The Science of a Rumor

Contagious Conversations  /  Episode 23: The Science of a Rumor




Claire Stinson: Hello, and welcome to Contagious Conversations. I'm your host, Claire Stinson. Every episode, we'll hear from inspiring leaders and innovators who make the world healthier and safer for us all. Contagious Conversations is brought to you by the CDC Foundation, an independent nonprofit that builds partnerships to help the Centers for Disease Control and Prevention save and improve more lives.

Joining me today is Dr. Heidi Larson, professor of anthropology, risk and decision science and the founding director of the Vaccine Confidence Project at the London School of Hygiene & Tropical Medicine. Dr. Larson is also the author of a recent book titled Stuck: How Vaccine Rumors Start - and Why They Don't Go Away. In this episode, we discuss how the spread of misinformation on social media and through other channels can affect COVID-19 vaccine confidence and confidence in science, and how we can better understand misinformation around science and help stop the spread. Welcome, Professor Larson.

Heidi Larson: Good afternoon.

Claire Stinson: Thank you for being with us today. Heidi, you were referred to as a vaccine anthropologist by The New Yorker this year. That's a really cool title. Tell us what that means and maybe a little bit about how you started on this career path.

Heidi Larson: The title was given to me, and it was an interesting interpretation of what I do. I am an anthropologist. That's my primary training, and my investigation into what is driving vaccine confidence started about 20 years ago when I started to see some waning questions. But basically, the anthropology is trying to understand the cultural, religious, social, behavioral, belief-based reasons that people are questioning or hesitating about vaccines beyond the usual, the expected questions around safety.

Claire Stinson: Right. Absolutely, and what got you interested in this career?

Heidi Larson: Well, I was working at UNICEF at the time, and I was leading on the communications and strategy around new vaccines for the Global Immunization Program at UNICEF and also launching GAVI and chairing the Advocacy Task Force for the introduction of GAVI vaccines. It was during that time that I saw a growing number of episodes of questioning, refusing vaccines in different parts of the world, and by a very wide mix of everything, from some religious leaders to some government, to some individuals and communities, and I realized we kept trying to build confidence, but we weren't really spending time to understand why there were so many questions coming up, so it was really facing the front lines of questioning that prompted me to say, "I need to step out of the frontline, designing communication strategies and really start trying to understand better what's driving it so our communication and our engagement is more relevant to the concerns of people."

Claire Stinson: That's really interesting. It sounds like you've had quite a career, and it also sounds like you're perfectly positioned to work on the COVID-19 response, so let's talk a little bit about that. The spread of misinformation on social media and through other channels can affect COVID-19 vaccine confidence and confidence in science. Your research focuses on vaccine rumors, how they start and why some flourish and others don't. Talk to us more about that research and how it relates to COVID-19.

Heidi Larson: Well, sometimes I think there's too much focus just on the pieces of misinformation, and not on the fertile ground that lets it thrive. How vaccine rumors start and why they don't go away is because I see that there are some rumors that have gone on from the beginning of vaccines, and they come when the opportunity arises. Vaccines, one of the more common ones is about concerns about sterilization, that vaccines might sterilize them. We've seen it across a number of vaccines, but it reflects an underlying anxiety that some particularly marginalized populations have sometimes. But then, they disappear for a while, but they come up again when there's a period of anxiety or distrust in government, or it's a new vaccine and people don't know enough, so the research that we've been doing with the team I've built is really trying to understand, "What are those fertile ground factors that let these rumors thrive?," and in other settings, "Why are populations more resilient?," and the same rumor can start circulating, but gets no traction because there's a stronger confidence or resilience in some populations, but not in others.

Claire Stinson: That's really interesting. Let's talk a little more about the research and the team that you have built, that you just mentioned. In 2010, you founded the Vaccine Confidence Project, where analysts from a variety of specialties monitor news sites and social media in more than 100 languages, and then they strategize with local health groups about how to tackle the rumors that they find. Tell us more about that.

Heidi Larson: Well, we started the Vaccine Confidence Project, as you mentioned, in 2010, and the initial idea was to start to monitor online news media as a way to detect rumors when they would emerge early, before they would have a knock-on effect. I basically modeled it after what was starting to come up, which were a number of efforts to use online news media monitoring to detect disease outbreaks, and I thought, "Well, this is an interesting model for detecting vaccine rumors early," because I found myself in my UNICEF role, doing a lot of crisis management because people had brushed aside rumors as just being a rumor, and not really considering that actually, it could have some serious impact on disrupting immunization programs. We started in 2010 with online news media monitoring, and it was well before social media was as global as it is now. It was relatively recent, so we started with just online news media monitoring. Increasingly, we've expanded to social media monitoring because it became more global and we felt like we could get a better global picture. But we also developed what we call the Vaccine Confidence Index, because one thing you don't get with online news media or social media monitoring is representative samples from the population. And in the case of social media, you don't always even know where the voices are coming from.

The technology these days, you can get a much better sense of it than in the beginning, so we bring together different types of metric, nationally representative surveys, online news and social media monitoring. We're constantly reviewing the literature and studies that other people are doing, and trying to use as many different sources as we can to get the best picture of what's going on.

Claire Stinson: That's really fascinating, and also really unique. Are there a lot of other groups out there that do this kind of work?

Heidi Larson: Well, when we set it up, there were almost none. I mean, Julie Leask in Australia, was one person's research that I had come across, was already flagging the amount of negative misinformation that was found in Google searches, but that was in very early days, but there really wasn't a lot of attention. In fact, to the opposite, I was discouraged sometimes by focusing on this and being too negative. I didn't feel like I was being negative, I felt like I wanted to have programs succeed, so I thought it was important to understand where the weak spots were. Moving forward, there's been a growing appreciation and other scientists coming on board, but I haven't come across another group that's been fully committed to only really focusing on this for so long. There's a number of individual scientists who are doing some good work, and the field has grown tremendously in the meanwhile, and particularly in the context of COVID.

Claire Stinson: Oh, I'm sure. Thanks for sharing that. It sounds like all of this can really relate to COVID-19, such a unique and important mission of the Vaccine Confidence Project. Let's talk about COVID-19. What has your research shown about the main causes of rumors and misinformation around the COVID-19 vaccines, because we're seeing a lot of misinformation and rumors right now?

Heidi Larson: Yes. There's been a tremendous amount of rumoring and misinformation, but I would say partial information. It's not all misinformation, and I think that's been one of the challenges in COVID, because it's been such an evolving and dynamic situation where even the scientists only have pieces of information. That has made it even more challenging because rumors thrive in situations of uncertainty. The whole process of rumoring is a way that people try to make sense of things that don't make sense, that you can't really come to terms with, and I often say that rumors have a bad reputation because they're often assumed to be negative, but technically, a rumor is a piece of yet unverified information. And that's really the state of COVID, both in terms of a brand new virus that we're still coming to terms with understanding, and the new vaccines that have happened in remarkable speed.

Even before COVID, it was always the newer vaccines that spark a bit more anxiety, a bit more hesitancy. People want to wait and see to make sure there aren't side effects that weren't apparent in the beginning. So, it's been a kind of fertile ground for rumoring, and the partial information and sometimes misinformation has been a problem. One of the challenges that we've also seen is that because COVID and COVID vaccination is trying to reach everybody in the population, vaccine conversations have moved into groups that never talked about vaccines before. It wasn't on their radar, it wasn't something they were particularly interested in, and now, it's spread like wildfire into all kinds of both anti-groups and pro-groups, and that's really been beyond even my expectations.

I mean, I wrote an article for Nature in 2018. There was a lot of discussions and roundtables and articles on, "Are we ready for the next pandemic?," partly sparked by initially H1N1, and then Ebola, and then Zika. And anticipating that we were going to get another big one, like COVID, there were a lot of forms, and they asked me to write a commentary related to my work, and the title ended up being “The Biggest Pandemic Risk? Viral Misinformation.” That was the point of my commentary, but even then, I would've never imagined it being as explosive as it is today.

Claire Stinson: That was going to be my next question, so what has truly surprised you about your research?

Heidi Larson: Our research has just seen, as I mentioned, totally different groups, kind of getting involved with vaccine debates, discussions and also what's happening is that different types of groups, anti-government, anti-control, anxieties about technologies, anxieties about different issues have all kind of come together, which has created a much bigger, a locus of alternative thinking, and also the amount of conspiracy that has come up. We've had conspiracies forever in humankind, but the way it's infiltrated society in, much more mainstream than I would've expected.

Claire Stinson: That's interesting. Thanks for sharing that. Heidi, you have authored a book titled Stuck: How Vaccine Rumors Start - and Why They Don't Go Away. In the book, you say that we should look at rumors as an ecosystem. You also argue that listening to rumors and the stories behind them is crucial for rebuilding trust. Tell us more about this book.

Heidi Larson: Well, Stuck actually was just going to press just as COVID was announced and the last chapter is on publics and pandemics, so I urged Oxford University Press if I could even add a paragraph at the end to acknowledge that this was going to press as COVID was announced.

Claire Stinson: Right.

Heidi Larson: They came back to me and said, "Listen, write a 1,700-word prologue to frame the book in the context of COVID," which I did. We are going to be running another edition of it, and I will be writing a new prologue reflecting on the last year and a half, but it was really interesting to go through the book that I had written totally before COVID to inform the prologue in terms of how it's relevant. It was fascinating to me because it was so relevant, or is so relevant, but again, this was at the beginning of COVID, and I look forward to reflecting more specifically about it, but the book itself looks back at a lot of learnings over the last decade in our work at the Vaccine Confidence Project. I do look at it in terms of emotions, the contagion of emotions, issues around dignity, issues about respect and rumors, the nature of rumors themselves. I say it's an ecosystem because rumoring, as I mentioned before, is a way humans try to manage and make sense of uncertainty, of risk, of things they don't understand, and that it's really important that we give space for that.

One of my biggest concerns right now is the extreme polarization where there's no room for this kind of middle ground of exploring and trying to make sense of things because it's also very high-risk to be deleting pieces of what might be deemed as misinformation when in fact, it's just not yet confirmed. In the context of a brand new virus, brand new vaccines, we have to be extremely careful with what we delete because one of them might actually be a signal of something, either some reaction to a vaccine or some new behavior about the virus, that we have to be very careful to delete things before we can confirm that they're not true.

So, it's not an easy space, for instance, when governments tell Facebook or Google or Instagram or whoever to delete the misinformation. It's not that straightforward. I talk about that in the book a bit. I also talk about how WHO, the World Health Organization, in their basement has a whole archive, a rumor archive from the smallpox eradication initiative.

Listening for rumors was hugely important, especially in the last stages of eradication when people needed to listen for any possible signal of a case of smallpox, because if there was even one case in the world, it would never be eradicated. There's an important scientific function for rumors, and also for early signals of disease outbreaks. That's why I talk about it having to learn to live with rumors, but manage them in ways that when information is clearly confirmed, but people still hang on to them when they're not true, that's when we need to contain them and manage them.

Claire Stinson: That's a good point, and that's really interesting that you wrote the book, and it was going to publish right as COVID was coming on the map. So, Heidi, we’re talking about misinformation here, I like how you explained that sometimes we need to understand that it's just partial information. How can we better understand misinformation around science and help stop the spread?

Heidi Larson: Science is constantly questioning itself. I mean, that's the whole nature of science, and that's kind of hard for publics to digest sometimes because if you read a scientific paper, it always leaves some open piece that more could happen, we can learn more, which from a public perspective sounds ambiguous and sounds not totally confident, but from a scientific perspective, it leaves an openness to discovering more. One of the things I say in the book is enlightenment, and the age of enlightenment looked at science as freethinking against religious dogma. Well, what publics are feeling these days is that science is the new dogma. Science said, "So you should do." I think we have a bigger issue on the relationship between science and publics.

Claire Stinson: No, that's a really good point. That's a really good point. Heidi, I enjoyed reading the article in the New Yorker earlier this year about your career, and you're quoted as saying that, "A successful vaccination effort requires the public to trust the scientists who create the vaccine, the companies that manufacture it, the healthcare workers who inject it and the governments that oversee the process.” And you refer to this as a trust chain. How can we strengthen this trust chain right now with the COVID-19 vaccine?

Heidi Larson: Well, we can't strengthen the trust without each of those pieces of the chain building trustworthiness. I think we point a lot of fingers at the public and talk about building trust, but I think all of us who have any role in the whole vaccine field need to look in the mirror and say, "What can we, in my piece of this bigger effort, do better? How can we be clear, or how can we make our piece of the work more engaging and trustworthy for the public?" And that's a big challenge. The whole relationship between risk and trust is an important one to consider too, because when people have more trust, they're much more willing to put up with a little risk if they see a benefit, if they see a greater good. If they don't trust, they don't even want to put up with a little risk.

Claire Stinson: Absolutely. A really, really important point, and trust is key in all of this. Where have we seen successes in recent times as it relates to communications around vaccinations?

Heidi Larson: The successes I've seen in trust-building and engagement, particularly in the context of COVID, has been hyper-local. The more local, the more familiar, the more trust-building. I think that some of the big lessons we've learned and really need to remember in terms of preparedness for the future, we made a lot of assumptions about leadership in our preparedness plans. We assume that leaders around the world, in the face of a highly-fatal epidemic would line up, that different people and different ways would line up, and it just hasn't played out that way in different countries for different reasons, but where the strength has shown its face and where the successes I've seen are really in the local communities where ... One of my really favorite efforts is the Black Coalition Against COVID and how the Black doctors in different communities really worked closely with and built confidence, and the drop in hesitancy was really impressive. And also, I mean, some of the stories that I'm sure you've all heard about, engaging barbers and hairdressers, farmers, restaurant owners. Like in the Bangladeshi community in London, I was really impressed there. People that you would've never expected to be involved in any kind of vaccine communication effort or engagement effort, and that's one of the wonders of COVID. I think that the immunization community and immunizations programs in general are very, I think sometimes too focused, and not getting enough partners outside of the immunization program. I think this has been a huge opportunity for unexpected and valuable partners in immunization program to get engaged the way they have. But I think local resilience, community engagement, familiarity, particularly when we're living in such a hyper-uncertain time, people are craving for familiar things that they know, that they understand, that they trust, and the more we can leverage on those familiar areas, the more we can build confidence.

Claire Stinson: That's an important point, and it does certainly seem like communities are key to this trust chain that we've been talking about.

We'll be right back with Professor Heidi Larson. If you would like to learn more about Professor Larson's Vaccine Confidence Project, please visit

Now, back to our conversation with Professor Heidi Larson.

Heidi, what do you see as the biggest and best opportunities to stop the spread of misinformation and restore broad trust in vaccines?

Heidi Larson: I think we need to look at why some of the reasons that people are gobbling up some of the misinformation. To me, what I look at is, "What aren't we doing well enough? Why aren't we giving a better story from the informed story?" I try to think of it being a challenge to the public health community to say, "There's something going on with the way the misinformation is portrayed that is in a much more engaging way than the way we're putting it out in the public health community." One, we need to do a better job of engaging publics so they're less tempted, as it were, by the misinformation because they're not getting or finding or compelled by the more factual information.

I think the other thing we need to look at on the misinformation side is rather than just focusing on asking social media companies and tech companies to get rid of or to clean up the misinformation, which is really not only challenging, but not always possible because a lot of what's out there is not straightforward misinformation, it's ambiguous, it's seeding doubt, it's asking questions, and that you can't ethically delete. But one thing that I think would make a huge difference is to slow down the algorithms that are spreading the information in general. Slow it down. Give us time to catch up, to do better, to surround it with different ways. It's frankly a bigger ask than clipping out the harmful misinformation because it has business implications, but I think that would really help, is just slow it down.

Claire Stinson: That's interesting perspective. I know in the New Yorker article, you also said that we really need to listen to the stories behind these rumors because there may be some truth to some of them, and I know another expert we've interviewed in this podcast has mentioned the need for deep listening.

Heidi Larson: Absolutely. A lot of the surveys that we see are, "What are your feelings? What are your ..." Well, it's not even really about feelings, it's, "Are you willing to take a COVID vaccine?" and then finding out a lot of background, demographics and whatever, but to take it past the initial question. I remember in our polio work when I was with UNICEF, for instance, in India, in some of the more difficult polio vaccine-resistant communities, at a superficial level, if you asked the first like, "Why don't you want to take that vaccine?," and it was often, they would say, "Oh, we're worried it sterilizes us," which was one of the circulating rumors.

When we sat down and listened a bit more and said, "Well, what else is bothering you, or what else is going on here?," and opened up the conversation, we learned that actually, what they really didn't like was men vaccinating their children, and particularly, men coming from other cities, and then going away again. They wanted local vaccinators, women vaccinators, that if there was something wrong, they knew where to find them to help them, and once that infrastructure thing changed, once there was a switch to more local female vaccinators, the uptake started to increase, and the rumors started to fade. If there hadn't been that longer conversation and revisiting and coming back and saying, "How are you today?" "What else is going on?"—maybe they're too shy to talk about what's really bothering them.

Claire Stinson: Right. That's really, really important perspective to remember in all of this. Heidi, you're in a unique position to provide this advice, but what advice would you share for public health workers listening to this podcast right now that are dealing with the spread of misinformation about COVID-19 vaccines?

Heidi Larson: Well, I think the important thing right now is that we have a world with people who are tired, anxious, don't want to really hear more about a COVID vaccine. They need some compassion. I think that from a public health perspective, and frankly, just in our daily life, we need to ask people, "How are they doing? How are you coping? How are you doing?"

It's not just about deleting their misinformation or correcting their misinformation, or asking why they're not getting their vaccine, but just the gesture of asking how they are, because just that gesture makes people feel like you care about more than just that vaccine. "Oh, no. Here comes X. They're just going to ask me about getting vaccinated again." Talk about things that they might care about.

Ask them how they're feeling, what they think are the most important things to get to the other side of COVID, and then maybe bring in the conversation about vaccines, or if they start talking about misinformation, you can come around to that, but I think we need to frame our conversations in a bit of compassion.

Claire Stinson: That's really important advice. So important to share right now. Thank you for that. Here's a big question to end today, what are your thoughts about the future of public health?

Heidi Larson: I think we need an overhaul. There's a lot we've learned in COVID, some things that we already started to know about how we needed to engage with publics maybe a bit differently. There's been this, and I talk about this in Stuck, a growing divide between publics and public health, and we need to really reframe how we're approaching it to be more in touch with publics, and it's been really hard with the rate of change with all the digital technology has been going at a speed and pace much faster than the public health community has evolved, and this isn't everywhere to be fair. There are some places that have been able to get more engaged with the types of technology and communication that publics are much more nimble with than the public health community, but I do think we need to catch up a bit with that. I think we're realizing the limits, the boundaries of communication technologies.

When a lot of this new technologies, and particularly, social media came up, it was a kind of honeymoon period, a euphoria. You see the optimism. You see the possibilities for kind of a friendly conversations, and we're realizing the limits of that, and that's where the regulations start coming in, and that's where the restrictions start coming in. We've got on the one hand some things to do with the new technologies and managing that, but at the same time, I think we, in the public health community, need to be a little less scared to go into the social media space, which I feel like there's some anxiety about going there. It's emotions. It's not all fact. It's a harder space to control, as it were. I wouldn't say at all, that's the fault of public health. It's the reality of living in a fast-changing era of technology that needs a nimbleness and evolution and investment in ways that kind of caught us all off guard, but I think COVID can help give us a bit of a roadmap of where the weak spots are and where the opportunities are.

Claire Stinson: You have such interesting and unique perspective on all of this. This has been a fascinating discussion. Thank you so much for being a part of Contagious Conversations.

Heidi Larson: Thanks so much, and I love the framing of Contagious Conversations.

Claire Stinson: Thanks for listening to Contagious Conversations, produced by the CDC Foundation, and available wherever you get your podcasts. Be sure to visit for show notes. And if you like what you just heard, please pass it along to your colleagues and friends, rate the show, leave a review and tell others. It helps us get the word out. Thanks again for tuning in, and join us next time for another episode of Contagious Conversations.