Episode 194: Bending Not Breaking

Chris Dall: Hello and welcome to the Osterholm Update, a podcast on COVID-19 and other infectious diseases with Doctor Michael Osterholm. Doctor 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, Doctor Osterholm draws on nearly 50 years of experience investigating infectious disease outbreaks to provide straight talk on the latest infectious disease and public health threats. 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. At a September 21st event at the White House, President Trump made several evidence free claims about the childhood vaccine schedule and how many vaccines young children receive. Among them was the idea that the combined measles, mumps and rubella vaccine should be split into three separate vaccines. He would later share this idea on social media. Needless to say, his comments alarmed many in the public health community. Fast forward a few weeks, and that suggestion has now been echoed by the acting director of the CDC. I call on vaccine manufacturers to develop safe monovalent vaccines, to replace the combined MMR, and break up the MMR shot into three totally separate shots, Jim O'Neill said in a post on the social media site X.

Chris Dall: The comments by the president and acting CDC director are just the latest example of how ideas long held by vaccine critics, have now taken hold at the highest levels of the federal health apparatus and could result in significant and dangerous changes to the country's vaccine infrastructure. On this October 16th episode of The Osterholm Update, we'll explain why the idea of breaking up the MMR vaccine into three shots is so alarming to public health experts. We'll also provide an update on the government shutdown. Bring you up to speed on the still unclear Covid vaccine picture. Discuss a recent study on Covid vaccine efficacy. Assess the current picture for COVID-19 and other respiratory viruses. Examine the spike in whooping cough cases in several states. And take a look at the uptick in H5N1 avian flu activity in US poultry. We'll also answer an ID query about herd immunity. Fill you in on CIDRAP Vaccine Roadmaps project and bring you the latest installment of This Week in Public Health history. But before we get started, as always, we will begin with Doctor Osterholm's opening comments and dedication.

Dr. Osterholm: Thanks, Chris, and welcome back to everyone in the podcast family. It's good to be with you again. I want to thank all of you who have sent us recent emails or cards with information that you would like to see us cover or just thoughts you have about the podcast. In the near future, will be announcing to you that we are undertaking a review of our podcast activities at CIDRAP and how we might expand upon them, how we can make them more effective for you. And so, stay tuned, because we want your input. It's very important to us. And in that regard, I want to open today's podcast session here with a comment that I can never say quite enough. And that is thank you to the podcast team that helps put this together. Chris, you have been so important in all of this. Sydney Redepenning and Elise Holmes, who are both co-producers of this podcast, as well as the team members. Thank you, thank you, thank you. I realize I tend to be kind of a focus of this podcast, but it would be nothing compared to what it is now if it weren't for this team. So, with that, a really, truly heartfelt thank you. So now let me get back to the old format here. Starting out as we always do, I'd like to dedicate this episode to a particular group of individuals who are recently recognized for their incredible work and noteworthy medical discovery. We dedicate this episode to the 2025 Nobel Prize winners in Physiology or Medicine, Doctor Mary Brunkow, Doctor Fred Ramsdell and Doctor Shimon Sakaguchi.

Dr. Osterholm: They were awarded the Nobel Prize this year for their work on peripheral immune tolerance, which illuminated how the body learned not to attack itself and give insight to how failures in this delicate balance can lead to autoimmune diseases. Their research has opened up entirely new avenues for therapy. Thanks to their discoveries, we now have new tools to turn down the immune system when it attacks the body and turn it up when it fails to recognize threats. A revelation for treating conditions from rheumatoid arthritis to cancer. We applaud their work and the recognition it was recently awarded. Discoveries like these, the kind that change medicine and save lives, begin far from the spotlight. They begin in classrooms and laboratories where researchers gather to study the unknown, and where experiments fail a hundred times before one insight changes everything. The work of Brunkow, Ramsdell and Sakaguchi is a triumph of persistence and a powerful reminder that medical breakthroughs are not miracles. They are the result of decades and decades of dedicated, well-supported research. We often talk about progress in terms of outcomes lives saved, disease cured, technologies invented. But the real foundation of that progress is the culture of inquiry that makes it possible. Every research grant, every mentorship, every open access journal, and every student given the chance to ask bold questions contributes to the momentum of discovery. These systems of knowledge building are luxuries. They are simply lifelines. At a time when science is politicized and funding for basic research is under major attack, we cannot afford to forget that the health of our future generations, our kids and our grandkids, depends on what we invest in today.

Dr. Osterholm: A science education, research infrastructure and the freedom to investigate those ideas and share the results, whatever they may be. So, to all the 2025 Nobel Laureates, we honor your work and to the countless researchers, students, and educators who labor every day, often without recognition, we dedicate this episode to you as well. Now, jumping into a little bit of a lighter topic. As such, for those who would like to take their one-minute break, here you go. Right now, I'm happy to report that today Minneapolis does have some sun. It rises at 730am in the morning, sets at 625pm in the evening. That's ten hours, 55 minutes and 15 seconds of sunlight. We are losing sunlight at about three minutes and one second a day. And for anyone who's been out driving around, you recognize the sun is at a little lower in the sky now, more likely to come in that front windshield than it was during the summer when the sun was at a much higher level. In Auckland, New Zealand, at our famous Occidental Belgian Beer House on Vulcan Lane, sunrise this morning was at 635am sunset 7:38 p.m. That's 13 hours, two minutes and 16 seconds of sunlight. Yeah, they got us beat by a bit now. And you're gaining sunlight at two minutes and 17 seconds a day. So, we'll keep following this. We can sure feel it getting darker and darker here, but I gotta always remember, as soon as it gets really dark here, it starts to get light again.

Chris Dall: So, Mike, let's start with the government shutdown last Friday. Media reports indicated the Trump administration was laying off more than a thousand employees from the Department of Health and Human Services in response to the shutdown. Among those cut were diseased outbreak investigators, officials who'd been in charge of the CDC's response to the measles outbreak, and the entire editorial staff of the CDC's flagship publication, the Morbidity and Mortality Weekly Report. Then on Saturday, many of these same people were informed they had not been fired after all. Mike, even with some of these people being brought back, this administration seems intent on decimating the CDC. Your thoughts on what happened over the weekend?

Dr. Osterholm: Well, Chris, I have enough thoughts right now to fill an entire notebook about what's happening. It's heartbreaking, heartbreaking, infuriating, and irresponsible. That's what I think about this whiplash of organizational chaos. For an administration that was supposed to be all about good business practices, the best in the business. It seems to me that this is an example of exactly how not to run a business. The events of this weekend were catastrophic to the integrity, success, and morale of CDC. It wasn't just another round of predictable layoffs. This was an intentional gutting of the agency. As you said, it was more than a thousand employees who were abruptly terminated via email. Entire offices and teams across more than a dozen CDC divisions were wiped out. Among those impacted are public servants working in global health, immunization and respiratory diseases. Infectious disease alert systems. Data systems. The Morbidity and Mortality Weekly Report, injury Prevention, and the entire CDC Washington office that serves as the public health liaison to Congress. More than 1300 employees were told they were being laid off. That's not just bureaucratic reshuffling. That's cutting muscle and bone from the very infrastructure that keeps Americans safe. Yes, the good news is that over the weekend, many employees received emails saying their firings were a coding error. But is it really good news that there is no plan or rebuilding strategy, that we've also been told that additional cuts could still be coming? That public servants are being fired and rehired in mass, with no respect for the turmoil caused, or the vision for how to build and maintain a public health system that our country needs and deserves, regardless of what your political persuasions may be.

Dr. Osterholm: What does this all mean? When you gut the CDC, even temporarily, you disrupt outbreak response. You weaken support to state and local health departments who rely on CDC guidance and data. You risk missing early warning signs of disease spread, are unable to communicate quickly and clearly to the medical and public health community. And let's be honest, there is no coherent strategy here. No restructuring plan, no evidence-based justification. This is another example to silence the CDC, to suppress the voices of scientists and public health experts in favor of political control. That's not just irresponsible. Frankly, I believe it's dangerous when politics starts dictating what science can say, especially in the middle of disease outbreaks, widespread vaccine hesitancy and rising rates of chronic disease, we all lose. We lose trust, we lose time, and eventually we also lose our lives. So yes, I'm relieved that some of these professionals have been reinstated. But the fact is that this happened at all should set off alarm bells. A strong, independent CDC has never been a Partisan issue, nor should it be. It is all about public health, necessity, and the health of our children and grandchildren in this country.

Chris Dall: So, let's turn now to the status of the updated Covid vaccines, because we continue to get a lot of questions from our audience. Since our last episode, CDC Acting Director Jim O'Neill has accepted the recommendations of the Advisory Committee on Immunization Practices and said the agency is now applying individual based decision making or shared decision making to COVID-19 vaccination. So, Mike, can you explain again for our listeners what that means and what kind of questions it raises?

Dr. Osterholm: Well, Chris, this is a bit of a complicated topic, so let me try to break it down into some component pieces and explain what it means. First of all, the role of the ACIP is to determine how to best optimize vaccine use in the US. Historically, they've considered questions such as how safe and effective are the vaccines, and particularly at different ages or underlying health conditions, how serious is the disease the vaccine prevents? How many people would get the disease the vaccine prevents if we didn't have the vaccine. And then make recommendations for vaccination that maximize individual and population benefit. The ACIP may elect to make routine catch up and risk-based recommendations or individual based decision making, otherwise known as shared decision making. With routine catch up and risk-based recommendations, these become the default recommendations for everyone in a given age group or risk category. This default means that unless there are contraindications to vaccinate an individual, the committee recognizes the vaccination maximizes the benefits to both the individual and to population Health. This is the case for childhood vaccines like MMR, DTaP and the Hib vaccine and other types of vaccine recommendations is a recommendation based on what we call shared clinical decision making. The recommendation is intended to prompt a discussion between a patient and their provider to discuss risk of disease and benefits of vaccination. Unlike routine recommendations, shared clinical decision-making vaccinations are not recommended for everyone in a particular age group or everyone in an identifiable risk group. In general, shared clinical decision-making recommendations are made when there is evidence that the individual may benefit from the vaccination, but that the broad vaccination of all people in that group is unlikely to have a population level impact.

Dr. Osterholm: The risk benefit vaccination is most favorable for individuals who are at increased risk for severe disease, and lowest for individuals who are not at increased risk. There are five recommendations for shared clinical decision making. They are first the meningococcal B or Menb vaccination for adolescents and young adults age 16 to 23 years. Second is hepatitis B, a vaccination for adults aged 60 years and older with diabetes. Third, HPV vaccination for adults aged 27 to 45 years. Next, Pneumococcal conjugate vaccine for adults aged 65 and older. And then now, any additional doses of Covid vaccination for people who are moderately or severely immunocompromised. The main difference between the two types of recommendations is the default decision to vaccinate for shared clinical decision-making recommendations, there is no default. The decision about whether or not to vaccinate may be informed by the best available evidence of who may most benefit from vaccination the individual's characteristics, values and preferences, the healthcare provider's clinical discretion, and the characteristics of the vaccine being considered. Because there is not a prescribed set of considerations or decision points to guide the decision-making process. It can be challenging for providers and patients alike to interpret the recommendations. Importantly, the decision to recommend a vaccine for routine use versus shared decision making is not related to any concerns about vaccine safety or to the informed consent process.

Dr. Osterholm: In fact, the type of recommendation is entirely separate from the point of care informed consent process that is legally and ethically obligated and must occur with any vaccination, regardless of recommendation type. For providers and patients, shared clinical decision making recommendations provide numerous challenges that may include the following. First, limited time for the provider to become aware of relevant disease prevalence, vaccine safety, and vaccine efficacy data necessary to help patients make an informed decision. Second, a lack of access to a consistent primary care provider, resulting in limiting opportunities for extended or ongoing conversations regarding the benefit of certain vaccines. Next, uncertainties around demand, which can make it difficult for some providers to stock vaccines recommended by shared clinical decision making. Next, a lack of reimbursement for counseling sessions and finally, a lack of shared health records. That means counseling between the pharmacist or even a primary care provider in another health system, and therefore the patient information may be incomplete. Importantly, the coverage requirements under the Affordable Care Act applies to shared clinical decision-making recommendations when they have been adopted by CDC and are listed on the immunization schedules. These vaccines are generally required to be covered by group health plans and health insurance issuers offering group or individual health insurance coverage without imposing any cost sharing requirements. I hope this explanation provides some sense of why do we have two different categories of vaccines? Those which are routine catch up or risk-based recommendations, and those which are individual based decision making. Yes, I agree, it's a bit complicated.

Chris Dall: And interestingly, Mike, Politico reported that this position seems to allow pregnant women to receive the Covid vaccine. Even though Kennedy announced last spring that Covid vaccines would no longer be recommended for pregnant women.

Dr. Osterholm: Well, Chris, you know, the longer I'm in this business, the more I begin to think I know less about what's going on today than I did years ago. But at least for now, it does appear that COVID-19 vaccines remain recommended under shared clinical decision-making during pregnancy. The ACIP did vote to advise that all adults get COVID-19 shots through shared clinical decision making. And as you mentioned in your question, Chris, ACIP did not specifically vote on whether the shot should be administered during pregnancy. Despite Mr. Kennedy announcing last spring that the Covid vaccines wouldn't be recommended for pregnant women. The CDC website reflects the ACIP vote that the COVID-19 vaccines be recommended based on shared clinical decision making. Interestingly, the CDC website shows that COVID-19 vaccines are recommended during pregnancy due to the conclusive increase in risk for at least one severe COVID-19 outcome for those who become infected during pregnancy. As I mentioned in the last question, the new guidance also could mean that pharmacies can administer the vaccine during pregnancy. Of course, this depends on some state laws and regulations, and that almost all insurers must cover the shots with no cost sharing, which would in effect expand access. The bottom line is there is significant mixed messaging here, but fortunately it looks like, at least for now, the vaccines will remain available during pregnancy.

Chris Dall: And while we're on the topic of Covid vaccines, I want to ask you about a study that came out last week in the New England Journal of Medicine on the efficacy of last season's Covid vaccines in US veterans. What did we learn from that study?

Dr. Osterholm: Chris, there are two main takeaways that I have from this study. The first is that protection against Covid from these vaccines surely isn't as high as we'd like it to be. We've talked about that before. And the second takeaway is these vaccines still do a great deal to reduce serious illness, hospitalizations and death. This study analyzed data from the Veterans Affairs Saint Louis health care system, using electronic health records to compare the two groups, one with over 164,000 individuals who received COVID-19 and influenza vaccines on the same day, and another group of over 131,000 individuals who received only the influenza vaccine. Before I go on, let me just say a word about this group of research from the Veterans Affairs Saint Louis health care system. They are simply among the very best of all the epidemiologic researchers in the country. And I give them great credit for how they did this study, how they've done their past studies, and what they're able to provide us with in terms of very solid information. The study in question here spanned from September 3rd through December 31st, 2024. Both groups were followed for six months or until an outcome of interest occurred, i.e. COVID-19 associated emergency department visit, COVID-19 associated hospitalization or a COVID-19 associated death. After adjusting for potential confounding variables including demographic and socioeconomic characteristics, health behaviors, preexisting conditions, and health care use scores, as well as the possibility that the influenza vaccine only group later received a COVID-19 vaccine. The researchers assessed the effectiveness of the Covid vaccine. They found that the vaccine effectiveness waned over the six-month period.

Dr. Osterholm: At six months, the vaccine was 29% effective against Covid related emergency department visits, 39% effective against Covid hospitalizations and 64% effective against Covid deaths. Clearly, this vaccine is not as effective as we'd like it to be. But you've heard me say that time and time again. This is not a great vaccine, but it's a very good vaccine. What do I mean by that is that it doesn't necessarily prevent you from becoming infected or from transmitting the virus, but it is very important in reducing the risk of serious illness, hospitalizations and deaths, particularly among those who have underlying health conditions. And this is supported by the results of the study. The group found that the vaccine effectiveness waned over the six-month period. At six months, the vaccine was 29% effective against Covid related emergency department visits, 39% effective against Covid hospitalizations, and 64% effective against Covid deaths. I'll take a vaccine to beat those odds any day of the week. If you are eligible to receive your dose of COVID-19 vaccine and haven't done so yet, please prioritize getting your vaccination. As I've said, it's not a perfect tool, but it sure can go a long way in preventing serious illnesses. That said, waning protection is also why investment in research into more broadly protective and effective coronavirus vaccines is so very important. This is something we've been working tirelessly on here at CIDRAP, and I look forward to sharing more about what we're doing in this area in just a moment.

Chris Dall: Now to the focus of my introduction, the idea of breaking up the MMR vaccine into three separate vaccines. Mike, is there any reason you know of why public health officials or vaccine makers for that matter, should be considering this? And are you concerned that this idea that the combined MMR vaccine is unsafe, an idea that's coming from the very highest levels of our government, that this is going to further contribute to already declining vaccination levels?

Dr. Osterholm: Chris, let me be very, very clear. There is no evidence based immunologic or safety reason to break up MMR into three separate vaccines. When acting CDC Director Jim O'Neill called for the separation of MMR vaccine last week, he offered no scientific rationale for the recommendation because, frankly, there is none. Again, there is none. His comments come on the heels of the September meeting of the CDC's Advisory Committee on Immunization Practices, or ACIP, during which it's recommended that the combined measles, mumps, rubella, and varicella, or MMRV vaccines no longer be offered to children aged 12 to 47 months and instead be given a separate shots. As Doctor Jake Scott of Stanford Medicine wrote in a recent CIDRAP op ed, no safety data justify abandoning a program that has protected millions of children for more than 50 years. What we have instead is the acting CDC director resurrecting a fraud's discredited theory, while measles spreads throughout the American communities at a rate not seen in decades. The reason that I, Doctor Scott, and many other public health experts are so alarmed by this are multifold. For one, separate measles, mumps and rubella vaccines aren't available and won't be for years. Merck stopped making its single strain vaccines in 2009, so pharma companies would need to start over conducting new clinical trials, updating manufacturing plants and getting FDA approval for three different vaccines. A second reason is that the burden that parents would have to assume in taking time off from work to take their child to a doctor's office three separate times.

Dr. Osterholm: This is particularly problematic for families with limited resources, for whom work absences and healthcare access can be significant barriers to vaccine series completion. For example, a 2017 study showed that 69% of kids who have received combined vaccines completed their routine childhood vaccination series, while only half of those who received separate vaccines did so. These factors could definitely lead to declining vaccination rates, putting other people at risk for infection. What's more, we have plenty of evidence supporting the benefits of the MMR vaccine. For example, a clinical trial found better immunity against mumps with the combined MMR vaccine than with single strain mumps vaccine. While concentrations of mumps antibodies post-vaccination of 77 to 85% against different viral strains, compared to only 56 to 66% with single strain vaccines. In fact, on its website, CDC acknowledges that combining vaccines are safe. Don't weaken immune responses and have distinct advantages. Writing that, quote, children should be given their vaccines as quickly as possible to give them protection during the vulnerable early months of their lives. And fewer office visits save families time and money and can be less traumatic for the child. Looking beyond the United States, no other country that wants to eliminate measles, mumps, rubella use separate vaccines, and the World Health Organization elimination strategy relies on combined vaccines. And let me add one additional piece of information may help you understand that the comments that we're now just pumping our kids full of vaccines and somehow that's dangerous is simply not true.

Dr. Osterholm: Despite the increased number of diseases, we're able to vaccinate for today versus decades past, children are actually exposed to fewer immunogenic proteins and sugars that help trigger immune responses because vaccines today are so much cleaner. For example, five routine vaccines given in 1960 expose children to 3217 immunogenic proteins and sugars. Again, 3217. Vaccines today total expose children to fewer than 170 proteins and sugars. Of note, the infant immune system handles thousands of new antigens daily from normal environmental exposure. This is far more than the approximate 170 antigens in all vaccines combined today. So, this information again also debunks the need widespread of these vaccines out by single dose. As we all know, vaccination is especially critical amid this year's US measles outbreak, which has sickened more than 1560 people in dozens of outbreaks and killed at least two children. 92% of those infected have been unvaccinated. Right here in Minnesota, as of today, we have 20 new cases of measles reported. The CDC announced last week that the ACIP has now established a panel to review the safety and efficacy of US childhood vaccination schedules. Among the topics the group will review is the administration of different vaccines. At the same time, knowing that a number of ACIP members or vaccine critics, I fear they will echo the recommendation to separate the MMR vaccine, leading to a total unnecessary loss of life, disease and disability. Oh, I hope I'm wrong.

Chris Dall: Let's take a look now at the latest COVID-19 data. Mike, what is Covid activity looking like around the country at the moment?

Dr. Osterholm: With the government shutdown, the CDC has not updated their usual Covid data. Fortunately, there are other ways we can monitor respiratory activity across the country, including Yale School of Public Health's Pop Hive, which compiles data from several sources to provide a comprehensive respiratory update. I also want to mention Caitlin Rivers and her team at Force of Infection. They post a weekly outbreak update on Substack. During the government shutdown, they're going to all 50 states and the District of Columbia's websites to monitor Covid, flu, and RSV activity. This is a tedious task, and we're very grateful for the work that Caitlin and her team are doing. Based on these sources, we have a pretty good idea where we are. I am pleased to report that, as expected, activity continues to decline across the country for Covid, and I feel confident saying that we're on the other side of the most recent wave. Wastewater concentrations continue to decline across the country based on data from wastewater scan. They monitor nearly 150 wastewater sites across the country for 12 pathogens. On their scale, the national COVID-19 wastewater concentration is considered to be at a minimum level and has decreased for the last three weeks. Emergency department visits continue to decrease across the country.

Dr. Osterholm: I cannot provide the overall percentage of ED visits that have resulted in a positive COVID-19 test for the past few weeks, but most states were seeing percentages in the 0.3 to 1.8% range. I'll remind you that during our last episode, 1% of ED visits in the US resulted in a positive Covid test. So with levels continued to decline, we can expect that nationally we're below that 1% mark. Unfortunately, we do not have a weekly death update this week. Based on previous Covid waves and the fact that deaths are a lagging indicator. I would have expected that we'll be reporting either the peak in weekly deaths associated with this most recent wave, or we'd be on the other side of the peak. It'll be noteworthy to report these numbers when we receive CDC updates again. We also don't have a variant update this week, but last we knew, the XFG variant accounted for nearly three quarters of US cases. And there was another variant that seemed to be challenging it. I know this was a bit of a scarce update. Please know we're monitoring all the data we can. For now, I think we're in an increasingly better spot in terms of Covid at the moment.

Chris Dall: Since we're starting to get into viral respiratory season. What about flu and respiratory syncytial virus?

Dr. Osterholm: Similar to the Covid situation, the data is very limited, which is especially disappointing considering the timing of the typical respiratory season. But from the data we do have, I can tell you that both flu and RSV levels remain low across the country. There are some very early signs that activity may be increasing in some areas, with RSV activity increasing in young kids specifically. Again, I want to say thanks to Caitlin Rivers and her team at Force of Infection for their work compiling state level data. Several states are experiencing very slight increases in influenza and RSV activity. Based on emergency department visits and test positivity, four states Alabama, Hawaii, Oklahoma and Texas are experiencing slight increase in both flu and RSV activity. Four states are experiencing slight increases in flu, but not RSV. These states are Connecticut, New Mexico, Ohio, and South Dakota. There are several more states that are experiencing increasing RSV activity and specifically in the 0- to 4-year-old age group. And those are all in the South or northeast US, including Florida, Kentucky, Louisiana, Maryland, Massachusetts, Pennsylvania, Rhode Island, South Carolina, and Virginia. Unfortunately, while the shutdown is occurring, I would recommend staying on top of your state health departments reporting to stay updated on the latest trends.

Dr. Osterholm: With all this considered, I think it's now time to think about getting that flu shot. As you know, I've been holding off waiting for flu activity to pick up, and I think the next 2 to 3 weeks we could see quite a bit of flu pick up, particularly as we get more into the Thanksgiving holiday season. So, depending on how long it may take you to get in to get your shot, now is the time to make those appointments and do that. Let me just close on one last note here. We are seeing around the world increasing influenza activity that I think is quite important. Right now, Japan has actually just declared an emergency in some areas because of a major increase with influenza in the last 3 to 4 weeks. So, in fact, at this point, we can expect the flu season to light up. And given what we've seen in Japan, at least right now, we may be in for a notable flu season.

Chris Dall: One bacterial infection we are seeing increases in in several states is whooping cough or pertussis. Among them is Florida, which has seen an 81% increase in whooping cough cases this year compared with 2024. And we're seeing this trend globally as well. Mike, what's going on with whooping cough?

Dr. Osterholm: Well, Chris, let me just add some context first to this issue. When we talk about the numbers of cases right now, they surely are rising. But based on historical norms, they're still low. In 1940, there was an estimated 200,000 new cases of pertussis in this country, or what's often been referred to as whooping cough. 9000 of these individuals died, mostly young kids. I am concerned that while we're not going to see numbers like that for a while, we are on track for another challenging pertussis or whooping cough here. And I say another challenging pertussis year because last year brought us significant increases in cases. Cases in 2024 in the US were over six-fold higher than in 2023. And while pertussis cases have historically ebbed and flowed from year to year, seeing two bad years in a row could signal that something bigger is going on. A potential sustained rise in cases due to declining pertussis vaccine uptake. This is why I'm so concerned that cases in Florida, 81% higher than what we saw last year in 2024, which was already a record pertussis year in that state. And as you mentioned, Chris, the issue is not just limited to the US. The W.H.O., European region and Western Pacific region both also saw a significant increase in pertussis in 2024 compared to 2023, a 3.4 fold increase in the European region, and more than a 12.5 fold increase in the Western Pacific.

Dr. Osterholm: It's tough to say how much of this is a result of the pathogen's natural ebbing and flowing, and how much is the result of a decline in vaccine uptake. I think we're likely seeing both of these at play to some extent, but the key takeaway from this is that vaccination is a powerful tool against pertussis. Let me help those who are not clinicians better understand the pertussis vaccine composition, because it varies by the age of those for which the vaccine is recommended. DTaP, which is capital D, capital T, small A, capital P is the full-strength vaccine for children less than seven years of age. This includes diphtheria, tetanus, and acellular pertussis vaccines. A second vaccine, Tdap capital T small d small a small p has a smaller dose and is for children greater than seven years of age, adolescents and adults as a booster. So, when you're in getting your vaccine, don't be surprised if you hear about both of these different vaccines. So again, for children, five doses of DTaP are recommended between ages two months to six years of age, followed by the first Tdap between ages 11 and 12.

Dr. Osterholm: From there, adults need Tdap. The capital T small d small a, small p boosters every approximately ten years, and are also recommended in the third trimester of every pregnancy. While the Tdap booster is affordable and accessible, uptake is challenged not only by growing vaccine refusal but frankly, by a lack of awareness. Many Americans lack primary care providers who can help them keep track of what vaccines they need during adulthood, and pertussis is often not on the front of mind for many individuals Being up to date is not only important for your own protection against bacteria, but particularly for those around young children, both parents and adults who are at most risk for severe infection. As we brace ourselves, it could be another very challenging pertussis season. Please do your part to ensure you're up to date on your vaccinations and encourage the people in your life to do the same. There's nothing worse than when a grandparent transmits a pertussis infection to one of their grandchildren, and that grandchild becomes severely ill. I've seen that you don't want that to happen.

Chris Dall: After a pretty quiet summer, there's also been a significant uptick in H5N1 flu in commercial poultry here in the United States. Do you have a sense of what's driving this, Mike?

Dr. Osterholm: Well, Chris, as I've been saying since 1997, if I could only understand a little bit about H5N1, I'd be a much smarter man. This is an infection that, as you've heard me talk about it in the last year as it relates to the infections in bovine, and the fact that it continues to be an avian related transmitted virus, it's still unclear what this virus is going to do in terms at least human infections, in terms of the animals, as we surely could expect, H5N1 is back right on time with the fall migratory season. In the last 30 days, there have been 42 flocks confirmed with highly pathogenic avian influenza, 26 commercial and 16 backyard flocks totaling 6.3 million birds affected. They've occurred in 13 states, including Arkansas, Idaho, Iowa, North Carolina, Michigan, Minnesota, Montana, Oregon, South Dakota, Utah, Virginia, Washington, and Wisconsin. This count includes five outbreaks of commercial turkey farms in Minnesota, ranging from 31,000 to 73,000 birds affected, as well as commercial turkey farms in Iowa, Michigan, and Utah, each with at least 30,000 affected birds. It also includes two notable outbreaks in commercial egg producers one in Wisconsin affecting nearly 500,000 birds, and another in Washington, affecting nearly 2 million birds. There have been a number of cases confirmed in migratory birds. 554 in the last 30 days, including 159 in Michigan, 112 in Minnesota, 91 in Kansas, 52 in New York, and ranging from blue winged teal, Canadian geese, black and turkey vultures, and mallards. There has only been one case identified in dairy cattle in the last 30 days, and that was in Nebraska's first known case.

Dr. Osterholm: The uptick in H5N1 activity is somewhat expected. However, there is one notable difference, its later this year. And why? Because we've had unusually warm weather here in North America, particularly in the central and northern states, and therefore migratory bird activity is a bit slower this year. We're now seeing activity that is sometimes two and three weeks later than we had seen in previous years. As you know, we have been seeing these outbreaks in every migratory season, both spring and fall. And we saw the widespread outbreak in dairy cattle that started in March of 2024. But let me remind everyone that back in July, the CDC declared it was ending its emergency response to H5N1, citing a drop in both human and bovine cases. I think that's still probably true. I think we would be picking up more bovine cases if they occurred. But I'm also certain that there are a number of migratory bird cases that we're missing right now. The birds that have been tested are often ones that are quite ill on the ground, or have actually died and have been tested. So, I expect that we're going to continue to see this migratory season the same situation of H5N1 pinging the commercial poultry flocks in this country, and that any day could be the day that that virus change that occurs in that bird population is the next one that caused a pandemic. I hope that that never happens. But right now, we're giving this virus every chance the genetic roulette table, I can imagine.

Chris Dall: Now it's time for our ID query. This week we heard from Michelle, who asked, what is the percentage of the community that needs to be vaccinated to keep a viral disease at bay? For example, measles. Even if a child is vaccinated against measles, could this child contract measles if the community has a low vaccination rate?

Dr. Osterholm: Well, Chris, let me just point out, this concept is something that's even often challenging for graduate students to understand in terms of what it means. Herd immunity, sometimes called community immunity, is a form of population level protection that occurs when enough people are immune to a disease that makes it hard for the infection to continue to spread. In other words, if a high enough proportion of the population is immune. People who remain unvaccinated are not at risk of being infected because the pathogen is not circulating and people are not exposed. Think of it as something like rods in the reaction. If you have enough immune rods in the reaction, it stops it or at least slows it down. The proportion of the population that needs to be vaccinated or immune to induce this type of protection, called the herd immunity threshold, depends on how infectious the pathogen is to begin with. You might have heard that the basic reproductive number or the r naught value, which is the number of people one infected person will go on to infect in a population that is fully immunologically naive, meaning they have no protection against the virus from vaccination or previous infection. For a virus like measles, the R naught is somewhere between 12 to 18, meaning that an unvaccinated population every person could infect 12 to 18 others on average. For comparison's sake, the r naught of Ebola is around 1.5 to 2.5.

Dr. Osterholm: Big difference. The higher the R naught value, the higher the proportion needed to be immune to halt transmission. For measles, we know the threshold is at least 92 to 94%. This is an estimate based on a number of assumptions, but it allows us to conceptualize how many people need to be vaccinated or immune from previous infection to stem measles transmission, which is why we're seeing outbreaks across the country in communities that have lower vaccination rates. Even in states with overall vaccination rates in the 92 or higher range, there exists many pockets of schools, neighborhoods, cities and counties with much lower vaccination rate creating opportunities for viral transmission. Right here in the state of Minnesota, we actually have schools that are in the 40 to 50% level of vaccination. That means that those school districts surely are at risk for seeing a measles outbreak in their schools. The answer to Michele's second question is yes. It is possible for a vaccinated child to contract measles during a measles outbreak. Though close, the vaccine is not 100% effective. Two doses of MMR vaccine are about 97% effective at preventing measles. One dose is only about 93% effective. These are incredible levels of protection and seen almost with no other vaccine. While being vaccinated greatly reduces the risk of becoming infected with measles if exposed, being in a community with low vaccination rates surely increases the risk of being exposed.

Chris Dall: Mike, over the past five years we've been doing this podcast. Our listeners have probably heard you talk about Vaccine Roadmaps Project, which is separate from the more recent Vaccine Integrity Project. But I understand that you have an update for us.

Dr. Osterholm: Chris, as you just noted, there are many of you who know that CIDRAP launched the Coronavirus Vaccines Roadmap in 2023, which aims to track research progress towards the development of broadly protective coronavirus vaccines around the world. Sars-cov-2, the virus that causes Covid, is only one of many coronaviruses capable of causing human disease. Others include SARS, which caused an epidemic in 2003, as well as MERS, which is a cause of a similar type illness after exposure to dromedary camels in certain regions of the world. We're very fortunate for both of those viruses that we're able to basically contain those outbreaks, while many people had very low levels of infection. We did see some who were what we call super spreaders. They were challenging. But yes, again, we were able to bring this under control. And let me note that if you look at the case fatality rate for both SARS and MERS, it's anywhere from 15 to 35%. Think of that of those who got infected, anywhere from 15 to 35% of people would die. So, these are also very, very important pathogens for particularly for the future and what might happen with the next pandemic. And let me add that there are also numerous known and unknown coronaviruses circulating in bats that could eventually evolve to infect humans in the future, and could also transmit a virus that not only is highly infectious, but could kill at the rate that we saw both MERS and SARS. There are over 100 candidates in the vaccine landscape that we've identified, although many of these are likely to face roadblocks given the current funding crisis for scientific research in the United States, which has implications far beyond domestic research.

Dr. Osterholm: As we have discussed extensively on this podcast, CIDRAP launched a coronavirus R&D progress tracker, which cites research progress in the published literature and reports from international health organizations such as the W.H.O.. Each citation in the Progress Tracker is aligned to a strategic goal and milestone from the roadmap. Both the vaccine landscape and progress tracker are live on the CIDRAP website now, and are entirely open source and freely available to anyone who might be interested in learning more about this critical work. We will actually include a link from the show notes, so that you can go directly to either the landscape or Progress tracker, and we will continue to update these resources as new information becomes available. We'd surely like to thank the Coalition for Epidemic Preparedness Innovations, or what is known as CEPI, for funding this work and serving as expert partners on this project. Also, we'd like to express gratitude towards the CVR task force composed of global experts in virology, immunology, vaccinology, animal models and policy who have reviewed all the content in our Landscape and Progress tracker. And last but not least, I want to thank our team who works in this area. Their work has absolutely been foundational in terms of the world's understanding of the coronavirus vaccine landscape and what we can do today. And just to note, CIDRAP is committed to having vaccines one day that are highly protective against infection and illness and can be available in a timely way to take the potential impact of a pandemic off the table.

Chris Dall: Finally, it's time for this week in public health history. Mike, what are we celebrating today?

Dr. Osterholm: Chris, today what we're celebrating is a what in public health history. It's a critical research study that I anticipate very few of our listeners know about, but it provides the foundation for evidence on cardiovascular disease that we still rely on today. There is a thread here that will tie back to the rest of the podcast. After the conclusion of World War Two, the American public health system turned its attention to the number one cause of death of its citizens: heart disease. Very little was known about cardiovascular health and its risk and protective factors at the time. What is now known as the National Institute of Health, designated a study that would follow every day people for years to track how different lifestyles and genetic factors would impact heart health. After careful consideration, Framingham, Massachusetts, a small town about 30 minutes outside of Boston, was chosen. This was not entirely at random. Framingham was known to have a relatively stable population where families stayed for multiple generations. They also had a history of cooperating with public health project. In 1917, the town had participated in an effort to develop national strategies to control tuberculosis. The town was also close to other research and healthcare infrastructure, making the extensive testing more logistically feasible. The study officially began in October of 1948, with more than 5200 men and women who volunteered. These average individuals, teachers, factory workers, business owners took part in extensive testing of their blood pressure, cholesterol and heart rhythms. They were also asked about lifestyle factors such as diet, exercise and smoking. Data became actionable results in the coming years in the mid-1950s.

Dr. Osterholm: Not only was the term risk factor coined in the public health lexicon, but it was confirmed that smoking was a key risk factor for heart disease. Early results also established that elevated blood pressure and cholesterol led to increased risk. By the 1960s, it was clear that high blood pressure also increased the risk of stroke. By 1971, 23 years after the study began, the research enrolled a second generation of participants. More than 5100 additional volunteers were enrolled, all children and spouses of the original cohort. In 1978, the study authors published findings that defined clinical criteria for congestive heart disease, now known as the Framingham Criteria. By 2002, a third generation of about 4000 volunteers were enrolled. These were the grandchildren of the original cohort. In 2003, additional volunteers were also brought on to represent a wider diversity of participants. Racial and ethnic backgrounds, making results more generalizable to the whole country. This study is still ongoing, making it one of the longest cohort studies in history. Newer technology has expanded its reach into genetic sequencing and has now added additional components on aging, such as dementia and Alzheimer's risk. I think we often take for granted some basic facts like high blood pressure impacts heart disease risk, but we need research like this to provide a framework for the basic science. This makes the current cuts and chaos at HHS, NIH, and CDC even more destructive and frustrating. But I want to close by thanking the thousands of Framingham volunteers. Your time and dedication have surely helped make the world a better and healthier place.

Chris Dall: Mike, we have covered a lot of territory today, from government shutdowns to heart health. What are your take home messages for today?

Dr. Osterholm: Chris, I think it's fair to say that I could use this first takeaway as the takeaway one, two and three. In short, we are in a government policy and practice freefall, but we don't have to just take it. Our work, for example, with the Vaccine Integrity Project, the work we're doing with the roadmaps and you will soon hear about several new initiatives that we're undertaking in the future. It's really important that people understand that this does not have to be a time of total darkness. We can still do so much and we will continue to put that position forward. We won't be able to do everything, but we can do something and I believe that we can make a difference. My second take home message Covid has leveled off, but there's a hint of flu starting to come. And so, I think now is the time to start thinking about getting your flu vaccination scheduled. It's no longer too early. I think now is the time to get it. And finally, my third take home. More now than ever. We need each other. Tell us how we can help you be a better source of information on this podcast. And yes, you can get involved at the local level with immunization related work groups in each of your towns, cities, and counties. We will again put on the show notes a link to a number of such groups that would welcome, with open arms, volunteers to come and help in their promotion of vaccines in their community. I hope you will consider doing that. This is important. We need everyone to come forward to help support a world where vaccine science is fairly portrayed, and the actual benefits of that work will be recognized.

Chris Dall: Mike, I know we don't have a closing song today, but I understand you have some quotes you'd like to share with our listeners.

Dr. Osterholm: Well, Chris, given the tone of this podcast, which I hope by now has at least been somewhat evident about the concern of what's happening with our basic science and research, I hope that the closing here gives us some food for thought. I've actually picked quotes from two very notable scientists who gave so much of their lives to making the world a better place for us. The first one is Madame Marie Curie, born on November 7th of 1869. She died July 4th of 1934. And you may know, she was a world expert in the whole area of radiation and radiation benefits and radiation risk. Unfortunately, she actually died from aplastic anemia due to likely all of her work with X-rays. She was also the only woman ever in history to receive two Nobel Prizes, one in physics and one in chemistry. Only five such individuals have ever received two Nobel Prizes, the other four being men. She was quoted as saying once, we must not forget that when radium was discovered, no one knew what it would prove useful in hospitals. The work was one of pure science, and this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science.

Dr. Osterholm: And then there is always the chance that a scientific discovery may become like radium benefit for mankind. The second person that I'm citing today is someone who I actually had the opportunity to meet and spend some time with my career and was so taken by his brilliance, his genius, and his kindness. I'm speaking of Jonas Salk, the father of the modern polio vaccine. And again, just to put into context, the year I was born, there were over 50,000 cases of polio in this country, including 21,000 cases of paralytic polio. That's in my lifetime. He was born in October 28th, 1914 and died on June 23rd, 1995. Actively working at that time on an AIDS vaccine. He really hit a whole new standard for scientific principles when he was once interviewed by the famous reporter Edward R Murrow, and Murrow asked him, who owns the patent to the polio vaccine? Salk replied, well, the people, I'd say there is no patent. Could you patent the sun? What a humble, amazing guy. He said some people are constructive, if you like. Others are destructive. It is this diversity of humankind that results in some making positive contributions and some negative contributions. It is necessary to have enough to make positive contributions to overcome the problems of each age.

Dr. Osterholm: Thank you, Madame Marie Curie. And thank you, Jonas Salk, for your very thoughtful words. At a time when we more now than ever, need to understand the importance of good data and scientific research, I want to thank all of you for joining us again. I want to acknowledge the podcast team. Thank you so much for making this podcast happen. And to all of you listeners out there, we really do want to hear from you. We want to get better. We want to be able to be more helpful at this time. And recognizing fully that it's a confusing time. It's a challenging time. But we're going to get through this and we're going to do it hanging together. And as you've heard me say in previous podcasts, our motto is CIDRAP today is we will bend, but we will not break. And today we need all of you to think like that. We need all of us to come forward and do what we can to address the challenges of the day. Thank you so much for being with us. I hope you all have a good two weeks Healthy, safe and enjoyable. And again, remember how important it is to be kind. Please. Now is the time to 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.umn.edu This podcast is supported in part by you, our listeners. If you would like to donate, please go to CIDRAP.umn.edu/support. The Osterholm Update is produced by Sydney Redepenning and Elise Holmes. Our researchers are Cory Anderson, Meredith Arpey, Leah Moat, Emily Smith, Clare Stoddart, Angela Ulrich, and Mary Van Beusekom.