In 2017, the prevalence of measles worldwide spiked by 30% compared to the previous year.
The leap — alarming in itself — is just one symptom of a malaise that the World Health Organisation has named among the 10 most pressing health concerns of 2019. “Vaccine hesitancy”, defined as the unwillingness to accept vaccinations against diseases even when they are available, is on the rise.
We now know for sure that vaccines prevent disease without causing autism or the other side-effects that anti-vaxxers claim. Yet old suspicions are creeping back into the public consciousness, often via social media.
According to some experts, the public health community is offering only facts and statistics — while many sceptical parents might respond better to sensitive discussion and reassurance. The fight against anti-vaxx sentiment might need new tools to tackle resurgent conspiracies. But could behavioural science turn the tide?
Since the advent of vaccinations in 1796, few other medical innovations have enjoyed quite such clear, quantifiable successes.
Smallpox, responsible for an estimated 300 million deaths in the 20th century, was declared eradicated in 1980. And polio — once a scourge of countries across the world — has been almost obliterated by global vaccination campaigns.
According to Mike Coleman, director of Common Thread, an organisation working to integrate behavioural science into public health programs, that success might have bred complacency.
“On an everyday basis people don’t see disease so much anymore, and maybe it’s not as tangible as it once was,” he said.
“Vaccine hesitancy is not ‘accept’ or ‘don’t accept’ — it’s a continuum,” Coleman continued.
Some people oppose vaccination thanks to unfounded health fears. Others assume their children can manage without. But the specific reasons for refusing or delaying vaccination differ from person to person. “Reducing it to a dichotomy doesn’t take account of all the complexity in between,” said Coleman.
Decision-making is a complex process, involving weighing up competing priorities, costs, beliefs and time constraints. Humans might be rational animals, but not all of our decisions are reasoned.
In Pakistan, one of the three countries where polio is yet to be eradicated, the long struggle against the disease holds lessons for tackling scepticism about vaccines elsewhere. The disease is now down to the tens of cases per year; a significant achievement in a region with constant migration, pressing security concerns, and limited health coverage in rural areas.
In Pakistan, health workers have learned the importance of understanding behaviour change and decision making as it really happens — not as a purely rational model of human behaviour would dictate.
According to Dr Rana Safdar, Coordinator of the National Emergency Operation Center for Polio Eradication in Pakistan, public health campaigns often try to counter people’s perceived objections to vaccination — rather than addressing the concerns they actually hold.
“Whenever anyone talks about misconceptions relating to polio vaccination [in Pakistan], people think that [religious reasons are] the major issue,” he said, but an extensive program of household surveys showed otherwise.
Only 5% of Pakistan’s population in need of polio vaccination expresses some form of vaccine hesitancy, and only 0.3% actually refuse to be vaccinated after discussions with health workers.
Of that 0.3%, religious concerns are the deciding factor for only a tiny minority of people — around 3.8% of refusals. Much more prevalent are concerns around the quality of vaccine, which people fear is low because the vaccine is offered free-of-charge.
In that instance, religious reassurances are of little use when explanations of the vaccine’s quality control are what’s needed.
Realities on the ground
A second factor often underplayed in discussions of vaccine hesitancy is the various barriers that exist to delivery. When resources or infrastructure are scarce, it is even more important to optimise delivery based on how people are actually using your services.
“There can be a tendency to deliver things in a very direct manner,” said Coleman. “If the vaccine is available, and the clinic has it and the staff are trained then the parents should want it and demand it. That’s not always the case.”
In Pakistan, for example, not every community has a central health centre where parents can take their children, and home vaccination efforts were failing because of timing issues and gender issues.
By only offering vaccines during the day, vaccinators were arriving when the male head of the household — often the decision maker — was out of the home and unable to grant permission.
And while the program developers assumed that men would be more trusted to deliver the vaccine due to prevalent gender inequality in the country, household surveys revealed a clear preference for female vaccinators.
But perhaps the greatest sea-change in vaccination efforts came when project implementers began to reframe the project not as an international disease eradication effort but as a series of community-based programs, delivered by people recruited from the community.
According to Mike Coleman, what works in Pakistan won’t necessarily work elsewhere, but the need to understand and engage sensitively with vaccine sceptics is true anywhere, in the global north or south.
Despite the ire with which public debates between vaccine proponents and sceptics often take place, Coleman’s work suggests two important routes through the impasse.
“There’s growing understanding of the critical importance of acknowledgement and correction,” Coleman said.
Dismissing concerns out of hand or providing citations of scientific papers is unlikely to convince someone sceptical of vaccines.
But engaging in a meaningful dialogue where concerns are listened to and sounded out collaboratively can make a much more meaningful difference.
“There’s a tendency to over-rely on fact,” said Coleman, “that doesn’t take into account the complexity of how we measure risk and take decisions.”
A second approach would seek to put an idea common across the world at the centre of efforts to engage hesitant parents. Tapping into a parent’s love, not berating their purported ignorance, could be the human catalyst to speed up eradication efforts.
“Parents want what’s best for their child no matter where you are. Their heart is in the right place. They want to be sure that vaccines are safe, that the people delivering the vaccine are trusted, that side effects are minimal and won’t harm their child, and that the vaccine is effective.”—Edward Siddons
(Picture credit: Flickr/Sanofi Pasteur)