Information Inoculation: Defending Against Medical Myths: The real reason polio is so dangerous | Dan Kwartler

0:00This is TED Health, a podcast from TED, and I'm your host, Dr. Shoshana Ungerleider. Today is the last episode in our vaccine miniseries. Over the past few episodes, we've looked at how trust is built, why it breaks down, and what we can do to navigate all the noise about vaccinations that's out there. This final episode is all about moving forward. What it really means to make informed decisions for ourselves, the people we love, and our communities. Because in a world full of uncertainty, understanding the science and the human stories behind it matters more than ever. Vaccines are among the most powerful tools in modern medicine, and also some of the most misunderstood.

0:44Consider polio, a disease that once paralyzed millions of people worldwide, now stands on the brink of global eradication, thanks to decades of scientific progress and public health efforts. But the fight isn't over yet. In this TED-Ed lesson, we hear about the surprising and complex challenges involved in eliminating a virus for good, and what it really takes to protect entire populations. Because preventing disease isn't just a personal decision, it's a collective responsibility. And at a time when vaccines are facing more scrutiny than ever, it's crucial to remember just how much they've already saved us from.

1:26Then stick around after the lesson for my interview with pediatric infectious disease physician, former chair of the U.S. Advisory Committee on Immunization Practices, and vaccine safety expert, Dr. Grace Lee. But before we dive in, a quick break to hear from our sponsors.

1:51And now, your TED-Ed lesson of the day. In 1952, polio was everywhere. For years, this virus killed or paralyzed roughly half a million people annually, leaving survivors reliant on crutches, wheelchairs, and respirators. Yet just 10 years later, paralytic polio cases in the U.S. dropped by 96%. Soon, similar trends spread worldwide, and it looked like we were on track to eradicate polio for good. But in the 21st century, the virus started striking back. So, what's the source of these recent spikes? And how can researchers fighting polio finally get rid of this deadly disease? To answer these questions, we first need to understand the true danger of polio.

2:46Most infected individuals only present mild flu symptoms or no symptoms at all, with paralysis occurring in less than 1 % of cases. Which is why the real danger of polio is how infectious it is. Historically, there have been three strains of poliovirus, all of which typically enter our mouths from airborne droplets or contact with infected fecal matter. This means polio runs rampant in communities with poor sanitation. And once infected, individuals remain contagious for three to six weeks, spreading a silent outbreak with few trackable symptoms. This is what made polio unstoppable until U.S. physician Jonas Salk found a solution in the early 1950s.

3:37He created an inactivated version of the virus that, when injected, prevented all three strains from causing paralysis. However, this inactivated poliovirus vaccine, or IPV, didn't stop poliovirus from living in our bodies and spreading to others. Fortunately, Polish-American microbiologist Albert Sabin was creating the oral polio vaccine, or OPV, at the same time. This even cheaper and easier-to-administer treatment contained weakened variants of each poliovirus strain, known as attenuated viruses. And once ingested, these prevented polio from settling in the body altogether. Over the next several decades, IPV and OPV eliminated polio in country after country.

4:33But near the turn of the century, this arms race between medical ingenuity and viral evolution took a turn. Scientists discovered variant strains of polio, each almost identical to one of the three existing strains. And their source was even more troubling. Up to this point, one of OPV's greatest advantages was that its attenuated viruses could spread just like wild polio, moving through the air and immunizing unvaccinated individuals. But researchers discovered that if these weakened viruses circulated for several weeks in under-vaccinated populations, they could mutate into new vaccine-derived strains.

5:21To be clear, this didn't mean the attenuated vaccine was inherently dangerous. OPV had already been used to stop wild poliovirus type 2 worldwide and eradicate all wild polio virus from the Americas, West Pacific, and countless other countries. The issue was ensuring populations met a certain vaccination threshold. Specifically, at least 80 % of every community needed to be vaccinated to prevent strains from mutating. So, in our current fight against polio, we've taken two approaches to this problem. First, vaccine developers have made even safer forms of OPV. Monovalent and bivalent OPVs, respectively, contain one or two types of attenuated poliovirus, reducing the number of strains that could possibly mutate.

6:18These vaccines helped eradicate wild poliovirus types 2 and 3. And today, they're tackling the last remnants of type 1 poliovirus in Pakistan and Afghanistan. Vaccine researchers also developed OPVs targeting vaccine-derived polio. Currently, most polio cases are caused by vaccine-derived poliovirus type 2 outbreaks in Africa and the Middle East. So researchers created a new vaccine specifically to tackle this strain with minimal risk of mutating. Second, medical workers on the front lines are using cutting-edge technology to ensure every population meets that 80 % threshold. Digital tools like geospatial imaging and analysis help them locate and immunize remote communities.

7:13Extensive monitoring systems ensure they don't miss a single child. And waste surveillance systems employed across the globe can alert us to potential outbreaks. Today, the fight against polio is at a critical moment. We're primed to eradicate wild polio virus in the near future. And with our new vaccines, eradicating vaccine-derived strains might not be much further off. But doctors still struggle to reach areas experiencing military conflict and civil unrest. And without keeping vaccination rates high, polio's silent outbreaks could easily surge. So it's essential that we keep up the pressure to finally finish what we started over 70 years ago.

8:11Today we're joined by Dr. Grace Lee. Dr. Lee is a prominent pediatric infectious disease physician here in the U.S. She's worked on vaccine safety surveillance projects side-by-side with health system colleagues across the country and in collaboration with public health agencies, including the CDC and FDA. More recently, she served as a member and then chair of the U.S. Advisory Committee on Immunization Practices from 2016 to 2023. As a physician, her experience allows her to bring a systems lens to the decisions that families face every day. Today, Dr. Lee and I are exploring what it really means to make informed decisions about vaccines, how we as individuals and parents can stay rooted in evidence, navigate the noise of misinformation, and still create space for thoughtful, compassionate dialogue.

9:02Dr. Grace Lee, welcome. Thank you for having me. So you led the Advisory Committee on Immunization Practices, which plays a huge role in shaping vaccine recommendations for the whole country. Can you take us behind the scenes a little bit? How do those decisions actually get made? And how do you balance the science with the real world risks and then the ripple effects for communities? Well, the Advisory Committee on Immunization Practices is a federal advisory committee that served the American people since 1964. So ACIP, as we call it, advises the director of the Centers for Disease Control and Prevention on how we use vaccines in the U.S.

9:44population to prevent the spread of infections, such as measles, influenza, whooping cough, and polio, and how to prevent serious complications from infections from happening. Part of the reason it's important to articulate that ACIP is a federal advisory committee is that the Federal Advisory Committee Act that was established in 1972 was put into place to ensure transparency, to promote public involvement, to prevent undue influence, and to ensure the advice of advisory committees is in the interest of the public. We have a charter, we announce meetings in advance that are open to the public and recommendations are made in public view.

10:24And I will say that although this has been in place for a long time, the pandemic certainly changed or substantially expanded the view of these meetings, which I think is a wonderful thing as we had to move to video conferencing. So all decisions have been made in public view and not behind the scenes. But there is a lot of work that happens between meetings within what are called work groups that are put together with a specific task that we call terms of reference to address a particular policy need. And these workgroups really do deep dives into the data to help us understand potential options for consideration by ACIP.

11:03And they are typically updating the committee and seek input along the way from the full committee. What people might not recognize is it's usually only several members of the full committee who sit on each of these workgroups. And that's intentional because we want to make sure all of the data is presented in front of the full committee who are making the final decisions and recommendations about vaccine use in the U.S. Ooh, that's such an important window. And I think that's where the bigger picture of how we learn and adapt over time really comes into play, or at least one example of that. I think some people think of science as something that's fixed.

11:41Like once we know something, that's it. But in reality, science is a process, not a destination. Can you help us understand how that plays out when it comes to vaccines? What I have come to realize from sitting on ACIP, and I sat on ACIP from 2016 to 2023. And thank you for your service, because that was a period of time where that was a very hard job. Thank you. Thank you. I think I might hold the record for the most number of meetings chaired by a prior ACIP chair, just in part because we had so many emergency meetings in the last few years. But in terms of change, I really appreciate that you describe science as a process and not a destination.

12:20I wish we always had the final and correct answer. But the one thing about science is you're always learning and you're always discovering. I take that as a really good sign that we're constantly incorporating new evidence that could lead to a difference in the recommendations. So after pneumococcal conjugate vaccine 7, so PCV7, came out around 2000, we saw dramatic declines in invasive and non-invasive pneumococcal infections in children. But actually what surprised everyone the most, perhaps, is the impact it had in the older adult population. And how does that illness present, though? Most commonly, it can present as ear infections or pneumonia and can result in some complicated pneumonias.

13:04Typically, an infectious disease doctor might get called if there's a bloodstream infection, for example, and it also was a cause of meningitis in children. So we saw dramatic declines in disease in kids who were being vaccinated, but the impact in the older adult population was quite impressive. We saw commensurate declines in invasive disease and hospitalizations due to pneumococcal infections in older adults. And those were of the serotypes covered by this vaccine. And essentially what we call herd immunity or another way to think about it is community immunity. Vaccines not only protect individuals, but really entire populations.

13:43This is what it's all about is not only do we protect those kids, but we protected their grandparents. So that's an amazing story of how vaccines can have a huge ripple effect on the entire population. So then thinking about where evidence might change the way we make decisions, when we saw that tremendous impact, ACIP at the time made a recommendation to offer the conjugate pneumococcal vaccine to older adults, hoping that it would augment or provide additional protection against something like a pneumococcal pneumonia, where older adults are often hospitalized with that. It did not have as much of an impact as we had hoped for at the time.

14:24And one of the uncertainties when they made that decision was not being sure whether the impact would help reduce further the risk of infection in that population, given the benefits that we already saw with childhood vaccination. So they actually, at the time, this committee proactively said, let's re-look at the data in four years and see if we made a difference. Four years later, we recognized that while we always want to offer protection to individuals who wish to seek that additional protection, we did not see a substantial benefit in the entire population in reducing the rate of pneumonia due to pneumococcal disease amongst the serotypes that were offered in that particular vaccine.

15:05So we decided to move from a universal recommendation to one of shared decision-making where people could access the vaccine and seek additional protection, but knowing that the benefit might not be as substantial as we had hoped. Fast forward, we now have pneumococcal vaccines, PCV21, that have actually been designed specifically for adult populations, where the types of pneumococcal infection it protects against are unique to the older adult population. We now have a recommendation for older adults where they can receive a pneumococcal vaccine that's tailored to the kinds of infections they're prone to.

15:45I believe that there's going to be a tremendous impact from that particular vaccine recommendation in this population because it wasn't covered by the childhood vaccine. That process for the public, I think, isn't always easy to sit with, though, especially when things shift or they evolve unexpectedly. I think for a lot of people, when they see guidance change, it can feel like, wait, were we wrong before? But again, that's just how science works, right? It evolves as we learn more. So how do we help people make peace with that uncertainty and maybe even see it as a sign that the system is working, not failing?

16:21I think similar to how you might approach a patient-physician relationship is the way I think about the committee. I'd rather have a physician who is honest, transparent, and humble in their decision-making, and always willing to take on new information to make the best decision for my care. And that's what I would hope for the committee too. The reasons that we change are because we want to make sure that we're incorporating the best and the latest data. And if we learn something new, we want to make sure we're continually revising our recommendations to ensure that we're providing our best foot forward for the U.S.

17:02population. I mean, I personally encourage people to feel comfortable being in a place where learning is seen as a good thing. It's better for us to acknowledge when we've learned something new that we can do it better and differently than it would be to just stay with the same recommendation just because we don't want to confuse people. I want to zoom in for a moment to the personal level and the kinds of decisions that families face every day. So let's talk about a scenario maybe a parent would face. They're sitting in their pediatrician's office trying to make the best decision for their child about vaccines.

17:37what kinds of questions do you wish that more parents felt empowered to ask? Not just yes or no, but the kind that really spark real dialogue and understanding. One of the ones that I really wish they would ask is what do we mean when we say vaccines are safe? Does that mean vaccines don't have any side effects? And the answer is no. Every approved product that comes to the U.S. has both benefits and side effects. And this is true of something as simple as an antibiotic such as penicillin or amoxicillin that you might take for a strep throat or for something like chemotherapy that someone might take to treat cancer.

18:16So when we're talking about safety, it's really about ensuring that safety is the balance of the benefits and the risks. We know that many cancer treatments, for example, have significant side effects, but we know that the benefits of treatment outweigh the risks associated with treatment. And in the strep throat example, you know, the benefits of treating strep throat is generally you get better faster, you reduce the risk of spread to others, and you can actually prevent future complications like rheumatic fever. But we know there are side effects, like some people will get a little skin rash or diarrhea, and that could happen.

18:52It's not very common, but that's what we're always taking into consideration when we're thinking about giving somebody a medical product. So when recommendations are made for vaccines, we're always considering the benefit-risk balance to ensure that we're improving the health of individuals and the populations and that the benefits of preventing infections and their complications outweigh the risks of vaccination. I think one of the things that I wish both patients and providers understood is how vaccine safety is monitored. I don't know if most people are aware that we have an incredibly robust process in place to ensure the safety of vaccines.

19:29And it starts from the very beginning. So as vaccines are being developed and tested in clinical trials to ensure they're both safe and effective. So for example, we have seen some of the largest vaccine trials with COVID-19 vaccines, recruiting approximately 40 ,000 patients for each trial. And these are placebo-controlled trials. And you might recall, this was back in the early 2000s, where there was a rotavirus vaccine trial that included over 70 ,000 infants that was specifically power to understand the safety of the newer rotavirus vaccines to ensure the benefits outweighed any risks. And FDA carefully reviews these trials before making decisions about licensure of vaccines.

20:13And that's part one. After a product is licensed, our public health agencies then conduct vaccine safety monitoring in the U.S. for any new vaccines that come on the market. And we call this post-market vaccine safety surveillance. So this is usually a combination of using something called VAERS or our Vaccine Adverse Events Reporting System, which is a system that anyone, a parent, a physician, anyone who sees individuals, they want to report any potential event that occurs following vaccination, whether or not it's related. And the reason we do that and make sure that it's open to everyone to report, and it doesn't matter whether you think it's related or not, is that it serves as an early warning system where the goal is really to detect rare signals early on.

21:00And it has worked really well in a few examples. And in addition, then we typically do prospective near real-time monitoring of vaccine safety that happens with systems such as the vaccine safety data link. So there is an intense effort to monitor the safety of vaccines before they get licensed and even after they're licensed for use. And the intent is that all of that information comes back into the committee to make sure that we're constantly weighing the dynamic benefit-risk balance of vaccines over time to ensure safety in the use of these vaccines for the population. Thank you so much for touching on some of the specifics on safety.

21:45That's incredibly important for people to know. And you touch on the value of dialogue in the doctor's office, and I think that really resonates. I've also heard from parents who say that they're not against vaccines. They just want to take it one step at a time. I think most parents, at least that I know, are trying to do what's best for their children. And that sometimes means weighing each vaccine like it's a separate decision, almost like ordering from a menu. And from your perspective as a pediatrician, how do you help families think through those choices in a way that feels both personal and then also, of course, grounded in evidence?

22:22So as a foundation, it's really important to know that ACIP only recommends vaccines where it's clear the benefits outweigh the risks. So the reasons for these recommendations are that either the burden of disease or how frequently the disease happens and or the severity of the infection, plus the availability of vaccines to prevent some of the infections and the consequences of these infections. I will just say that as a pediatric infectious disease physician who's still practicing, and I've been practicing for a while, I can say that I've personally seen kids hospitalized with nearly every single infection that's listed on our immunization schedule.

23:04So I've seen kids who've been hospitalized with rotavirus, pertussis, tetanus, haemophilus influenza type B, and this was just as the vaccine was taking effect. Pneumococcal infection, measles, varicella, meningococcal disease. I've seen HPV, influenza, and COVID. And some of these hospitalized children have gotten quite sick, needing ICU care, and some have passed away. Those diseases are real for me. They continue to be real for us as a community. And I think vaccines have had this transformative impact on childhood illness to the point where some of my younger colleagues have not seen some of these diseases, even things as it feels recent to me, but I guess it's not anymore, like chicken pox.

23:46It's not so common to see that anymore. And I recognize the value of these by understanding that I'm no longer seeing these kids coming into the hospital with serious infection. And I think that is something that I'm very grateful for. Well, so this leads to one of the common concerns that I've heard, the idea that spacing out vaccines might be safer. Maybe parents wondering if too many all at once might overwhelm their child's system. What do we actually know about that? And what are the trade-offs, if any at all, of deviating from that recommended schedule? So the current vaccination schedule has really been developed to try and offer protection to infants and children when they're both the most vulnerable, meaning they have severe complications from infection, and before they're at risk for exposure.

24:36And so many of our vaccines are often given in the first year of life. The challenge with spacing out vaccines is that it could leave young infants unprotected at a time when they're likely to become very sick with infection. In addition, there's the possibility that children and get pretty far behind if they're not able to come in regularly, which again, leaves them unprotected. Another way to think about it is balancing potential risks that people are concerned about with vaccination versus the risks of not vaccinating. And, you know, I wish I could predict with precision when someone will have a serious complication from an infection.

25:13That would be nice to do in the best of times, but it's getting even harder these days as our public health surveillance systems continue to go underfunded. To respond to the question about too many vaccines overwhelming the system, as vaccine technology has advanced, we're actually now giving fewer antigens to children compared to before. It's the parts of the bacteria or virus that get presented to your immune system to help it develop protection. So your immune system responds to different parts of the bacteria or virus to then create antibodies to offer protection. In the past, in the older days, we used to give just evacuated vaccines or killed vaccines where you typically killed the whole bacteria or virus.

25:58And we have realized over time that we've now gained the ability to provide more tailored protection with a smaller amount of antigen presented, such as subunit vaccines, recombinant vaccines, etc. And that allows us to focus on developing the immune response that's actually protective and minimize exposure to unnecessary antigen or parts of the bacteria or virus that doesn't induce that robust immune response. So we're really giving broader protection now for a greater number of diseases and with a smaller load on the immune system overall. Grace, polio is nearly eradicated. Measles was once declared eliminated in the U.S., but has made a resurgence of late.

26:42What do these patterns tell us about how fragile or resilient our public health protections really are? Well, we don't realize how dependent we are on public health infrastructure. It is always an area that is underinvested in, partly because it's easier to see when events happen than it is to see when we're not seeing events happen. So when an airplane crashes, we all know, we respond, and then we go back and we wonder, what could we have done differently? But when airplanes don't crash, we don't notice. We don't notice what's happening because we don't see all the systems that are in place to prevent that from happening.

27:23So I think that in general, as a society, we tend to take for granted all of the preventive work that's done to protect the public from serious events happening, whether it's polio outbreaks, measles resurgence. And we don't realize often until we see those events happening, how fragile the public health infrastructure can be. I just have the hugest respect for many of my public health colleagues who work tirelessly to do everything they can to keep our public safe, to keep our populations healthy, and often with very constrained resources. My hope is that we continue to invest in not only the infrastructure that's needed for prevention and response, but also the data infrastructure that we're going to need to ensure that we have those early warning systems in place to help protect us as events happen.

28:22I do worry that we undervalue prevention and we're more likely to invest in the response. Just to tie it back to the importance of vaccines, I think that's exactly what we're seeing, which is we often don't remember all of the things that used to happen because they don't happen anymore. But investing in prevention actually gains us so much health at a much lower cost than it is for us to respond when outbreaks happen. The flip side of that is the impact that one person or even one moment can actually have. We often think it takes a science degree or a huge platform to make a difference here. But in your experience, what are small but hopefully powerful ways that our TED Health listeners can show up for truth in their own circles?

29:11I have adapted the way I think over time. I used to think it was about making the big case or an argument for the importance of vaccines. But the older I get, that a lot of times it's much more about the conversation, as you mentioned. It's about listening intently, understanding what people value and understanding what their concerns are, and then trying to focus in on what's most important to them. And oftentimes when people are struggling with the decision, it can't necessarily be made in one fell swoop. So then I have to remind myself to be patient and to be willing to have a series of smaller conversations.

29:51For the most part, and for many individuals who have questions, they just want quick reassurance that they're about to do the right thing for their family members. And that's really all they need. But for others, it does take or may need a few additional conversations for people to feel comfortable. I'm going to go back to the fact that in general, our health systems are not incentivized for us to spend the time having those meaningful conversations. We're much more likely to focus on funding procedures or larger things that could be happening, as opposed to investing in the conversations that can help people really protect their health and advocate for what they are hoping to do together with their clinician.

30:34in the future, it would be a great goal for us to really incentivize the interaction and the time spent around these conversations that just really can and should happen in a busy clinical practice and or in a public health setting. I think it's going to be important for us to make sure not only are we enabling access across a broader population to make it easier for people to get vaccinated or to be able to have access to vaccines. But I think we're also going to have to think proactively about making spaces for those conversations with trusted messengers. And that can be providers. It can be community leaders.

31:12It can be within your Facebook group. It can be within those smaller communities that we have with each other to be able to move the conversation forward. If we imagine a future where, my goodness, I hope that trust in science and public health is restored, or at least looks vastly different, what do you think it will take to get there? And what role can individuals, not just institutions, play in making that future possible? I wish I had an easy answer for you. I will say I've started to reflect on how everything feels a bit like a pendulum that swings back and forth. And I remember when I was just a young physician several decades ago intersecting with vaccine recommendations that we attended as a medical profession to take a much more paternalistic approach to vaccines.

32:04But I think we now live in a culture where shared decision-making is the norm. Patients have far more access to information than they did three decades ago, which can be both good and bad. And online communities, I feel, have really empowered individuals to engage differently around their health. So as these cultural norms have changed, I think we as a profession need to continue to grow and adapt and learn how to engage in a different way. I actually also would like to advocate for an investment in education and training. I mean, communication is a science. We always do our best about learning the sort of specific facts and knowledge we need to gain in our training.

32:48But now more than ever, I wished back then that I had learned how to thoughtfully work on improving how I communicate with individuals and honestly with the public. There's so much I think I could learn now. If everything's a pendulum, my hope is we'll come back into balance. And to get back to the trust that we hope to have. I think it's first understanding where you have common ground, actively listening and asking those open-ended questions, making sure we're stating the facts and we're not shying away from the facts about the incredible benefits of vaccines and how it can protect you and your family members and your community, and then sharing experiences with your friends and colleagues and being open to continual learning.

33:33As you said, it is a process and an evolution. And my hope is that over time with stronger connections and greater trust, we'll be in a better place over the next five to 10 years. I hope so too. Dr. Grace Lee, thank you so much for having this conversation today. Thank you so much for inviting me.

34:01And that's it for today's episode. Thank you so much for listening. TED Health is a podcast from TED. And I'd love to hear your thoughts about this episode. Send me a message on Instagram at ShoshanaMD. This episode was produced by me, Shoshana Ungerleiter, and Jess Shane. Edited by Alejandra Salazar and fact-checked by Vanessa Garcia-Woodworth. Special thanks to Maria Lages, Farrah Degrunge, Daniela Balarezo, Constanza Gallardo, Tansika Sangmarniwang, and Roxanne Highlash. Thank you.