Faced with continuing outbreaks of influenza and other vaccine-preventable diseases, parents, educators, health-care providers, and policy makers around the world want to know how to be better at persuading people to get vaccinations. However, a comprehensive review of the scientific evidence, led by a University of North Carolina at Chapel Hill researcher, shows that the most effective interventions focus directly on shaping patients’ and parents’ behavior rather than trying to change their minds.
“A common myth is that it’s easy to persuade people to get vaccinated,” said Dr. Noel T. Brewer, professor of health behavior at the University of North Carolina Gillings School of Global Public Health and first author of the report. “But when was the last time hearing a fact one time led you to exercise regularly, lose weight or quit smoking? It’s the same for vaccination.”
The findings, published in Psychological Science in the Public Interest, a journal of the Association for Psychological Science, suggest that although vaccination campaigns commonly focus on changing people’s perceptions and attitudes about vaccines, there is little evidence to suggest that these campaigns are effective.
To understand factors that underlie vaccination behavior, Dr. Brewer and his co-authors integrate the latest findings from a variety of fields, including psychological science, public health, medicine, nursing, sociology and behavioral economics. Their report is accompanied by a commentary by Dr. Victor J. Dzau, president of the United States’ National Academy of Medicine.
Childhood vaccination generally has strong public support, but uptake varies across vaccines. Most infants in most countries receive recommended vaccines, while many adults forego vaccines such as the seasonal flu shot.
The best available data suggest that the percentage of people who actively refuse all vaccines is incredibly small and that neither vaccine refusal nor delay is on the rise. These findings contradict the media-fueled narrative that an increasing number of people reject immunizations. In reality, most people receive most vaccines in line with their doctors’ recommendations, with a few vaccines, such as influenza and HPV, showing uptake below target levels. Many people have favorable attitudes toward vaccination but do not always follow through to receive vaccines in full or on time.
The most effective interventions, the researchers find, are those that address various behavioral barriers, not those that aim to persuade patients of the importance of vaccination. Specifically, effective interventions build on favorable intentions in ways that:
“Many people just need a nudge,” Dr. Brewer said. “They have positive attitudes toward vaccines – or they have just a few questions that they want to ask their provider. Programs and policies should focus on these people who are already open to vaccination.”
In some cases, people encounter false or misleading information about vaccines. Research shows that the best way to correct this misinformation is to reiterate the facts clearly and in a way that fits with people’s intuitive beliefs.
These conclusions are supported by multiple sources of evidence, but the researchers note that much of the available research on vaccination behavior is limited in quality or quantity. Studies investigating vaccination attitudes and behavior over time are rare, and few studies examine the specific mechanisms or components that make for effective interventions.
Despite these limitations, cross-continent studies increasingly are converging upon some common findings. In general, these studies show that vaccine acceptance tends to be high, vaccine hesitancy exists around the world, and the factors that motivate vaccination are similar across countries.
Vaccination often is portrayed as a public health issue, but psychological science provides a lens for understanding the factors that motivate vaccination. The interventions that stand to have the greatest impact are those based on psychological theory and behavioral evidence.
“As [Dr.] Brewer and colleagues note, psychology offers insight into why people engage in health behaviors including vaccination,” Dr. Dzau wrote in his commentary. In publishing this report, he said, the authors “are performing a service to society by integrating the disconnected literature on psychological theories and vaccination, which can inform practical interventions to address the challenges of vaccination.”
Dr. Brewer’s co-authors on the report are Dr. Gretchen B. Chapman of Carnegie Mellon University, Dr. Alexander J. Rothman of the University of Minnesota, Dr. Julie Leask of the University of Sydney, and Dr. Allison Kempe of the University of Colorado Anschutz Medical Campus.