The situation is deadly serious: Europe is suffering a record number of measles cases – more than 82,000 people have been infected, and 72 have died, in 2018. Europe is not alone. The US says it’s experiencing the worst outbreak in years, the disease killed 900 people in Madagascar last year and is resurgent in the Philippines. Mumps cases are surging in Ireland, Panama is fighting a pertussis outbreak, and France is struggling to convince girls to vaccinate against cervical cancer⁽¹⁾. At the heart of the problem is ‘vaccine hesitancy’, a phenomenon as old as vaccines themselves. There has always been a spectrum of attitudes to vaccination ranging from enthusiastic supports and passive accepters, to those with genuine questions and virulent anti-vaxxers. There is growing concern that websites and social media channels are amplifying the problem. By spreading misinformation that is picked up by parents with questions, and creating an echo chamber for conspiracy theorists, these new tools have changed how we access and share information about vaccines. Research suggests the internet is influencing vaccine decisions⁽²⁾; that search engines are leading parents to dubious websites⁽³⁾; and that people who use Facebook and Twitter are less likely to vaccinate⁽⁴⁾.

Social media is part of the problem. But also part of the solution⁽⁵⁾.

In fact, it’s the only way forward if we are serious about going where the public is and addressing their concerns. Any other strategy cedes the playing field to anti-vaccine voices. One of the reasons we are in this mess is that the pro-vaccine majority was slow to embrace Facebook and Twitter, leaving anti-vaccine voices to fill the vacuum. While speaking up online may be intimidating for health professionals, academics, industry and international organisations, there is a growing body of research to light the way ahead, and plenty of good examples of how to advocate for vaccination online. It is vital that we draw on behavioural insights and the growing wealth of research in communication studies, psychology, anthropology and beyond . Information alone is not enough to change behaviour⁽⁷⁾. If it were, the ‘smoking kills’ labels of cigarette boxes would have put tobacco companies out of business long ago. One of the most basic things to get right is the platform. Research suggests that one of the reasons that evidence-based vaccine websites and social media channels are less successful than anti-vaccine competitors is that they are less engaging than their anti-vaccine competitors. And they are competitors. Websites with information about vaccines should be easy to find, attractive and should address questions readers have2. This can be done by actively replying to comments on social media and through FAQs, and by ensuring that websites are optimised to address social media keywords. And, like anti-vaccine websites, they need to mix science with storytelling.

Then there’s the message.

The intuitive responses to anti-vaccine messages online are typically to debunk myths or to attack the messenger. Both are fraught with risk and can backfire if not handled with care⁽⁸⁾⁽⁹⁾. Attacking those who disagree with us online never changes their minds; it’s also not a good look – public advocates should be concerned with third-party onlookers rather than hardened anti-vaccine voices. While it may be satisfying to try to ‘win’ an online argument with a stranger (or a bot), our goal should be to target the fence-sitters⁽¹⁰⁾ – the people whose minds have not been made up. Sometimes a dose of empathy is the best remedy⁽¹¹⁾. Tone matters too. Strongly rebutting claims about safety and risk can be counterproductive⁽¹²⁾. As for myth-busting, simply insisting that vaccines do not cause autism (which they don’t) sometimes just reminds people of the myth. If we want to change belief, we need to replace this (incorrect) ‘knowledge’ about autism with an alternative explanation. What do we know about the causes of autism and when it can be diagnosed? (Autism is a complex spectrum of conditions; changes in the brain occur long before a child has their MMR.)

We need evidence-based communication about evidence-based medicine.

Vaccine advocates are quick to highlight the evidence showing that vaccines are one of the greatest achievements of medical science and public health. Yet when it comes to communicating about vaccination, some still go with their gut instead of the evidence. Thankfully, this is changing fast. There is a growing body of randomised trials that tests vaccine communication interventions. For example, a team in the US tested a web-based social media intervention to see if it could improve vaccine acceptance among pregnant women⁽¹³⁾. It did. But even if it had not, it would still have been worthwhile. Others have tracked parental attitudes to vaccination in a randomised-controlled trial which saw some parents given online vaccine information while others were not. The attitudes of hesitant parents improved over time, according to the study.⁽¹⁴⁾ And there are ongoing experiments in the use of virtual reality interventions to deepen understanding of herd immunity and to change behaviour.

Some websites are already applying research in the real world.

This is a good time to be a vaccine advocate. Research on how to reach hesitant publics is growing; a new Life-Course Immunization Coalition has been launched in Europe; and the EU is launching a new coalition of vaccine advocates, planning to create an information hub and supporting a Joint Action on Vaccination. At ZN, we are playing our part too. We have been involved in Vaccines Today, an online hub of vaccine information since its foundation in 2010. The site, and its social media channels (Facebook, Twitter and YouTube), offers a mix of essential facts with engaging stories, videos and infographics. Not only does the website look good, its tone is less formal than some health authority websites, and it aims to answer frequently asked questions. By connecting with networks of vaccine champions online, it has expanded its reach – and boosted its search engine ranking. Search for ‘herd immunity’, for example, and you’ll find a Vaccines Today story and video. Key to the site’s success is a willingness to review what works. Its Editorial Board regularly reviews the most popular content to help refine its approach. Google and social media analytics offer a wealth of insights on how readers get to your website/social posts and how long they stay. By proactively doing more of what works, websites can improve their impact⁽¹⁵⁾. The site is also a member of the WHO’s Vaccine Safety Net network of trustworthy vaccine websites. Not only does this boost confidence in the site itself, it allows the project to pool analytics data with a huge network of similar sites from around the world. Together, they are building a picture of what people want to know about vaccines, and what kind of content attracts – and keeps – their interest. (Check out the VSN e-library of vaccine materials) ZN is driving another vaccine-related online project, the Influenza Hub. This fast-growing initiative is applying insights on the need to tailor campaigns to flu risk groups. Older people, pregnant women, those with chronic conditions, healthcare workers – they all require a unique message, delivered in a distinct tone and through the right mix of channels. The Flu 65+ campaign, for example, uses storytelling targeted at this age group – with a dose of humour for good measure. We’ve also trained health professionals in social media, equipping them with the skills – and confidence – to go online and engage. These experts are helping to turn the tide in their own countries and inspiring colleagues to join the fray.

What can you do?

Now is the moment to step up our advocacy, to network, to share resources, to conduct research and apply the results. The silent majority is speaking up – and finding that our voices are most powerful when we speak together. Join the online conversation – ZN will be with you all the way.