groups (working in concert with government officials) to be the lead voice regarding innovations in the immunization schedule, rather than government bodies themselves.

Non–Health Professionals as Sources of Vaccine-Safety Information

Although most parents place a lot of trust in their child(ren)'s physician,⁷ the proportion of parents who trust non–health professional sources for such information should not be discounted.⁸ Many non–health professional sources, increasingly celebrities, have taken it on themselves to play the role of experts regarding vaccine safety. These people have raised or propagated concerns regarding vaccines, usually on the basis of their personal perceptions and experiences, that often contradict health officials' and physicians' messages regarding vaccine safety. The results of our study reveal that 26% of parents placed at least some trust regarding vaccine-safety information with celebrities and 73% placed at least some trust in parents who believe that their child was harmed by a vaccine. Even if only a fraction of these parents receive, believe, and act on potential misinformation provided by such sources, there may be an adverse impact on immunization rates, the risk of vaccine-preventable illnesses for individual children, and public health.

Although many public health and medical professionals may not want to acknowledge the potential impact that celebrities and television shows have on parents' acceptance of vaccines, our results indicate the broad influence that these sources may have. Studies in the United Kingdom have revealed the impact of the media, politicians, and other nonprofessionals on public opinion regarding vaccine safety.⁹ Parents have reported difficulty in determining who to trust when safety information among sources is contradictory.⁹

The finding that only 74% of our respondents reported that they do not trust celebrities for vaccine-safety information is sobering. The role of celebrities in society is powerful, and the efforts of some to take on the role of expert in matters of public health is concerning. Celebrities are rarely trained in the ability to discern and critique the scientific literature, and they are not often expert in epidemiology, immunology, or toxicology. Nevertheless, network and cable news reporters have occasionally turned to celebrities to play this role and positioned them as experts as well. The public is little served by such efforts.

Strategies for information dissemination used by public health authorities have included positioning physician and/or public health authorities to counter celebrity efforts to discredit vaccines. One option for an alternative strategy for public health officials may be to engage in more proactive social marketing campaigns such as those described recently by Opel et al.¹⁰ Such efforts, combined with the use of newer media such as social-networking sites and Twitter, should be explored.

Of significant importance are the gender differences observed with regard to trust placed in sources for vaccine-safety information. Our finding that women are more likely than men to place trust in nonprofessional sources for vaccine-safety information should be noted by both public health officials and health care providers. Anecdotally, women are more likely than men to be the parent who brings the child to physician visits and more likely to be the parent to make health care decisions for the children. Vaccine information developed for parents should be designed with these findings in mind.

The finding that 40% of the Hispanic parents place a lot or some trust in celebrities should also be noted by public health officials. It is especially important given the fact that Hispanics are both the largest and the fastest-growing minority population in the United States. It is unclear from this study whether such celebrities are in the Spanish-language entertainment milieu or in the mainstream English-language medium. Further study should be undertaken to better understand this finding so that those who design public health information-dissemination strategies may take this into account. In contrast to our findings, other investigators have reported that black parents were more likely than white parents to have negative attitudes toward immunization and their child's health care provider.^11,12

Our findings also indicate that many parents are using, and place at least some trust in, a variety of Web sites for vaccine-safety information, including those from groups that oppose vaccines. This phenomenon was first noted by Wolfe et al,¹³ who found that vaccine-opposition Web sites rely heavily on emotional appeals to convey their messages. Indeed, almost as many parents place some trust in these Web sites as place trust in government Web sites. It seems that much can be done to better position and promote the Web sites of both government and physician groups as sources of evidence-based vaccine-safety information.

Our findings must be interpreted in light of some limitations. One potential limitation is response bias, given that the data were collected from a self-administered survey. We attempted to minimize response bias by inviting panel members with a description of the survey that did not mention immunization or vaccine safety and by including the vaccine-safety questions among questions on other unrelated topics. Another limitation is that sensitive questions about attitudes and behaviors were asked, but we believe that social-desirability bias was reduced by the fact that the respondents knew that their anonymity was ensured.