Vaccines were one of the great inventions of modern history. They helped stop America’s polio epidemic in the 1950s,
when it was paralyzing thousands and killing at least 3,000 a year. They have prevented the deaths of millions worldwide from diseases such as diphtheria, smallpox, measles and tetanus.
And yet many people are reluctant to get their shots or vaccinate their children.
A study published Wednesday concludes that using education campaigns, and simply trying to persuade people to get the shots, is far less effective than using indirect behavioral nudges.
The reason most people don’t get vaccinations for themselves or their children, the study found, isn’t because they need convincing but because they perceive inconveniences or obstacles.
The new report — published in the journal Psychological Science in the Public Interest — draws on hundreds of studies on psychology, behavioral science and vaccinations.
“When it comes to vaccines, I think we have this optimistic belief that just by telling people facts you can change their behavior,” said Noel Brewer, the study’s lead author. “But when was the last time someone told you one fact and suddenly you lost five pounds or started brushing your teeth?”
Their findings come at a time when a small but vocal contingent of anti-vaccination advocates have been spreading misinformation about vaccines, to the frustration of public health officials.
In recent years, health officials have struggled with pockets of vulnerability in the United States. For example, measles has made a return in recent years because parents in some areas have failed to vaccinate their children. Last year, researchers grappled with an especially worrying measles outbreak in Minnesota — the state's worst in decades.
In the face of such challenges, a common reaction among state health departments is to mount new education campaigns. But Wednesday's report suggests that focusing on education and persuasion usually fails to make much difference. Instead, the study concludes, doctors and health officials should focus on indirect behavior modification — actions like automatically scheduled vaccination appointments, phone and text reminders from doctors' offices and monetary incentives from employers.
In one real-world experiment cited in the report, a U.S. company that prompted its employees to name the date when they would get their next flu shot saw vaccinations rise by 1.5 percent. But when the company asked employees to name both a date and a specific time, the shots increased by 4 percent.
“Four percent may not mean that much, but in the world of vaccinations, it can be huge,” Brewer said.
In his own research in recent years, Brewer, a health and behavior scientist at the University of North Carolina, has been working with state health departments to increase vaccine rates for the sexually transmitted, cancer-causing human papillomavirus, or HPV, which remains low among U.S. adolescents.
Because HPV is sexually transmitted, some doctors are often hesitant or awkward in talking about it. In one study, Brewer found that doctors could increase vaccination rates simply by limiting their discussion of the HPV vaccine to brief, assertive statements.
The more time doctors spent talking about the vaccination, the study found, the more suspicious and worried the parents got about the vaccine. But when the doctors made short statements that present vaccinations as routine, vaccine rates increased by 5 percent.
“It's much more effective at visits to say the child is due for several vaccines and we'll take care of it at the end of the visit,” he said. “Of course, if parents have questions, then answer the question.”
Victor Dzau, president of the National Academy of Medicine, called Wednesday's study an important integration of research across the fields of psychology and vaccination.
In a separate essay accompanying the new report, Dzau said outbreaks like last year's Minnesota measles incident are especially frustrating because of how preventable they are.
“However, condemning individuals that fail to vaccinate themselves or their children will not solve the problem,” Dzau writes. “Psychology offers insight into why people engage in health behaviors including vaccination.”