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As vaccine hesitancy and misinformation grows, Kris Ehresmann ’84 is using her decades of experience as a public health leader to teach new generations of Oles why following the science matters.

Kris Ehresmann ’84 remembers the exact moment she decided to teach a course on vaccines at St. Olaf College. 

It was December 2024, and she had just finished reading a story in the New York Times about how the lawyer helping Robert F. Kennedy Jr. pick federal health officials for the incoming Trump administration had petitioned the government to revoke its approval of the polio vaccine. 

Ehresmann, an epidemiologist with decades of experience as a public health leader, was stunned. The polio vaccine is widely considered one of the greatest public health successes in history, preventing an estimated 20 million cases of paralysis in children over the last four decades and nearly eradicating the virus worldwide. And while the petition to revoke the polio vaccine garnered the most headlines, the lawyer working with Kennedy had also filed a petition seeking to pause the distribution of 13 other vaccines. 

“I’ve dealt with the anti-vaccine movement and vaccine misinformation throughout my career, and it has certainly accelerated over time,” Ehresmann says. “But the mere idea that the incoming leaders of the U.S. Department of Health and Human Services might not support vaccines was unthinkable.” 

So she turned to what she has long believed is the best way to combat challenges to public health policy: ensuring the next generation of leaders understand the science that serves as its foundation. She put together a proposal for a January Term course on vaccines at St. Olaf, where she has been teaching in the Public Health Studies Program since retiring from her role as the director of the Infectious Disease Division of the Minnesota Department of Health (MDH) in 2022. 

“Our students really need to be grounded in the science of vaccines because it’s so foundational to public health,” Ehresmann says. “Aside from clean water, vaccines have saved and changed more lives than any other public health measure.” 

To accomplish this, she designed a course that begins with an overview of the history and development of vaccines, and then delves into the basics of vaccinology, how vaccines are licensed and recommended, the vaccine safety system in the U.S., the way vaccines are used to prevent and control disease around the world, and the factors influencing vaccine hesitancy. 

Ehresmann’s depth of expertise makes her uniquely qualified to teach such a course. She oversaw the State of Minnesota’s Immunization Program for 22 years and served as the president of the Association of Immunization Managers, a national organization that brings together state immunization program leaders to strategize ways to improve vaccine coverage. She also served as a voting member of the federal Advisory Committee on Immunization Practices (ACIP), an expert group that advises the U.S. Centers for Disease Control and Prevention (CDC) on its vaccine recommendations, and most recently as a voting member of the National Vaccine Advisory Committee (NVAC), which provides peer reviews and guidance to the assistant secretary for health, who serves as the director of the National Vaccine Program. 

In addition to her own expertise, Ehresmann drew on the relationships she’s developed throughout her career to provide students with additional perspectives and insights on the impact vaccines have on public health. Paul Offit, a pediatrician who co-invented the rotavirus vaccine, joined the class virtually from Children’s Hospital of Philadelphia, where he directs the Vaccine Education Center. Mike Osterholm, an epidemiologist who leads the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota — and who rose to national prominence for the knowledge and guidance he provided during the COVID-19 pandemic — spoke to students about the Vaccine Integrity Project that he helped launch. Several MDH staff members also visited to share insight into state and federal immunization programs, as well as public health emergency preparedness. 

“I love public health, and I really believe in it. And so it’s an honor to get to teach the next generation. I tell my students, ‘You are going to change the world.’” —Kris Ehresmann ’84

Henry Floyd ’28, one of the 32 Oles who managed to get a seat in the filled-to-capcity class, says the opportunity to hear directly from these experts was incredibly impactful. 

“They really elevated the information from being something learned in a textbook to something tangible, run by real people,” says Floyd, a statistics and data science major who plans to work in public health or for a private health care company. 

While Floyd came into the course with a unique level of experience gained from working as a pharmacy technician, he wanted to better understand the science behind vaccines. 

“I knew a lot about vaccine history and immunology, but I knew very little about vaccine policy,” he says. “This class educated me on the specific policies a lot more, and how much effort is put into quality control and studying these vaccines.”

Johnny Jelatis ’27, a biology and chemistry major with a concentration in public health studies, agrees. 

“An important realization we shared was coming to appreciate the many, many steps that are taken to ensure a vaccine is safe and effective before it ever hits markets,” says Jelatis, who plans to attend medical school. He notes that because public health is as much about policy and regulation as it is about science, this course provided a crucial understanding of both when it comes to vaccines. 

Several other Oles say the class will help them better care for their future patients. Salah Abdulkarim ’26 will start medical school in the weeks after graduation. A biology major with a concentration in public health studies, he has been involved in the St. Olaf Emergency Medical Technicians since his first year on campus. For the past several years he has interned at the Dana Farber Cancer Institute in the Medical Oncology Laboratory of Mark Murakami ’02, where he worked to visualize clinical data for a preliminary immunotherapy trial targeting a rare lymphoma. He knew this class would complement his coursework and already deep range of experiences in health care — and he felt Ehresmann’s expertise would provide a valuable learning experience. 

“Though I do not know what medical specialty I plan to pursue, this class has reinforced my understanding of what it means to be a physician and the role they play beyond direct patient care,” he says. “Health literacy is a largely overlooked issue within the U.S., and physicians need to spark conversation that helps communities and policymakers make informed decisions based on objective data.” 

As a nursing major planning to pursue a career in pediatric nursing, Julia Pomerleau ’26 wanted to learn more about vaccine-preventable diseases and childhood immunization schedules. The course really underscored for her that vaccines don’t just benefit individuals — they boost global economies, reduce the overall use of treatments like antibiotics, and provide important layers of protection for the most vulnerable. 

“Staying up-to-date on your vaccines contributes to herd immunity — that is, population immunity,” she says. “This protects the most vulnerable of populations, including babies, pregnant women, immunocompromised folk, and older adults. We can continue to protect these individuals and save lives by receiving vaccines.” 

Ella Romans ’29 took a similar lesson away from the course. “The most important thing I learned is the honestly inconceivable number of lives that have been saved by vaccines — about 150 million in the past 50 years,” she says. 

The course also helped illuminate a paradox this has created. “Vaccines are so effective at preventing disease and saving lives that it’s astounding — but their success is also the reason why many people see them as unnecessary now,” she says. “Because we’ve eliminated or reduced so many deadly diseases, they’re not a common occurrence anymore and people don’t realize how catastrophic they are.”

She points to the very disease that spurred Ehresmann to create the course: polio. 

“This disease paralyzed thousands of children, and now we don’t see it, save for a case in 2022,” Romans says. “Misinformation can spread like wildfire, especially in the age of social media, and it’s very difficult to overcome this knowledge gap with accurate information when many people have trouble discerning the difference between what’s truthful and what’s not. This is the greatest danger to vaccines.”

On their last day of the class, Osterholm told students that this is precisely why the information they had learned throughout the month-long course was so important. 

“Right around the time I was born, we had 55,000 cases of polio in the United States,” he told the class. “A boy who sat across from me in first grade died from measles.” 

For decades, those experiences provided regular Americans with a firsthand understanding of the role that vaccines play in protecting people from serious illness and death. But in recent years, anti-vaccine philosophies and behaviors have spiked, Osterholm says, and vaccination rates have dropped. The U.S. is currently on the brink of losing its measles elimination status due to record surges in cases and sustained, linked outbreaks — closely on the heels of Canada, which officially lost its measles elimination status last year. 

All of this comes amid shifting federal health recommendations as agencies like the CDC and National Institutes of Health experience widespread staffing turnovers, and the work of the ACIP has been frozen. 

Against this backdrop, Osterholm has pulled together a team of experts, including former CDC leaders, to create the Vaccine Integrity Project. Their work is focused on providing trusted, independent, science-based information to support vaccine safety, effectiveness, and policy in the U.S. 

“I refuse to accept the fact that there’s nothing we can do in the face of the challenges we are experiencing to public health policy,” he says.

“Aside from clean water, vaccines have saved and changed more lives than any other public health measure.” — Kris Ehresmann ’84

Like Ehresmann, he believes the best hope lies with the next generation of health care leaders.

“I hope all of you decide to go into public health — we will need you,” he told students in the class. “Whatever I can do, it will pale in comparison to what you can do.” 

And, he notes, they are lucky to have the opportunity to learn from Ehresmann. 

“One of the very, very best decisions that I have ever made is hiring Kris at the Minnesota Department of Health. She has been an absolute gift to the state of Minnesota. You are lucky to have her.” 

Ehresmann feels she’s really the lucky one. 

“I love public health, and I really believe in it,” she says. “And so it’s an honor to get to teach the next generation. I tell my students, ‘You are going to change the world.’” 

As students arrived for their last day of class on a cold January day, a brightly colored card was at each of their seats. In addition to a personal note of encouragement for each student, Ehresmann had included a quote on each card from scientific pioneer Sir Geoffrey Vickers that reads “I believe that the history of public health might well be written as a record of successful redefinings of the unacceptable.” 

She hopes students use that as inspiration to answer the question it begs. 

“I ask them: ‘How are you going to go out there and redefine the unacceptable in the world?’” she says. “Because I know that’s what they will do.”