Ask the Experts: Vaccine confidence in the ‘post-truth’ world


In line with World Immunization Week, we’ve brought together a panel of experts to discuss the issues surrounding vaccine confidence in a ‘post-truth’ world. How does vaccine hesitancy differ across the globe? How are new technologies such as social media impacting vaccine confidence? And what can be done to help improve vaccine uptake?

We take a look at these questions and more with thoughts from David Salisbury (Chatham House, London, UK), Paolo Bonanni (University of Florence, Italy), Heidi Larson (London School of Hygiene and Tropical Medicine, UK) and Bruce Gellin (President of Global Immunization at the Sabin Vaccine Institute, DC, USA).

The challenges facing vaccination

What challenges do we face surrounding the uptake of vaccines and do these challenges differ across the globe?

Paolo Bonanni: One of the biggest challenges we face concerning vaccination is the worry that they cause adverse events and mistrust of the pharmaceutical industry. Compounding this is the communication around vaccines; in both the developed and the developing world there are conflicting messages on the risks and benefits.

Also, from time-to-time we have shortages of some vaccines and this can make the uptake more difficult. Recently, we have had shortages of the tetanus, hepatitis B and hepatitis A vaccines and when shortages occur it is a difficult situation to manage and ensure everyone is covered. For example, individuals who expect to be vaccinated at birth will have to wait, booster vaccinations are delayed etc. Finally, sometimes we have a lack of awareness of the importance of vaccines, not only the traditional vaccines but also the new vaccines such as HPV and rotavirus, which are very important.

Heidi Larson: The challenges facing vaccine uptake are highly varied depending on where you live. There are situations such as Venezuela and Syria where there has been either economic and political breakdowns or conflict, and that’s one category of why people are not getting vaccinated because the systems are broken or falling apart. Another issue is stock out, where there just aren’t enough vaccines.

There are also situations like the Philippines, where panic and concern about one vaccine, in this case the dengue vaccine, created a distrust in the system and vaccine uptake then dropped across all vaccines due to this breakdown in trust. Despite being totally different vaccines, they were being provided by the same government, the same health officials, and when trust in the system is lost one issue can affect another.

Moving to Europe, if you look at the example of measles over the past year, in the 83,000 cases of measles across Europe approximately 40% of them were in teenagers or young adults. These are individuals who missed their childhood vaccines – either their parents were concerned, or there were other reasons that they didn’t get their vaccine. This reflects that not just current gaps, but historic gaps need to be considered.

You also have situations where people hold alternative beliefs. There can be a functioning health system and access to plenty of information – as is the case of much of Europe – but then people can have either religious or philosophical views which affect vaccine acceptance. Currently, there’s a very strong global movement (not necessarily all connected but it’s emerging in multiple countries) around a ‘back to nature’ approach – anti-chemical, anti-inoculation, preferring natural foods, and individuals prioritizing what they consider a ‘natural’ immune system, sometimes endorsing measles and chicken pox ‘parties’ instead of taking the vaccine. This is high-risk behavior that’s driven by alternative beliefs, but there are also cases where there are individuals who are purposefully trying to use this uncertain environment to disrupt public acceptance of vaccines.

What implications can a lack of public trust for immunization programs and policies have?

David Salisbury: If the lack of trust leads to a lack of vaccination, then some individuals will not have lifesaving protection. Additionally, people whose intrinsic health conditions may make them unsuitable to be vaccinated are at high risk from respective vaccine preventable diseases. Imagine the tragedy of an immunosuppressed child being treated for leukemia who catches measles and dies.

Paolo Bonanni: Of course, this is not the same in all countries. Vaccine hesitancy is a world phenomenon, but the results and the way vaccine hesitancy impacts politics is different in every country, so there is no single solution to this very complex problem.

There are countries where there is a lack of trust in vaccines, for example, France. In France many of the population are very afraid of the side effects of vaccines, they do not trust that vaccines are totally safe and this is a problem that has a long tradition. In other countries there is more reliance on the public health institutions and their advice on vaccines. For example, in the UK the public health bodies such as Public Health England are very trusted, so when they say you must be vaccinated the population is compliant with that suggestion.

The implications are thus very related to the reliance of the people on the public authorities and whether the state or public authorities are perceived in a bad way. In recent years in Italy, despite the recommendation to get vaccinated many people have not been willing. However, there are also changes in this. In Italy there was a crisis and the vaccine coverage was dropping but a new law introduced the requirement to provide a vaccination certificate in order to be admitted at school, and this has changed the perception of vaccines. Today the environment is much more pro-vaccine than it was 4 or 5 years ago.

Is vaccination uptake facing new challenges in the age of social media?

Heidi Larson: It absolutely is. The emotions and anxieties are not new, we’ve had vaccine resistance for over 200 years, but previously it was more localized. What’s happening with social media is that anxieties and concerns can be shared more widely and travel faster. In addition, language is no longer a barrier as online translation tools are easily available.

So, I would say social media has amplified some of the concerns that were already there and, on top of this, there are also some people who didn’t have those concerns, and they’re now being are exposed to questions that they hadn’t thought about before. This exposure makes them start to wonder if they’re doing the right thing, so social media is also amplifying the audience.

Bruce Gellin: Vaccination’s biggest challenge is its success. As serious and life-threatening infections have become vaccine-preventable and no longer a common experience of every family, the need for vaccination may appear to be less compelling. But when outbreaks emerge, as is the situation now with outbreaks of measles in the United States and around the world, there is a renewed appreciation for the importance and value of vaccination.

Social norms and social networks matter. They always have. Social media has only amplified the power of social networks to shape behavior. One study showed that more than half of new parents are exposed to misinformation about vaccines on social media, so it’s understandable that they have questions. One notable effort to provide evidence and experience-informed information to parents is Seattle Mama Doc, a blog launched by pediatrician Dr. Wendy Sue Swanson at the Seattle Children’s Hospital (WA, USA) a decade ago when she realized “by wielding social media, moms and dads and activists were holding microphones, and doctors weren’t.”

Do you think ‘fake news’ impacts attitudes and behaviors around vaccination? Can more information combat this?

Bruce Gellin: Information is important. Vaccine recommendations are based on rich evidence of the effectiveness and safety of vaccination, and the impact on health and well-being has been overwhelming.

But information comes in many flavors and it’s not always easy to sort out facts from fallacy. We can help by directing them to sources that meet established criteria for good information practices. The World Health Organization has reviewed hundreds of web sites around the world and provides a list of those that meet this standard.

But information is not enough. Stories matter too. The ongoing measles outbreaks are the latest story…as contagion spreads largely among those who haven’t been vaccinated, we’re all watching how this plays out and the efforts being made to keep communities safe through vaccination.

Communicating vaccination

How can we effectively communicate the individual and community benefits of vaccines?

Bruce Gellin: We need to reinforce that vaccination IS the social norm. Parents want to be sure that they are making the best decision for their child and the swirl of information from many sources makes many hesitant as they weigh the options and seek ever more information and advice. We need to reinforce that vaccination is not only the right thing to do to protect their child, but it’s what most parents have also concluded. The benefits of vaccination are clear. Sadly, it may take more outbreaks to make equally clear the risks of choosing not to vaccinate.

Paolo Bonanni: As the medical world we need to engage in communication using tools like social media and the internet. In Italy we have created a presence on social media and websites that are dealing with vaccines in a scientific way, so I hope this helps the population to find reliable information and to be able to understand that vaccines are a fantastic tool for the health of everybody.

As healthcare workers, we are not trained to be able to communicate in the proper way but we must learn; both in universities but also as professionals we need to invest in communication abilities to make people understand the importance of vaccination.

Media outlets are often required to show ‘balance’ on controversial issues such as vaccine uptake – do you think this can lead to the promotion of misconceptions?

Bruce Gellin: If ‘required’ to show ‘balance’ then the balance should be proportional to the weight of the evidence. When I was a kid we were glued to the TV when watching launches into space from Cape Canaveral. Now we watch Space-X and hear about missions to the moon, Mars and beyond. But I can’t recall any media outlet compelled to include an interview with an expert from the Flat Earth Society. We know the risk of disease far outweighs any risk posed by immunization. That’s the story media outlets have a responsibility to tell.

David Salisbury: This is a deeply frustrating issue when journalists insist on showing both sides of an issue as if they were equally balanced. By running the alternate view, they give it credibility irrespective of its lack of validity. Whilst personal views do have to be given consideration, they should not be accepted as evidence that supports those views. I look forward to journalists saying, ‘Not everyone agrees, but I could not find a real expert in this field with the opposing view’.

How can we increase links between scientists and journalists to ensure accurate reporting? What training do both sides need?

Paolo Bonanni: I think you need to build continuous relationships and communication with journalists. For example, if a journalist doesn’t know you as a professional and asks you to comment on some bad vaccine-related news you have already lost your battle in a way because you are on the defensive. However, if you can build a relationship with the journalist then you can have a continuous discussion about the benefits of vaccination and if there is a crisis they can ask you about the risks but they won’t have a negative approach to the problem.

Sometimes it’s time consuming and it’s difficult to reply to everybody but just to be able to be contacted and to be relied on when there is a query or crisis is valuable. For example, if I were asked   about the hepatitis b vaccine being connected with multiple sclerosis, if I had a relationship with the journalist they can believe me when I say there is no relationship, this is fake news or incorrect information. So, you need to invest in those relationships with journalists, you must not be contacted only on the day something bad happens, but you must also be able to communicate with them in a moments without crisis when they can discuss the value of vaccination in general.

Bruce Gellin: I am glad you said both sides, because that’s an important consideration. We need local health experts volunteering to serve as trusted sources on immunization as well as journalists who are trained in science reporting and can recognize misinformation when they see it. What we didn’t have until now is a platform where journalists can directly reach immunization experts while working on a story.

Earlier this year, Sabin launched Immunization Advocates, which provides medical and media professionals with educational resources and connects journalists to health experts to help them report accurately on immunization. We are excited to expand this program to ensure fact-based reporting on immunization becomes the ‘new normal’ around the world.

How can scientists and healthcare professionals add their voice to the vaccine confidence conversation?

Bruce Gellin: Science doesn’t speak for itself. As groundbreaking as a vaccine research work may be, scientists today need to step out of the lab and get the significance of this work known to the public as fast as possible. If a peer-reviewed paper is released, consider promoting it on social channels or writing an op-ed to a local newspaper, promoting key data in relation to vaccine safety.

Medical training teaches us how important it is to listen to your patient to understand what they want and need to know. Parents value their healthcare professional’s experience and expertise and seek their guidance on immunization decisions. At the same time, healthcare professionals need to be empathetic and take time to have conversations about immunization. Unless parents get the advice they need from their child’s healthcare provider, they may well go elsewhere.

Advice and recommendations from healthcare professionals are the most important factor in vaccination decision-making. Not only is this important to their patients, but can also be important with the media and policy makers. I would encourage scientists and healthcare professionals to consider becoming an  Immunization Advocate to help journalists report fact-based information about vaccines.

And you don’t have to be a scientist or a doctor to help. If you’re a parent, get informed through trusted sources like the World Health Organization and talk to your friends about immunization. Your influence could help more than you know.

Research in vaccine hesitancy

What role can research play in understanding and addressing vaccine hesitancy?

Heidi Larson: I think research is incredibly important because typically health and public health bodies will develop their communication, outreach and information to patients and the community based on fact, based on what interventions and information is deemed important by the public health community. However, that’s not necessarily tuned into what the public’s questions, concerns or issues are.

So, I think it is really important to listen to communities and pay attention to what their questions, issues or priorities are. It helps to create a better sense of communication and trust with the public. Just the sheer act of asking for their views and finding out what people think is important because it allows people to feel like they’re being listened to, that they are engaged.

Scientific knowledge is inherently tentative and uncertain, nothing is ever ‘proven’ – do you think this language has an impact on vaccine confidence?

David Salisbury: For sure! Scientist speak: ‘Our study has failed to confirm an association between adverse event X and vaccine Y’. Consumer requirement: ‘This vaccine is safe and it does not cause adverse event X’.

What can be done to increase transparency in research? Is enough being done to ensure that data from vaccine trials are adequately reported not just within scientific communities but also to the public?

Paolo Bonanni: First, I think that data from trials should be available to both scientists and to the public. Sometimes it’s not easy to access to the data of the clinical trials that are not published, and there is a lack of publication of all data from clinical trials. In addition, I think there needs to also be some explanation of the data because if someone was not able to read the data, they might infer something that is not correct. So, one thing is to make the data from clinical trials easier to find and understand for anybody who wants to know because there is nothing to hide and I think transparency is always a good thing.

The other thing is regarding the relationship of the medical world with industry. I think we need to be transparent and to declare what our relationships are with industry, but I think it is impossible not to have relationships with those who produce vaccines because they have the know-how, they have the resources etc. Asking experts in vaccination not to have relationships with industry is like asking an engineer working on a bridge not to have relationships with the construction workers! It’s totally naturally that there is a strong connection between the know-how and the academia, those who have the idea to develop a vaccine and those who must bring the ideas to the real world, to scale up the production and to make the vaccine become an available product for everybody. There are some things that cannot be avoided – the important thing is that everything is transparent and is declared.

Vaccination, politics and awareness

With increasing vaccine hesitancy across Europe and the USA, should vaccination be compulsory?

David Salisbury: This seems to me to be a strategy of last resort as it can provoke strong contrary views. There is evidence that some countries achieve just as high coverage without compulsion as those that have it.

Paolo Bonanni: This is a difficult question because the matter of compulsory vaccination very much differs with the culture of every population. For example, in the UK when they tried to make vaccination compulsory there was a sort of revolution because for the UK population having something made compulsory by the state is unacceptable. However, this does not mean that the UK coverage is not one of the best in the world; although the population does not want compulsory vaccination, they comply with the suggestion to be vaccinated, making the suggestion of compulsory vaccination redundant.

However, in some other countries such as Italy, we now need to have compulsory vaccination – at least for a time – because there was such confusion about the truth regarding vaccination, its importance and its effectiveness and safety. I think of compulsory vaccination in Italy as a way for people to understand the truth and to realize that vaccination is good for not only your health but also for everybody else.

I see compulsory vaccination laws as an attempt to make vaccination become an accepted social norm. For example, nobody would say we should abolish the law to fasten your seatbelt when you are in your car, because it is for your own safety – this is an accepted norm. The same is true when you are at a construction site and you have to wear the helmet and protective clothing; nobody would say we have to abolish this, it is not only for your individual health, but it is also a social norm. So, I would see a compulsory vaccination law as an attempt to also make vaccination an accepted social norm, getting people to ask why shouldn’t I get vaccinated when this is for my own life, for my own health and to protect the others in the community?

Politically, do you think vaccine hesitancy and anti-vax movements are issues that are becoming increasingly important? What impact has politics had on vaccine confidence?

David Salisbury: Yes, to both. Whilst hesitancy is not a new phenomenon, the availability of linkages through social media creates opportunities for individuals to join networks of people outside their geographic proximity that share their views. Hesitant individuals may be prepared to change their hesitancy to vaccine acceptance whilst those with committed anti-vaccine beliefs are less likely to be influenceable. Vaccination has recently become drawn more into the political environment. Whilst politicians used to be ready to accept expert advice, ‘experts’ have become less credible and vaccination has been used by politicians to appeal to their supporters. Recent examples are Italy and the US.

Heidi Larson: I think it’s important that vaccine hesitancy is being addressed – the challenge is that it’s becoming so wide-spread that it’s more complicated to address. I think what’s happening right now, which is making the situation difficult, is that the world is not divided into people who are for vaccines and people who are against vaccines. There’s a much broader spectrum of views and I would say about 80% of individuals in most countries are getting themselves or their children vaccinated but they still have some questions, they still want some answers. Although these individuals have questions, but they are not against vaccines and shouldn’t be called ‘anti-vax’. Therefore, I think that we need to be careful with the language we use and about how to address those who have questions about vaccines, because I think that it is legitimate and responsible for young parents to be asking questions.

However, currently there’s a mix of genuine questions that are being shared and circulating on social media, and this is mixed with other information out there that is less genuine, that is more motivated to be divisive, sometimes for political reasons to destabilize. So, I think it’s important – and this comes back to why research is important – to understand there’s a spectrum of beliefs and to be sensitive to this realm of different views that largely believe in vaccines, but may have some questions.

This week marks World Immunization Week (24–30 April) – why do you think this is an important event?

Heidi Larson: I think that although there are a lot of world weeks and days to bring attention to different diseases or different health issues, they are important. Not that these causes should be forgotten about the rest of the year, but these weeks do bring an opportunity to highlight and to galvanize the public to think about things that we may take for granted on a day-to-day basis. Moreover, when you have a special week that’s saying ‘let’s have a fresh look at this’ I think it helps revive people’s engagement and involvement.

Bruce Gellin: We need World Immunization Week to remind everyone that vaccines are, and will always be, the best buy for global health. While this is a week that should raise the importance of addressing vaccine hesitancy around the world, it’s also a time to appreciate the progress made with immunization so far, like the fact that the world is excitingly close to polio eradication. That’s news that Dr. Albert Sabin would have been happy to hear.

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