Making Sense of Measles Misinformation

Chris Dall: Hello and welcome to the Osterholm update, a podcast about infectious diseases and public health featuring Dr. Michael Osterholm. Dr. Osterholm is an internationally recognized medical detective and director of the center for Infectious Disease Research and Policy, or CIDRAP, at the University of Minnesota. In this podcast, Dr. Osterholm draws on over 50 years of experience in infectious disease epidemiology to provide straight talk on the latest infectious disease outbreaks, counter misinformation and disinformation about vaccines, and distill the complex and ever evolving public health threats facing our world. I'm Chris Dall, reporter for CIDRAP news, and I'm your host for these conversations. Welcome back everyone to another episode of the Osterholm update podcast on August 25th. Pennsylvania Governor Josh Shapiro, along with officials from the Pennsylvania Department of Health, announced two measles associated deaths in unvaccinated residents of Lancaster County. The first measles deaths in Pennsylvania in 35 years. Citing privacy concerns, state officials did not release any other information about the deaths. Governor Shapiro made it clear that he linked the two deaths in part to misinformation about the MMR vaccine. Some of it coming from the federal government. Folks are spreading skepticism about things like the MMR vaccine without any evidence to back up their claims, he said at a press conference. That scares parents, and it plays a role in why so many people now are getting measles for the first time in decades.

Chris Dall: But in the ensuing days, questions arose about the role that measles played in the deaths of one of the victims, a newborn who tested positive for measles and whose mother had been infected at the time of birth. The Lancaster County coroner says he doesn't believe the death was related to measles. Health Secretary Robert F. Kennedy Jr. suggested Shapiro had rushed to politicize the deaths, which he suggested may have been fabricated. The coroner has said the second death, also an infant, was caused by measles, but the CDC says it wants to further investigate the deaths before it labels them measles associated. We'll discuss these two deaths and the controversy surrounding them on the September 10th episode of the Osterholm update, episode number 217. We'll also highlight the takeaways from the independent review of COVID flu and RSV vaccines by CIDRAP. Vaccine Integrity Project and the American Medical Association. Answer an ID query about the timing of COVID and flu shots. Provide an update on the Ebola outbreak in the Democratic Republic of Congo and assess the state of vector borne diseases in the United States. We'll also bring you the latest installment of This Week in Public Health history. But first, as always, we will begin with Dr. Osterholm opening comments and dedication.

Dr. Michael Osterholm: Thanks, Chris, and welcome back to the podcast family. It's good to be with you again. And as I say, each and every podcast, if you're joining us for the first time, I hope we're able to provide you with the kind of information you're looking for. Each and every time that I start these podcasts, I get this feeling kind of a warm feeling of just knowing you're out there and that we're here. And even though we are potentially many, many miles apart in our physical presence, we surely can feel you in so many ways. And so thank you for being part of this experience. Today, I'm going to reflect on really two different dedications because I think they're both very, very timely. And you'll see, ironically, how they are actually linked in many ways. Last Friday, September 4th, mark the 25th anniversary of us opening the doors to a small and unheard of place in the University of Minnesota called the center for Infectious Disease Research and Policy. At that time, the university took a flier on us, basically a small group of us coming forward, saying it was time to pull together a center that dealt with both policy and research in a way that talks about the integration of that information and what that meant. And I can't say any stronger terms how fortunate we have been to be at the University of Minnesota, given the fact that the support has never wavered over the 25 years. It's incredible how 25 years have come and gone during that time. We have grown beyond my wildest dreams of what we could ever have been.

Dr. Michael Osterholm: Thinking back to 2001 as an old man, reflecting more often each day on the gifts of life I've been given, now more than ever, I understand Margaret Mead's famous quote: "Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it's the only thing that ever has." 25 years later, it's clear to me that CIDRAP has made a difference. And why is that? Because of the people. Not just the people who work at CIDRAP, although they are obviously very key. But the people who depend on CIDRAP for the kind of information that can shape how you respond in your personal and professional lives. After 25 years and a little bit of wisdom, I know now more than ever that CIDRAP is not a place. It's the people. It's an incredible staff that make it possible for CIDRAP to do what they do. And it's you, the audience, the people who count on us and take that information we provide in such a way as to hopefully make the world a better place. Last Friday, on that 25th anniversary, I sent a note to all CIDRAP staff suggesting that they take a step back and think about somewhat of this historic moment, a moment where both our professional and personal contributions to the CIDRAP mission were gifts that we share every day. We have staff who have been on board since the very first day 25 years ago, including Kris Moore, Marty Swain, myself or others who joined us in the past year.

Dr. Michael Osterholm: You are now part of the CIDRAP family. You too have helped make contributions to public health in a way that we should all be proud. Now, I know I won't be around for the 50th anniversary of CIDRAP, but some of the staff very well could be, and lots of the audience members will be. What a gift it's been to be part of that first 25 years. And thank you to the people, the staff, the incredible staff at CIDRAP and you, the audience. And I just have to acknowledge one more thing about the CIDRAP staff. Many of you'd be surprised to know, no, we don't have three floors in a building. We don't have a heliport on the top of the building. Some people suggest We are 39 very committed people who care a great deal about the public's health. We are very, very fortunate to have this amazing team. And I just want to acknowledge something very, very important in my life. You know, when I run, the way I run, sometimes you can think I would run into a wall and I would if I didn't have the support of administrative assistants who, frankly, run my life for me in many ways. And I want to acknowledge today, Judy, Mandy, who in 2001 came with us to the university on that flier of we're going to start a new center, stayed with us for seven years, retiring in 2008. And then Laurel O'Neal came in 2008 and stayed until 2024 before she retired in northern Minnesota 16 years.

Dr. Michael Osterholm: And now Sarah Morris, a name that's familiar to many of you who is now at CIDRAP and has been for the past two years. I just want to personally thank them for literally being air traffic control in my life, and for helping all of us keep on task. At CIDRAP. Now, one of the messages that I also want to share with you is that CIDRAP was heavily, heavily influenced by the events of nine over 11. And in fact, remember, we actually opened our door exactly one week before nine over 11. And it so happened that the previous Friday, I actually was in Washington, D.C. at a meeting on terrorism and came back over the weekend. So when the events of nine over 11 unfolded, it was indeed a very personal experience. I want to just acknowledge today and dedicate this podcast also to those who died at nine over 11, 2,977 people died that day between the World Trade Center towers, the Pentagon and the Shanksville, Pennsylvania site. What a tragedy. But I also want to acknowledge today that we're seeing a very painful residual of that nine over 11 event. So many people spent the next months trying to bring some resilience to that area of New York City, working countless hours in those piles and knowing that there had been 3 to 400 tons of pulverized asbestos that had come down with those buildings. Today, we're seeing so many illnesses related to taking in the toxic World Trade Center tower dust to you and your families.

Dr. Michael Osterholm: You continue to suffer the impact of that nine over 11 event. We must never forget nine over 11, but we also have to remember it for not only the very painful part of what happened, but the heroic nature of so many people and how as a nation, we came together. So today, I'm here to celebrate the incredible team at CIDRAP, and I'm here to also celebrate the dedicated people who did so much to respond to the nine over 11 crisis and set the tone for what we as a nation over the months to years ahead, were able to experience. Now with that, let me move to the sunny side of life today in Minneapolis on September 10th, sun rises at 6:46 am, sunset at 7:33 pm. That's a whopping 12 hours, 47 minutes, and seven seconds of sunlight. Yep. It's true. We're losing sunlight at about three minutes and four seconds a day, soon to be close to that three minutes and six seconds of sunlight lost, which will be our maximum period of loss coming in late September. Now, I'm happy to report that our dear colleagues in Auckland, New Zealand, at the Occidental Belgian Beer House on Vulcan Lane today, your sun rises at 6:29 am, your sun sets at 6:07 pm, 11 hours and 38 minutes and three seconds. We still got your beat, but you're gaining sunlight at two minutes and 17 seconds a day, and it's just a couple of weeks we will cross over, for which then it becomes your gift to see the light of the world.

Chris Dall: Mike, I laid out the controversy over the two measles associated deaths in Pennsylvania. In my introduction, the story unfortunately turned into a political spat between Secretary Kennedy and Governor Shapiro. But from what is publicly known about the dead infants, one of whom, according to reporting by The Atlantic, was the child of an Amish couple. Do you think state health officials were correct to label this death measles associated?

Dr. Michael Osterholm: Well, let me just start out, Chris, by saying how tragic this is and how deeply we all feel about the loss of life in this newborn child. And let me also add that what has unfolded in terms of the debate back and forth between the Department of Health and Human Services and specifically Secretary Kennedy and the governor of Pennsylvania is unfortunate. Why? Because in fact, that's not how you adjudicate a situation like this. And at the same time, it only creates more confusion in the public's mind. Is this a government cover up? Are these really being fabricated? What does this all mean? So let me just take a step back and say, first of all, let me clarify how information is made reportable to the CDC for infectious diseases. Remember, I've shared this multiple times with you in the past. The federal government has no authority over what a state actually decides to do surveillance for and report that information onto. Cdc in public health is a state's rights issue, and the feds do not have authority over that. So in the past, the system we've set up over many, many decades for reportable diseases is one where the states, through the Council of State and Territorial epidemiologists, decide which diseases will be reportable, and they decide how those reports actually will come in for which types of cases. And what I mean by that is, in some cases, we do surveillance for the actual case occurrence and report that.

Dr. Michael Osterholm: And in other instances we don't do population based surveillance, but rather count the deaths relative to what's happening with that disease. Best example I can give you is both pediatric influenza and pediatric COVID cases. We don't count the numbers there as a reportable number, but we do count deaths. And again, those numbers come together as a result of what the Council of State and Territorial Epidemiologists recommends. So today, what we find ourselves in is a very unusual situation in that we have not set up a system for counting measles deaths like this, because in fact, we just hadn't had measles deaths. And when you go back and look at the last 20 years, there was no need to develop a fatal case of pediatric measles. Now we are finding ourselves well, we're going to need to have that, it looks like down the road because this is going to likely happen more and more. What we've witnessed the last 20 years is not going to be our future. If you're a clinician who's never seen a measles case in your life, if you're on the front lines, I promise you you're going to see a measles case in the near future. Even in this situation, that very kind of situation played out. We have a family practice physician who was named coroner for this county, who had never seen a measles case before in his career.

Dr. Michael Osterholm: And so now he was making a judgment about whether or not this one particular case actually died from measles. And I wish that he had done more to reach out to experts in the area of infectious diseases. And we have linked in the footnotes of the podcast today, a commentary by Dr. Paul Offit on the death and how the coroner handled it. And so one of the other areas we want to emphasize is that as a nation, we're going to have to get a lot better at understanding not only how to handle patients clinically, but also what does that mean in terms of counting deaths? And so there was nothing questionable that Pennsylvania did over many, many, many decades. They reported a case of measles that in fact was reportable. This child absolutely had measles virus identified in their lungs. And the question was, did they die from that? Well, that's where public health really needs to play the key role in the assessment of what contributed to the death. And we have just been through that over the last six years with COVID, how many times do we get into debates about did that person die from COVID or do they have COVID when they died from some other cause? This is no different here. What we needed to have was a discussion of this case among experts who know what they're talking about, about what might be a cause of death when you actually are also infected with measles virus.

Dr. Michael Osterholm: So all I can say at this point is that I believe what data we have seen would suggest that both the cases as the one, as you noted, Chris, in fact, already now has been confirmed as associated with measles. But I think both of these children, in fact, died in part because of their measles infection. And what we need to do is keep this out of the political arena, keep this where it's all about the experts. It's all about calling balls and strikes. It's not about trying to cause some kind of a political debate or discussion, which is just so unfortunate. So the state, I think, did the right thing. I can understand why in some instances they do not report the more information about the case because of the issue of confidentiality. As state epidemiologist in Minnesota for all those years, there were a number of times we ran into situations where we had an obligation to protect somebody's identity and did not provide enough information to the media to satisfy their need to know what had happened. But at the same time, that conflict of protecting the patient's confidentiality. So I don't see any suggestion here at all of anything nefarious. I think right now we all in public health know we're into some real headwinds in the future with measles, and we're going to have to get a lot better at understanding how to identify it, how to treat it, and how to deal with unfortunate situations like a death and a child.

Dr. Michael Osterholm: I also want to add a footnote to this discussion to say that we've also posted the link to an article that appeared in The Atlantic entitled "The Measles Stricken Mother Who Lost Her Newborn Son," by Tom Bartlett. This article really provides a wonderful overview of understanding what happened with this particular case in the Amish community in the Lancaster, Pennsylvania area. It is a heart wrenching story to read, but it's also pointing out there's so much we can do. This family was not opposed to vaccines. They had just not sought medical care that ever put them into a position to have their children vaccinated. I think one of the real messages we have to get across here is, is that we also need to make certain people such as this understand what's happening in their community, what the risks are for their family to become infected, and unfortunately, even potentially get seriously ill and die. And so if there's any message that comes out of all of this is that we all have to take measles very seriously today. And even in situations where we think an individual may not agree to be vaccinated with truthful and thoughtful information, I really believe that this is one of those families that would have vaccinated their children.

Chris Dall: The CDC, in its August 30th update, said it was not listing the two deaths because, quote, "available information does not establish whether measles caused or contributed to the deaths or whether the individuals died from other causes while infected with measles." And to date, that position has not changed, even though, as you noted, Mike, the Lancaster County coroner has said that the second infant death was caused by measles. This is unprecedented for the CDC to question another state's determination of death from measles or any other infectious disease. So, Mike, what does this tell you about newly confirmed CDC Director Erica Schwartz?

Dr. Michael Osterholm: I think this entire event, again, which I just noted, is quite tragic in terms of public health practice illustrates the fact that anything and everything that is politically motivated will likely show up on this whole entire public health surveillance activity for measles. Now, I've just laid out for you an answer in the previous question that supports how the process is handled in this country for adjudicating. Does someone have disease X, disease, Y, whatever. And from my perspective, what really is unfortunate is the fact that newly confirmed CDC Director Erica Schwartz basically took 50 to 60 years of public health practice of how diseases are counted, how that counting takes place, and made this become part of the political fabric of this debate. I think she disqualifies herself from this point forward. Being a CDC director that you can trust will put public health first, despite having said that at her hearing. And to better understand what happened in terms of this decision of how to call this case, I refer you to another article that we've linked in the footnotes by Dr. Jake Scott, an op ed that appeared on the CIDRAP site. I think after you read that, you'll get a much better handle on what actually transpired with this situation. Unfortunately, I fear that every time a death from measles occurs in this country, there will be an automatic challenge, the cause of death phenomena, and that is only going to create more and more confusion in the public. So we need to do what we can to maintain the business of public health as we've done it for decades. I know that will be a challenge. CDC is not likely to be a part of that process, but I think we as states surely can hold up the standards of disease surveillance that we have done for all these decades and say, this is the truth, this is what we will count, and this is how we're going to talk about it.

Chris Dall: Mike. Pennsylvania currently has the largest outbreak in the country right now, but other states are also seeing measles cases climb. So what is the national picture look like right now. And do you expect things to get worse now that school is back in session throughout the country?

Speaker 3: Well, Chris, before I answer this question, I want to reflect back on something I said in a previous episode of the podcast. I gave you a sense of what could be the future, hoping that it would never actually materialize. I actually addressed the issue of what had happened in Canada last year, our neighbor to the north. I hope they stay our neighbors. It's a crazy time. But you may recall that in 2025, they reported over 5400 cases of measles, and it was largely around these pockets of vulnerability that I talked about. Situations where schools, because of social, cultural norms, whatever, only 40% of the people are vaccinated. It's exactly what we're seeing right now in so many locations in this country, Lancaster County in Pennsylvania, being an example of that. Well, if you think through this situation, I believe that we are beginning to emerge in a very similar track as Canada went through last year. Now think about this. Canada has 40 million people. The United States has almost 350 million people. If, in fact, we were to see the very same rate of measles, not a higher rate, the same rate of measles in the United States that Canada saw last year, that would be almost 50,000 cases of measles that we could expect in the next year. Think about that. That's incredible. And yet right now we're unfortunately moving towards numbers like that. I hope that's wrong. I hope that that's not what happened. But Hope's not a very good strategy today when it comes to public health. And so all I would want to emphasize is you asked this question about what's likely to happen in the future.

Dr. Michael Osterholm: Understand, this scenario I just shared with you is not something just made up. It is just happened to our neighbors, to the north, who are as much like we are as a country in terms of our undervaccination. So they do serve as that canary in the mine. We'll see. But let me go back to the question you asked. Pennsylvania certainly is pulling all the measles headlines right now. But there's unfortunately plenty of measles to go around. In our last episode, we covered how cases are increasing in Pennsylvania and Ohio and how kindergarten MMR vaccination rates have declined, especially in states like Idaho. I'll start with a brief update on Pennsylvania, where the things aren't slowing down. Cases continue to grow. And importantly, this is not just a Lancaster County story. The virus is spread into more than 25 counties in Pennsylvania, including the western part of the state. Earlier this year, the biggest media stories were in Utah and South Carolina. Although the growth there has cooled down, those two states still account for roughly half of all the 2026 cases so far. And I'm not ready to rule out the possibility that pockets of unvaccinated people in those states could reignite things again. One state that we haven't reported on recently is Wisconsin. Our very dear neighbors to us here in Minnesota as of early September, there are now more than 100 cases, and they're rising very quickly. Cases have nearly doubled in a single week. Measles cases are concentrated in three rural counties in the southwest corner of the state Grant, Iowa and Lafayette. It's a good reminder that a handful of cases can turn into triple digits very quickly once they reach an under-vaccinated community.

Dr. Michael Osterholm: Responding to your question about the impact of school reopenings, I think it's likely to accelerate spread, but with some nuance. Measles risk tracks local vaccination coverage more than the calendar itself. A well vaccinated school is still a lower risk environment compared to a camp, daycare, or faith community, with lower coverage in communities that are well under the 95%, quote unquote, herd immunity threshold. There's a risk year round kids coming together for school is certainly one way for this virus to make its way into the population, but that's not the only one. Let me remind you that in historic times of measles, talking about 20, 30 years ago, measles cases tended to be on a similar cycle to that of influenza, with a maybe slightly later peak in late winter and early spring. But there clearly was a seasonality to that. We're not there yet. So now combine the ongoing transmission in these communities with what could be a season that would enhance transmission coming before us. So the big question looming over us is whether the US will, in fact, continue to see this growth in cases. And what will it do in terms of our official measles elimination status? Let me just say that we have a decision forthcoming from the WHO in the next several months. But I am certain that measles elimination will no longer be a part of our program. Rather, we will be just trying to basically minimize the impact of severe outbreaks. I feel certain measles elimination status is now gone.

Chris Dall: So let's turn now to the COVID flu and RSV vaccine evidence reviews published last week by CIDRAP Vaccine Integrity Project and the American Medical Association. Mike, there's a lot we could discuss, but what are the most important things our listeners and the public at large need to know about these reports?

Speaker 3: Well, let me be really honest with this very special audience. I'm so darn excited to talk about this one. It actually, of all the things I've covered for many, many, many podcasts, this one gets my juices flowing more than any. Chris. I don't want to bury the lead here. So I will start off by saying that our partners at the National Medical Specialty Societies issued their updated recommendations for immunization against COVID, influenza and RSV last week. This guidance and leadership in the current times without a function ACIP is absolutely crucial to protecting Americans from severe outcomes caused by these respiratory viruses. And yep, this is the part that makes me very proud and goes back to that very dedication that I started this podcast with. The Vaccine Integrity Project's role in this massive undertaking was to conduct a systematic review of the published literature on the three pathogens, focusing on data that has come out since we conducted the reviews last year. Now sit tight for this one, because it may be hard for you to believe we had to review 19,158 articles that were published in that time addressing these three vaccines, and we had to do it in a very specific, protocol driven way, etc. this was not just a casual review. This was a labor of love, and one that I'm sure I cannot adequately convey. The commitment that the Vaccine Integrity Project staff put into this very issue. I'm on to highlight a few of the notable findings from these publications for our listeners. One vaccinated in the pregnant parent provides considerable protection against severe outcomes in the infant for all three respiratory pathogens. This is in contrast to the statements from the Department of Health and Human Services that these vaccines are not necessary in pregnant people. Number two, the newly approved mRNA flu vaccine was 27% more effective against symptomatic disease compared to the standard dose vaccine among adults 50 and older.

Dr. Michael Osterholm: This surely helps me make a decision about which vaccine I want. I want that new mRNA vaccine. Three COVID vaccinations among adults 65 and older reduce the risk of hospitalization by 53% last season, and the risk of emergency department visits among young children was reduced by a whopping 76%. Four infant immunization with RSV monoclonal antibody reduced the Reduce the risk of hospitalization by up to 93%. Amazing. 93%. And lastly, there were no new safety concerns identified by analyzing the most recently published data across all three pathogens. A very brief summary of an incredibly comprehensive review. The entire body of evidence was delivered to the following medical societies who wrote their annual recommendations for their own subpopulation, the American Academy of Pediatrics, covering children. The American College of Obstetricians and Gynecologists covering pregnant people. The American Academy of Family Physicians covering adults and healthcare personnel. And the Infectious Diseases Society of America, covering those who are immunocompromised. The American Medical Association then collated all of these recommendations into one centralized website. Spread the facts.org. We will again also link that in our show notes on that website. Healthcare professionals and patients can access each set of recommendations, along with resources like infographics, FAQs, and more. Each component of this effort was organized with the goal of delivering coordinated evidence and recommendations as a unified announcement for the public. The science can be complex, but the bottom line is straightforward. The latest evidence continues to support immunization as one of our most important tools for preventing severe disease from COVID, flu and RSV, and people deserve access to recommendations that are informed by that evidence. Thank you to our partners at AMA and the medical Subspecialties. We did it.

Chris Dall: So while we're on the topic of viral respiratory illnesses, Mike, what does the COVID flu RSV picture look like right now around the country?

Dr. Michael Osterholm: Well, not much has changed since our last episode. We're still seeing increasing COVID-19 activity. No signs of the start of the RSV season and very minimal but expected increases in flu activity. The percentage of outpatient visits for influenza like illness or ILI, has increased slightly, but is lower than at this point during the past six flu seasons. That's since 2020. Again, this increase is expected and is nothing to be alarmed about yet. Before we dive into the COVID-19 numbers, I want to add a disclaimer about the increases we're seeing. The scale we're talking about is so much smaller than any other point throughout the pandemic that it's tough to tell if we're seeing a peak or we're seeing what I at one point called a flurry of activity for some specific context on this difference in scale, we may be able to say that over the past month, the hospitalization rate has doubled, but we're talking about going from a rate of 0.3 hospitalizations per 100,000 people to 2.7 hospitalizations per 100,000 people. Rates that are still lower than previous years. For reference, during the Omicron surge, hospitalization rates doubled in two weeks from 16.2 per 100,000 to approximately 36 per 100,000. In January of 2022. So all we're talking about increasing COVID activity at the moment, going from 1 to 2 is much less significant than going from 10 to 20. Please keep this in mind as we look at the data here.

Dr. Michael Osterholm: The national COVID-19 wastewater concentrations remains very low, but it is slightly increasing. Concentrations have continued to increase in every region, with the West now considered moderate and the South considered low. Texas is the only state with wastewater concentrations considered very high. Four states Arizona, Hawaii, Mississippi and Montana are considered high. Eight states have moderate concentrations. Seven states in the District of Columbia are low and the remaining states are considered very low. Since our last episode, emergency department visits for COVID 19 have increased in every age group, remaining highest in children under one year, followed by 1 to 4 year olds. COVID 19 related hospitalizations have increased slightly, with age specific rates fluctuating week to week, but remaining highest in children under one year. Taken all together, especially in the West, I think the sustained increases in viral activity suggest we are in fact seeing a somewhat of a wave. And this isn't just a coincidence. Again, I want to emphasize what do we mean by a wave? Surely some increase. But this wave is much, much smaller than any that we experienced during the pandemic. There is a lot that we still don't know about this virus. We don't know if this is a small wave that will peak and cool off, or if it will be followed by a bigger wave. Of course, as always, we'll continue to monitor viral activity and keep you up to date with everything you need to know.

Chris Dall: So that brings us to our ID query, which this week comes to us from David. He writes, Dr. Osterholm is quite emphatic to wait until flu season is underway to get a flu vaccine, but just as emphatic to get a COVID vaccine as soon as the vaccines are released. Can you explain the reason why the timing is different?

Dr. Michael Osterholm: Thanks for this question, David. It is really an important one, and hopefully I can clear it up so that you can explain this to your friends and family too. It really boils down to the fact that we have two respiratory viruses that behave differently with different seasonal trends. On one hand, we have COVID, which, as we talked about in our last episode, seems to come in 2 to 3 waves each year. But with each wave getting smaller and smaller, these waves also tend to be somewhat variable in their timing. On the other hand, we have flu, which has a fairly regular seasonal pattern with activity that starts to tick up in the fall in mid to late October, and then another bump in the spring around February or March. Now we have a similar issue with both viruses. The protection from our vaccine wanes lasting months, so timing our vaccines to provide us the most protection while viral activity is at the highest is very key. As I have noted before, we know that from influenza vaccine. Once you're vaccinated, you lose anywhere from 2 to 8% of that protection each month following your vaccination. So if you were to get your vaccination 5 or 6 months before the actual peak in activity occurs, your vaccine will be providing a lot less protection that had than had you gotten the vaccine just a month before that peak.

Dr. Michael Osterholm: So that's why I always emphasize about the flu. We know when it's starting to come. We have time to tell you. Now is the time to get your shot. Well, with COVID, that's not the case. I mean, just with my answer I gave you just a moment ago about what's happening with COVID. You can see how it's kind of iffy. Is it going to get worse? What will it look like if it gets worse? What areas of the country will see the biggest impact? And that's why we say get your COVID vaccine now. So you're covered against all eventuality like flu. We also do see waning immunity with COVID vaccines. But at this point, it doesn't look to be necessarily as significant as we see with influenza. So I continue to stick with the recommendation. Get your flu shot. When we first see flu activity start to pick up. And we'll keep you posted on that. Get your COVID shot now because it very well could be sitting on the edge of a cliff ready to jump to cause us real harm. And so from that standpoint, you're basically using the vaccines to the very best you can to deal with the variability in two different viruses, but ones that teach us both that waning immunity is important.

Chris Dall: Now to the ongoing Ebola outbreak in the Democratic Republic of Congo. DRC officials recently launched a campaign to vaccinate frontline workers with the Ervebo vaccine, which targets a different strain of Ebola but may offer some protection against the Bundibugyo virus. Mike, do you think there's a chance this strategy could, at the very least, slow an outbreak that is otherwise out of control?

Dr. Michael Osterholm: Well, Chris, let me just start off by saying, in the absence of a licensed, targeted vaccine against Bundibugyo virus, it's the best tool we have. The situation, as you said, is out of control. Let me provide some context. At the end of last week, the WHO announced that they need at least 5000 more workers in the DRC to help control the Ebola outbreak, and that the outbreak is spreading rapidly and geographically. In addition, another 1,600 beds are estimated to be needed. Now, mind you, the numbers here outbreak totals of what we know about include over 6,686 confirmed Ebola cases and 3,226 deaths. This is truly on its way to becoming the worst Ebola outbreak we've ever seen in all of continental Africa. Now, late last month, the first doses of the vaccine were administered in the DRC. As you noted, the vaccine targets the Zaire Ebola strain, not the Bundibugyo virus, which is causing this outbreak. But data from some animal studies and in vitro studies in humans indicates that it might provide some cross-protection, even if it doesn't prevent infection. Could it make your case milder? Health and other frontline workers are being prioritized for the 50,000 doses of the vaccine, with another 20,000 doses reserved for a clinical trial. There are being vaccinated under compassionate Use, which allows vaccines and other medical products to be used in outbreaks when they haven't been approved for the specific disease being targeted. DRC health officials said they will conduct follow up to evaluate the effects of the vaccine. In the meantime, they said, some healthcare workers who received the vaccine during a 2018 Ebola outbreak and have been infected in this outbreak aren't getting as sick as those who weren't vaccinated at that time.

Dr. Michael Osterholm: So that's hopeful. But it is anecdotal. A number of research projects designed to assess whether vaccines already or previously licensed against Zaire Ebola virus, including Ervebo, are underway. CEPI, an organization that works to speed the development of vaccines across epidemic and pandemic threats, is providing over $4 million to fund four research projects At the same time, researchers are beginning to test the safety of a new vaccine candidate that does target the Bundibugyo virus. Last week, the WHO announced that trials for three vaccine candidates against Bundibugyo should begin by October or November. Last week, the WHO issued emergency guidance on the use of licensed Ebola vaccines for Bundibugyo, saying that everybody should be used only as part of a research protocol at this time. While we wait for real world data, a modeling study published last week in The Lancet Infectious Diseases estimated that the relative population effect and dose efficiency of a hypothetically partially cross-protective vaccine under operational, realistic constraints. During the Bundibugyo outbreak base case, vaccine effectiveness was 45% and included post-exposure protection against disease and death. The researchers concluded that a partially protective. Bundibugyo vaccines population level value will depend primarily on its rapid, broad delivery rather than how well it works amid an infectious disease outbreak, public health officials rarely have total certainty, and that's definitely the case here. But at this point, even partially effective vaccines are our greatest hope in reining in this virus that is ravaging a very vulnerable nation hobbled by armed conflict, population displacement and major public distrust of the government and medicine.

Chris Dall: Before we get to our final segment, let's talk about vector borne diseases, specifically the diseases carried by mosquitoes. Mike, as you and I know, it's been very dry here in Minnesota, but it has been much wetter in other parts of the country, like New York. Are we seeing any uptick in things like West Nile virus in these areas?

Dr. Michael Osterholm: Well, first of all, Chris, let me start out by saying that vector borne diseases, specifically mosquito borne diseases, has been an important topic in my public health life. Actually, as a high school student back in my hometown of Iowa, I actually worked during summers for the Iowa State Hygienic Lab, collecting mosquitoes around homes where a child had developed La Crosse encephalitis. And every day I would go out at 5:00 in the morning collecting the overnight sampling devices for the mosquitoes, which basically was a light trap that sucked the mosquitoes into these bags. And then each night I would go back out and reset the traps. I learned to have a great respect for what mosquitoes can do. And then, as some of you know, in 1996, my son at that time, a 16 year old, was critically ill with La Crosse encephalitis from a mosquito bite that he had gotten on our property out in the western suburbs. So every time I talk about mosquitoes and viruses, it's a very personal experience. So let's talk about West Nile. Peak West Nile virus transmission typically occurs in late July to September. So we're seeing increases in the number of cases in the US. But this is to be expected this time of year. The CDC reported an early start to the West Nile season this year back in June, but so far the number of cases for 2026 is well below the totals for 2025.

Dr. Michael Osterholm: Southwest United States has seen the highest number of cases of the 407 human West Nile cases reported as of September 1st, 88 have occurred in Arizona, 66 in California, and 46 in Texas. Together, that accounts for almost half of all the cases in the US so far this year. In comparison, New York has had only eight cases in 2026 and Minnesota has had four. To put this in context, in 2025, there are slightly over 2,000 cases, and in 2003, our worst year, there were almost 10,000 cases and 264 deaths. So over the 2026 season. I'm happy to report that we are well below what we've seen in the past. But keep in mind, this is an El Nino year, which drives shifts in temperature, rainfall and drought, all of which can impact West Nile virus ecology in different ways. And El Nino drives up temperatures, and warmer temperatures accelerate the replication rate of the West Nile virus inside the mosquito. This shortens the amount of time it takes for a mosquito to become infectious after feeding on an infected host, which is usually a bird in the case of West Nile. In regions where El Nino causes droughts, West Nile virus transmission often spikes, which seems somewhat inconsistent with the importance of water. But that's because the dry spells can actually turn flowing. Bodies of water, such as streams or rivers, into stagnant pools of water.

Dr. Michael Osterholm: Ideal breeding conditions for the type of mosquitoes that transmit West Nile. Lastly, heavy rainfall and flooding can also impact West Nile transmission as the increased precipitation expands standing water habitats, allowing the mosquito populations to rebound rapidly in early spring. That is why we had an earlier start to the West Nile season this year. Importantly, there are several steps our listeners can take to prevent West Nile as well as other mosquito borne viruses. The best prevention method is to avoid mosquito bites altogether. People should avoid outdoor activities during peak mosquito hours, which is dusk and dawn, or use an insect repellent registered with the Environmental Protection Agency that contains Deet or Picaridin. Removing sources of standing water around the home, such as birdbaths, flower pots, pet dishes and buckets, is another way to prevent mosquito bites for the entire household. Wearing long, loose fitting clothing can also prevent mosquito bites, as it can be difficult for the mosquito to reach the skin. As we progress further into the West Nile season, we will keep our listeners updated with the latest numbers. I must say, given the conditions we've seen in the summer, I'm somewhat surprised we don't have more West Nile activity. Specifically, given the intense rainfalls in some parts of the country as well as the high temperatures. But we'll see. The season's not done till it's done.

Chris Dall: Mike, now it's time for your favorite segment and mine. This week in public health history. What are we talking about this week, Mike?

Dr. Michael Osterholm: Well, so many kids went back to school this past week. I wanted to highlight two women who were pioneers in creating school nurse systems in America. Lillian Wald and Lena Rogers. This was back in the 1900s, when public schools were becoming more common. However, there weren't any school nursing programs in America yet. That was until Lillian Wald. Lillian was a public health nurse who worked in the Lower East Side in New York City. The neighborhood was mostly immigrant families, many of whom experienced extreme poverty. Families were packed into tiny apartments and buildings that were rarely maintained. All of this meant that disease often spread quickly and easily from resident to resident. This affected kids. Too many sick kids stayed home from school, missing class entirely. Some families couldn't afford to find treatment, so they never sent their kids back to school. Some schools even went so far as to purposely bar sick children from entering the classroom. Lillian observed all these problems and decided to develop a school nursing program. She started her experiment in October 1902, hiring nurse Lena Rogers. Lena's goal was to keep kids in school. In the first month of this experiment, Lena treated over 800 students and made over 130 home visits. She not only treated the children, but taught families about disease prevention and how best to stay healthy, sanitary and safe. Lillian and Lena's work was so successful. Lena's role became a permanent position in New York City schools. On November 4th, 1903, Lena became the first official municipal school nurse in America. Today, school nurses are a staple in every school district, and we wouldn't have that without the work of Lillian Wald and Lena Rogers. More than 100 years later, we still thank you both for your innovation, service, and dedication to your community and particularly to the kids.

Chris Dall: So Mike, what are your take home messages for today?

Dr. Michael Osterholm: Well, Chris, it should be obvious to everyone that at least that I think measles should lead the list. Things are going to get a lot worse in this country with measles. And I fear that our public health system will only become more dysfunctional in trying to deal with the impact of measles. There's no way around it. I'm convinced the politics of measles will challenge us in so many more ways than we ever thought of. Keeping facts as facts is so critical, and yet I see it slipping away into the debates about measles that we talked about today. Number two, it's all about getting vaccinated. Yep. Go out and get your COVID-19 now. The new vaccines are here. We may be seeing increasing activity in the next several weeks. Get it? But flu? I'd still wait until we can actually tell you that we're starting to see flu activity pick up. You want to head into the flu season with the highest possible protective level of antibody you can, and that means getting your shot in advance of, but not very far from the increasing activity of flu once it starts in that winter season. And finally, Ebola remains a major global public health challenge. Hopefully, the ear Ebola vaccine can reduce the number of serious illnesses. But in the meantime, the world has a severe global public health challenge on its hands.

Chris Dall: And lastly, Mike, in our last episode, part of the dedication was to Dolly Parton, who died recently. And I think we're returning to Dolly for our closing. Am I right about that?

Dr. Michael Osterholm: You are. And I think it's well deserved to be able to talk about her and what she did. And two consecutive podcasts today, I want to share with you something that Dolly did to mark her 80th birthday with a new charity single. This occurred just in January of this year, and I'm going to share with you information that's on country radio. She celebrated her 80th birthday this past January with a major philanthropic gesture rather than a party. The country music icon released a reimagined version of her classic song, "Light of a Clear Blue Morning," to support pediatric cancer research. I was just like her to do something like that for this special 50th anniversary recording. Dolly was joined by a powerhouse group of female artists Miley Cyrus, Lainey Wilson, Reba McEntire, and Queen Latifah. The updated version also featured David Foster on piano and backing vocals by the Christ Church Choir. True to the giving spirit that has defined her career, Dolly donated all the net proceeds from that song and his company music video to the Monroe Carell Jr Children's Hospital at Vanderbilt in Nashville, Tennessee. The funds were designated for the Hospital Pediatric Cancer Research Program. This contribution continued a long partnership between Dolly and Vanderbilt. She famously donated $1 million to the medical center in 2020 to support Moderna's COVID-19 vaccine research. A bit about the history of her life of a clear blue morning song. That song choice was deeply personal for her, as she originally wrote light of Clear Blue Morning in 1976 during a turbulent transition in her career.

Dr. Michael Osterholm: It was penned while she was separated from her longtime mentor and music partner, Porter Wagoner, to pursue a solo career, a move that sparked a famous feud and legal battle between the two. Dolly has often described the track as her song of deliverance, written when she needed to visualize a brighter future for herself. It originally appeared on her 1977 album New Harvest First Gathering. So let me share with you this very special song from Dolly Parton and the fact that it was a song that I think we all can embrace today. It seems to have more meaning by the day. "Light of a Clear Blue Morning" by Dolly Parton.

It's been a long, dark night and I've been waiting for the morning. It's been a long, hard fight. But I see the brand new day dawning. I've been looking for the sunshine. You know I ain't seen it in so long. And everything's going to work out just fine. And everything's going to be all right. That's been all wrong. Because I can see the light of a clear blue morning. I can see the light of a brand new day. I can see the light of a clear blue morning. Oh, and everything's going to be all right. It's going to be okay. It's been a long, long time. Since I've known the taste of freedom. Those clinging vines, they had me bound. Well, I don't need them all. I've been like a captured eagle. You know an eagle was born to fly. Now that I have won my freedom like an eagle. I am eager for the sky. Because I can see the light of a clear blue morning. I can see the light of a brand new day. I can see the light of a clear blue morning. Oh, and everything is going to be all right. It's going to be okay. "Light of a Clear Blue Morning" by Dolly Parton.

Thank you again for joining us with the podcast. I hope we were able to give you some information that you find helpful and interesting. And again, I want to thank you for all the outreach and for the support that you continue to share with us. I want to thank the podcast team. I can't tell you how much it means to me to be able to be part of this team. And I want all of you. Despite the fact that the day seemed to get more challenging as we go on, never forget that kindness in the end is the most powerful thing we can know. And so I hope that from that perspective, even though it may seem a bit unnatural, do a kind act every day, an unexpected kind act. See how much those around you get from that and even yourself, how much it means to you. So thank you. I look forward to seeing you in two weeks and, uh, hopefully you have a safe, wonderful time. And all I can say is be kind. Thank you.

Chris Dall: Thanks for listening to the latest episode of the Osterholm update. If you enjoyed the podcast, please subscribe, rate, and review wherever you get your podcasts. And be sure to keep up with the latest infectious disease news by visiting our website, CIDRAP.umd.edu. This podcast is supported in part by you, our listeners. The Osterholm Update is produced by Sydney Redepenning, Elise Holmes and Ruby Guthrie. Our researchers are Cory Anderson, Meredith Arpey, Leah Moat, Emily Smith, Clare Stoddart, Angela Ulrich and Mary VanBeusekom.