Commemorating a milestone: The 70th anniversary of the polio vaccine announcement

Commemorating a milestone: 
The 70th anniversary of the polio vaccine announcement 

0:00:38 Audio Clip: The attention of the world centered on the University of Michigan on April 12th, 1955 when the results were made public. The report given by Dr. Thomas Francis confirmed that one of the greatest medical achievements of all time had been accomplished.

“If the results from the observed study areas are employed, the vaccine could be considered to have been 60 to 80% effective against Paralytic Poliomyelitis.”

0:01:06 Host: Hello and welcome to Population Healthy, a podcast from the University of Michigan's School of Public Health. Join us as we dig into important health topics, stuff that affects the health of all of us at a population level, from the microscopic to the macroeconomic, the social to the environmental, from cities to neighborhoods, states to countries and around the world. We are recording in front of a live audience as we commemorate a momentous anniversary.

0:01:33 Host: Today we turn our attention back 70 years to April 12th, 1955. It was a day that truly changed the world, and it all emanated down the street at Rackham Auditorium right here on the University of Michigan campus. With nine words, the work led by Thomas Francis Jr. And Jonas Salk raced around the globe. The vaccine works. It is safe, potent, and effective. We're talking about Salk's polio vaccine, which was confirmed, safe, potent, and effective by Francis' field trial, the largest ever undertaken. Relief and joy spread worldwide. The devastating effects of polio could be relegated to history. On this milestone anniversary, 70 years since the announcement of a polio vaccine, we are pleased to bring together two experts in conversation to discuss how the vaccine was developed, its impact and insights for modern times. Dr. Matthew Boulton is the Senior Associate Dean for Global Public Health and Professor of Epidemiology here at the University of Michigan School of Public Health. He's an expert in childhood vaccination and vaccine preventable diseases. And Dr. Natasha Bagdasarian is the Chief Medical Executive for the state of Michigan, as well as an adjunct Professor of Epidemiology at Michigan Public Health. She's an expert in internal medicine and infectious diseases. And now please help me welcome Doctors Matthew Boulton and Natasha Bagdasarian.

0:02:50 Matthew Boulton: Thank you for that wonderful introduction and I want to welcome you all to this edition of Population Healthy. I want to especially acknowledge our visitors in the in-person audience from the Rotary Club who've done so much to further the efforts to eradicate polio from the world. I'm Matthew Boulton, Senior Associate Dean for Global Health here at the School of Public Health and Professor of Epidemiology. And I'm joined by my good friend and colleague Dr. Natasha Bagdasarian, Chief Medical Executive from the State Health Department. Good morning and welcome back Natasha.

0:03:27 Natasha Bagdasarian: Thanks for having me here today, Matt.

0:03:30 MB: Yeah, I say welcome back. A few months ago we did a podcast together on immunization programs in the state of Michigan. So I'm guessing we didn't mess up too badly 'cause they've asked us back again. Alternatively they couldn't get anybody else to do it, so they asked us to come back. So I'll take it either way. So before we jump into polio I'd like you to talk just a little bit about your position at the State Health Department as the Chief Medical Executive, the chief doctor at the State Health Department, especially as your work in impacting and communicating immunization policy and programs in the state of Michigan.

0:04:06 NB: Well, Matt, I'm happy to talk about my position. It is a position that you know well because Matt actually held this position before me many years ago and was one of my faculty when I was here at the School of Public Health. So everything I know comes from Matt. So my position at the state of Michigan is mostly advisory. So I advise the governor and I advise the Department of Health and Human Services on any medical or public health issues. And one of the topics that has really been front of mind for me since I took this position in 2021 are vaccines and vaccines hesitancy. One of the things we're seeing, especially right now, is a lot of misinformation and distrust, not just about vaccines, but on a lot of public health topics and just distrust in science and folks not really feeling connected to government entities.

0:05:01 NB: We're also seeing a decline of trust in healthcare and clinicians, which is very worrisome. But one of the things that we talked about last time, Matt, is we've seen a decline in vaccination rates statewide. We've seen this in Michigan in some parts of the state more than in others. We're seeing this really around the country, and it's leading to a resurgence of infectious diseases. We've seen a resurgence of pertussis. So last year was one of the worst years we've had for pertussis in a long time. This year is likely to be even worse. And when we look at what's happening across the US with measles, this is likely going to be the worst year for measles that we've seen in decades, very sad when we have the tools to prevent such things from happening. So I'm really glad that we're here to talk specifically about polio because number one, it's timely and it's an anniversary and something we should celebrate, but also because this is a time when we have to really highlight some of the progress we've made and make sure we don't take steps backwards.

0:06:05 MB: Yeah. Thank you Natasha. The announcement of the polio vaccine as safe and effective from the University of Michigan on April 12th, 1955, was a seminal event of the 85-year history of the school public health and the 200-year history of the University of Michigan. So what I'd like to do is have you set the stage for us and talk about polio in the first half of the 20th Century pre-vaccine. What did it look like and what were the concerns around polio?

0:06:46 NB: So in preparation for today's event I was not around in the first half of the 20th century when polio was causing destruction and fear. So I watched a lot of archival footage and really I've already used this word once today, but the word that comes to mind is fear. We were really seeing an improvement in sanitation and public health across the board in the early 1900s. And what was really concerning to people is that as sanitation was improving, somehow, they were seeing more and more cases of polio. 1916, there was a terrible outbreak in New York City that raised a lot of concerns and fears. They were screening kids who were moving across state lines from New York. Again, just a lot of concern because people really didn't understand the dynamics of transmission.

0:07:47 NB: There were all kinds of techniques that people were using to try to keep their kids safe. I was reading about kids being sent away to camps over the summer because there were more outbreaks during the warmer months. So kids were being sent out into the countryside to avoid populated areas during the summertime. There were big campaigns where they were spraying pesticides on buildings and in urban areas, even though there was no data to suggest that this was a disease being transmitted by flies. So it was fear and people were really looking for answers. And then of course, things really came to a head in the 1950s. And 1952 was one of the worst years the United States has seen with polio outbreaks. There were almost 60,000 cases of polio and 3000 cases of paralytic polio in 1952.

0:08:43 NB: And again, people just wanted to keep their kids safe especially because this was a disease that was impacting typically kids under the age of five. And at that time I was also watching how impactful and how much the March of Dimes movement gained in terms of traction. It was really a sense of people coming together. They were seeing kids develop the horrible consequences of polio. They were seeing kids in iron lungs, and people were sending in those dimes. It was a real sense of what can we do to address this problem together. And I know you're going to talk about the announcement a little bit later, but it was very moving to watch some of that archival footage and see mothers weeping at the announcement, and church bells ringing. It was a real sense that something had changed for humanity.

0:09:42 MB: Yeah. And it had, and it had. To recap just a little bit of the history of the vaccine development here at the University of Michigan, the university received a charter to start a new school of public health in 1941, which marks the first year of the School of Public Health, even though we had given out degrees related to public health prior to that. Our first dean of School of Public Health was Henry Vaughan, who at the time, was Commissioner of Health for the City of Detroit. One of the very first things that Dean Vaughan did is he reached out to a nationally known virologist at Mount Sinai Hospital in New York City by the name of Dr. Thomas Francis Jr. And he offered him, he said, why don't you come to the School of Public Health and become the first chair of epidemiology? And Dr. Francis agreed to do that.

0:10:38 MB: Dr. Francis arrives, one of the very first things he does is he reaches out to an outstanding young physician scientist he's worked with at Mount Sinai Hospital by the name of Dr. Jonas Salk. And he said, why don't you come to the University of Michigan and work with me on vaccine development? And Jonas Salk says yes. So he arrives at the school in 1942 and the two of them proceed to work together. And Dr. Francis deserves tremendous credit for really teaching vaccinology to Jonas Salk, how to develop a vaccine. And Dr. Francis, in fact later on, goes to develop the very first influenza vaccine in the world. Jonas Salk finishes the fellowship, and I don't think this is generally well known, but he actually comes onto the faculty at the University of Michigan as an assistant professor of epidemiology. It's relatively short-lived 'cause he's recruited away by the University of Pittsburgh and with the support of March of Dime dollars, sets up a lab and a large research group and begins working on a polio vaccine.

0:11:49 MB: A few years later, he feels like he's developed a viable and effective vaccine, but it needs to be tested in the real world. What'd he do? He turns back to his mentor at University of Michigan, Dr. Francis, and asks, will you conduct a real world field trial of this vaccine? Which Dr. Francis says yes to, still the chair of epidemiology here. 1.8 million children are enrolled in that study, which to this day is still the largest or one of the largest field trials that have ever been conducted. It started in April of 1954, and the intent was for it to go 2 to 3 years so they could fully test the vaccine. One year later, it was readily apparent to Dr. Francis that this was a fully effective and safe vaccine, and they called off the trial early, which led to the announcement on April 12th, 1955 in a national press conference that the vaccine was safe and effective.

0:12:55 MB: So that then leads us to the beginning of the post vaccine era. And I wonder, Natasha, if you can talk about what the effect of that vaccine is. I will say too, let me add that it's very personal for me because I have had Dr. Francis' desk in my office for the last 20 years. And in fact, when I first got the desk, I had been to the state health department and I came here and I got the moving guys, 'cause we had built the new part of the building and we had a Francis room and that was torn down. And so the desk was there, and I asked the moving guys, I said, Hey, would you move this into my office? So I had a little tiny 10 by 10 office, and the desk is huge. They put it in my office. And so in order to get in my office, I had to climb over the top of the desk to get to the seat in order to sit at the Francis desk. Now my hope was that I would be inspired to great scientific discoveries like Dr. Francis. And after 20 years, I'm still waiting for that to happen. So Natasha, if you could take us then into the post vaccine era, what happened? Especially with cases of polio?

0:14:08 NB: Well, I just want to add, Matt, we had really hoped you would do a demonstration today of how you climb over that desk every day. But this vaccine was really a game changer and cases of polio plummeted. So you mentioned, of course, in 1955, we had the Salk vaccine announced, and by 1961 we had the Sabin vaccine. Polio was declared eradicated from the US by 1979 and eradicated from the Western hemisphere in 1994. So a lot of progress occurred here, but we can't forget the progress that has occurred globally. So in 1988, the Global Polio Eradication Initiative was launched, and the results of that have really been impressive. So we've averted 30 million cases of paralysis since 1960, since that vaccine was available. So basically a 99% reduction in cases since 1988.

0:15:17 NB: We only have two countries where polio is still endemic, Pakistan and Afghanistan. And I can't really emphasize how hard people working on the ground have really toiled to make sure that vaccine was given in every village, in every remote locality, even when there was a lot of distrust to people coming into communities from outside, even when there are concerns about people bearing vaccines, having ulterior motives. So despite these hardships, we've had workers go to the most remote parts of those countries to make sure vaccine is given. Which really brings us, I think, Matt, to what's happening in today's climate and how things are changing for us globally. Do you want to say a few words about that first?

0:16:13 MB: Yeah, I mean, I think we definitely want to segue that into our conversation. I want to back up a little bit, 'cause you mentioned the Sabin vaccine, which was the live oral vaccine. So it was administered on a sugar cube, unlike the Salk vaccine, which is an inactivated injected vaccine. So we get the Salk vaccine in 1955 and then in the early '60s, the Sabin vaccine comes on board as a live vaccine. There's a large clinical trial that is run here in the US and so we end up largely switching globally and domestically to the Sabin oral vaccine because it provides a bit better immunity in certain circumstances. But then we switched back to the inactivated, the Salk vaccine in the mid '90s. What was that all about? Why the switch?

0:17:06 NB: So there came a time, with every vaccine we're looking at benefit-versus-risk ratio. And with every vaccine there comes a time when you have to reevaluate benefit versus risk. And so there was a time in the 1990s where we were not seeing wild type polio circulating, but we were seeing cases of vaccine associated paralysis. And so as a result in 1999, the US switched from the IPV sorry, we switched to the IPV.

0:17:39 MB: Right.

0:17:41 NB: Although in much of the world it was still more feasible to provide the oral polio vaccine because of ease of delivery. You don't need a needle. You're using a sugar cube. You can go to more remote parts of the world where access to needles and syringes is more limited. You can utilize folks to give out vaccines who may not have that same level of training. And so in much of the world, OPV was still being used.

0:18:13 MB: Yeah. In fact, I received, I grew up out west and I received the Sabin vaccine on a sugar cube, as did my many brothers and sisters. And I recall that several of us tried to get back in line a second time so we could get a second sugar cube, which really didn't work out. They, we...

0:18:33 NB: That sounds like something you would do, Matt.

0:18:36 MB: Yes. Yeah. So yeah, we are in a really challenging time. So we have ongoing transmission in just a couple countries, and so we've made tremendous progress, but right now is a very challenging time. We've seen the US Agency for International Development has sustained some pretty large cuts, which is true of a number of our global health programs. What do you, if you had to look ahead, what do you think the impact, if any, of those cuts generally of global health program might be on vaccine preventable diseases, especially in low and middle income countries generally, but polio specifically?

0:19:18 NB: I think we have to look at this larger picture. You mentioned USAID, but of course it's not just USAID. We've seen massive cuts to the CDC, not only cuts in funding, but in personnel. There are entire divisions at the CDC where no one is really there to pick up the phone in the same way they were just a few months ago. We've seen data systems go down. We've also seen the US pull out of WHO. In a former life I worked for WHO writing COVID guidance. And I have to say that at the best of times, it's an agency that's severely underfunded and the United States is one of the biggest, or actually the biggest donor of the WHO. So we're doing away with the work being done by USAID, we're doing away with the knowledge and human resources at the CDC, at the same time we're pulling out of WHO.

0:20:17 NB: And there's also a concern for the direction some of our scientific agencies are being steered these days. There is a push to reinvestigate vaccines that have proven track records for many decades. And that worries me because again, I think we're creating more misinformation, more perception that there's a risk when in actuality we know the risks. They've been well, well studied for decades. And so all of those things trouble me. All of those things lead me to believe that we're taking a step back when it comes to vaccines across the board. But especially with polio, when we're so close to global eradication, we could be so close to global eradication. I think taking a step back now could be very damaging.

0:21:22 MB: So taking that a bit further, do you see any real threat to polio returning to the United States?

0:21:31 NB: Well we are still at risk for imported cases, so long as there is polio circulating anywhere. And with all infectious diseases, if we get a traveler associated case, it really depends on where that traveler returns. If that traveler returns to a community that has robust levels of vaccination, we tend to be safe. If that traveler returns to an area where there are very low levels of vaccination, then it puts us all at greater risk. And I think for some time now, folks in my generation who are parents of younger children, they have had the privilege of opting out of some of these vaccines and they've had the privilege of doing this because these diseases no longer seem like an imminent threat to them. But things could change. And I think so long as there are diseases like polio anywhere, we are all at risk.

0:22:38 MB: Thank you, Natasha. Looking ahead so we've got some challenges in front of us. Our ultimate goal is of course, the complete worldwide eradication of polio just as we achieved with smallpox. Do you think that'll happen at some point in the foreseeable future? And I'm going to put you on the spot, when do you think that might happen?

0:23:07 NB: Matt, I think it could happen. For a number of reasons; because we have effective vaccines, because there is no animal reservoir, because we know the routes of transmission, it could happen. But all of our tools are useless if they're not utilized. And so I think utilization and investment in continued public health efforts around the globe are what we need. 

0:24:00 MB: One thing I wanted to ask you about was that one of the challenges with polio globally right now is we are seeing a polio-derived from the vaccine in circulation. So we have wild type polio in countries like Afghanistan and Pakistan, but then we also have vaccine-derived polio that's in circulation. How much does that complicate the eradication picture?

0:24:29 NB: I think it complicates things a fair bit. It complicates our surveillance. When we're doing, for example, wastewater surveillance, I think it leads to consternation among the public if we are picking up on vaccine-derived strains, which has happened in wastewater surveillance in the recent past. So I think it's a complicated picture, and until we can move to the non-oral polio vaccine everywhere, I think this will continue to confound the picture.

0:25:02 MB: Yeah. When do you think that Yeah, so the question has arisen because of course, when you take the live oral polio vaccine, one of the disadvantages is induces good immunity, but you also shed live virus, and so it can result in transmission. And that's what we've been seeing is that this vaccine-derived polio has been in circulation. Why don't we just make the move to IPV now globally?

0:25:31 NB: I think that's something that folks are really talking about, the Infectious Disease Society of America wrote a strongly worded letter about this not too long ago. It is complicated, Matt, because the infrastructure constraints still remain. If you are going out to remote areas where it's very difficult to administer an injectable vaccine, it's easier to administer oral vaccine. Also, part of the benefits of using oral polio vaccine is that it does confer some protection to contacts. But then on the downside there is the potential risk of further transmission and potential vaccine-derived complications. So it's a complicated decision. I think it's really going to depend on what is happening on the ground, on how many cases we're seeing in some of these remote parts of Pakistan and Afghanistan. The decision will have to be made by people who are working there and who are living there and who have better optics on what's happening. But again, we need funding, we need infrastructure, we need surveillance. We need all of those things in place for a global public health response to something that is now a global issue.

0:26:48 MB: In the current state of affairs in the US, so we have a Director of Health and Human Services, Robert Kennedy Jr. He's described himself, and I'm using his own words, he's described himself as a vaccine skeptic. Do you think that's likely to have any impact on polio vaccination levels? And I wonder if you could comment, what do polio vaccination levels look like in the US right now, and do you think there's any possibility that spilling over into the generally high levels of polio vaccination that we've achieved in this country?

0:27:22 NB: I think vaccine skepticism, it doesn't just impact polio vaccine, it impacts all of our childhood vaccines right now. What we're seeing in Michigan specifically, is we've seen a decline in childhood immunization rates since the beginning of the pandemic. We saw rates decline from about 75% for kids between the ages of 19 and 35 months, that includes the polio vaccine series. So it dropped from 75% to about 70%. Now, to me, that doesn't sound like anything terrible or frightening, but it's the heterogeneity that we're seeing. It's the difference in small communities that is really most troubling to me. So when we look at the nation as a whole, or if we look at a single state as a whole, we're not seeing declines that are shocking or particularly frightening. It's when we go down to the community level, when we look at counties where vaccination rates have just plummeted, when we look at school buildings that have vaccination rates of 20% or 30%. That's what's troubling because a single case, a single traveler derived case of any of these diseases, so polio, measles, mumps, any of these diseases could result in a massive outbreak.

0:28:42 NB: And so looking at things at a community level and also understanding then what are the barriers? What are people's concerns? Why are people saying no to vaccines on such a large scale in these micro communities, what is the misinformation that's circulating? I think that becomes really important to discuss.

0:29:03 MB: Yeah, and that leads to my follow on question: What can we do in terms of health communications? What's the successful strategy for countering misinformation and what seems to be spreading vaccine hesitancy? I mean, right now we're in the midst of one of the largest measles outbreaks that this country has seen in the last 30 or 40 years. I think I read recently that there's now 22 states involved, started in Texas, I believe, 22 states involved, including Michigan. So what's the successful strategy to counter misinformation and vaccine hesitancy?

0:29:45 NB: I'll talk about two solutions, but just really quickly, Matt, your point made me think of an analogy that I discussed with a reporter. We were talking about measles last week, and I was describing how some of these very low vaccination communities are so vulnerable. And he said, oh, it's like a wildfire. And you've got burning embers that are just floating around in the air, and it really depends on where the ember lands. And if it lands on a pile of kindling, you end up with another wildfire. And I said, yes, that's exactly what it is. We're dealing with these embers and we just don't know where they're going to land. In terms of how do we combat this, I think there's a short term solution and a long term.

0:30:26 NB: Short term, we're doing some pretty cool things here in the state of Michigan. We've got something that we just started called the Michigan Communications Initiative, where we're working with a national group that looks at what misinformation and disinformation on specific topics are circulating in your area. One of those topics is vaccines. So they're looking at what is the misinformation? Where are people getting incorrect information? They're creating targeted messaging that we can send out to address that misinformation. And then, because people don't necessarily want to hear from the Department of Health and Human Services, they may not even want to hear from their local health department, we're sending those messages to a huge network of local organizations that include churches and youth groups, and YMCAs, all kinds of different partners, because perhaps people will feel more comfortable receiving that information from their local group that they trust as we see trust being eroded in some of the larger institutions. So that's short term. I think whatever we can do to combat misinformation, we will keep doing.

0:31:45 NB: Long term, I think there's a bigger problem. I think we're dealing with an erosion of trust in science, an erosion of trust in government, in academic institutions, and how do we rebuild that? And that, I think, is going to be the more sustainable option. It's also the harder option, and I think it's going to take us decades to build back some of that trust. And how do we lay the foundation? I think first of all, we need robust research into what are the reasons for some of this erosion of trust and how do we work on better messaging? What went wrong during COVID? What went wrong in our communication of uncertainty and nuance when we put out some of that COVID guidance? So we need research. We need to repair some of the erosion of trust in some of our most trusted messengers. I'm hearing from our healthcare partners that their healthcare institutions no longer feel that the public trusts them the same way. And if people aren't trusting doctors and nurses in the same way, that really worries me. So I think there's a longer term, how do we build back what we've been losing over decades, but then what took a big hit during COVID?

0:33:09 MB: Well, thank you. I think we're about out of time. It was mentioned earlier that you are an alum of the School of Public Health. I think you went through the program in the early 2000s. And I know our audience is very interested to know who was your favorite professor as you went through the program?

0:33:32 NB: It was most clearly Matt Boulton.

0:33:37 MB: Oh, that's such a surprise. Well, and I've had thousands, guess who my favorite student was in a thousand, right here, Dr. Natasha Bagdasarian.

0:33:49 NB: Matt does not remember me from grad school. Don't believe a word he's saying.

0:33:54 MB: Well, you, no, no. You were in the top 75% of my favorite students. But you've ended up in the top 1% in terms of your contributions to public health. And I think we're all tremendously appreciative that you joined us today. And also a big thank you from all of us for all you do to impact the health and improve the health of the citizens of Michigan. It's been a real pleasure having you back to join us again, Natasha, for this Population Healthy podcast.

0:34:26 NB: Thanks for having me on. Thanks for this great discussion, and thank you so much for the audience. You all have been fantastic.

0:34:34 Host: Let's hear it for Dr. Matt Boulton and Dr. Natasha Bagdasarian one more time. What a fantastic conversation. And again, thank you to you, our audience. We're grateful for your participation in today's event. This has been Population Healthy, presented by the University of Michigan School of Public Health, recorded live here at the School of Public Health. Population Healthy is produced by Andrea LaFerle, Brian Lillie, Crissy Zamarron, and Michael Kasiborski. Visit our website populationhealthy.com for more resources on the topics discussed in this episode, and to find more episodes. If you enjoyed the show, and we're sure you did, remember to subscribe, rate and review wherever you listen to podcasts. Be sure to follow us on social media and consider sharing this episode with friends. We hope you can join us for our next episode, where we'll dig in further to public health topics that affect all of us at a population level. Thank you.