Measles Vaccination Attitudes Could Be Swayed by Outbreak Proximity

Proximity to a measles outbreak and level of trust in the US Centers for Disease Control and Prevention (CDC) may impact an individual’s attitude on vaccination, according to a new report published in Plos ONE.

Investigators from the University of Idaho surveyed approximately 1000 online responders in order to study both the effects of trust in governmental medical experts and how a person’s proximity to a recent disease outbreak might impact vaccine propensity. The questionnaire was broken into 3 sections, which asked about demographic information, respondents’ political leanings, and their vaccination attitudes. The questionnaire tapped in further to responders’ beliefs by asking how likely or unlikely they were to get vaccinated in 2 hypothetical scenarios: if there was no immediate risk of getting infected, and if there was an outbreak of the disease in their community.

The survey was distributed to a nationally representative sample of the US voting age population via a research firm. Responders completed the survey between January 25-27, 2017, although the study authors noted there were local measles outbreaks in 2016.

“We have found in some of our other research that people’s vaccination attitudes tend to be really influenced by their primary health care providers,” Florian Justwan, PhD, assistant professor of political science at the University of Idaho, and an author on the study, told Contagion®. “So, if people trust their family doctors and hear pro-vaccination messages there, this is likely going to influence their beliefs in this context. More generally, there is also some research that suggests that people are susceptible to various social influences when forming vaccination attitudes. The people you talk to and trust have a major effect on all sorts of social attitudes.”

The investigators broke their findings down into 3 main parts. Contrary to what they expected at the outset of the analysis, about two-thirds of responders gave the same answer to both hypothetical scenarios. They now believe that an individual’s proximity to a recent measles outbreak has no independent effect on that person’s vaccination attitudes.

“The most surprising thing that we learned is that proximity to a recent measles outbreak really only influences some people in their attitudes about vaccinations,” Justwan added. “Going into the project, we expected distance to matter for most people in our dataset. But as it turns out, it is really only those who distrust the medical establishment who are affected by how close they live to a recent outbreak.”

The study authors also were able to support other studies on this topic by concluding that trust in the CDC and other governmental medical institutions had a positive effect on an individual’s attitude towards measles vaccination.

Additionally, there appeared to be a significant interactive relationship between proximity to outbreak and trust in governmental medical experts, the investigators learned. Distance from a previous measles outbreak had no effect on vaccination attitudes for responders with medium or high levels of trust in such institutions, though proximity did matter for the subjects with little confidence or trust in governmental medical experts.

“In other words: low-trust individuals who live farther away from a recent measles outbreak harbor less favorable views about vaccination for this particular disease than low-trust respondents who live close to an affected area,” the study authors concluded. “This implies that citizens who are skeptical of the CDC and similar institutions base their vaccination decision-making to some degree on whether or not a given disease occurs in close vicinity to their community.”

Because the investigators utilized cross-sectional survey data, the authors were unable to assess how recency of a particular disease outbreak influenced attitudes. However, they suspect that both proximity and recency would impact an individual’s attitudes on vaccination.

The study team also said that distrust in governmental medical experts does not mean that primary care physicians, school nurses, or midwives are thought about the same way. They “therefore might be reliable resources for encouraging vaccination behavior…The news media could be a formidable agent in influencing health and vaccination attitudes, intentions, and behaviors,” the study authors added.