As an infectious disease epidemiologist, PhD student Kristin Andrejko has focused her life on public health and helping communities on the path to wellness. Now, with an eye towards public health policy and a focus on how vaccines serve to protect those most vulnerable to the ravages of disease, she finds herself on the front lines of some of the most pressing global public health battles—from malaria to COVID-19.

“The past 16 months have certainly highlighted the incredible value of vaccines in improving all aspects of our physical, social, and economic health. As an epidemiologist, my day job is to quantitatively analyze public health programs like routine vaccination campaigns to help mitigate the risk of future infectious disease outbreaks.”

Andrejko’s path to global public health is one heavily influenced by her time at CA. She credits experiences in sixth-grade science teacher Aaron Rothrock’s class as igniting an early passion for the scientific method—one that translated into years serving as a counselor at CA summer science camps where she enjoyed making science accessible and engaging for students.

In Gray Rushin’s Advanced Chemistry class, she discovered the hard-earned reward of working through thorny scientific challenges. Building on those interests, an experience with the Student Global Leadership Institute (SGLI) in Punahou, Hawaii, the summer before her 12th-grade year, offered a transformative introduction to the broader concepts of public health.

Andrejko still remembers a pivotal question posed by Dr. Linda Rosen­—then-Director of Hawaii’s State Department of Health, during an SGLI panel on urban health­—that would ultimately set her professional course. “She started her talk by asking us to define health. I think most of us said, ‘health is the absence of disease; health is when you’re not sick.’ At some point, she stopped us and said, ‘health is more than just the absence of disease—it’s about being well.’

It was a lightbulb moment for Andrejko. “I had this epiphany: you don’t have to wait until someone is sick to help them.”

After the seminar, Dr. Rosen suggested that Andrejko look into the work of Dr. Paul Farmer, whose efforts on the intersection of health, human rights, inequality, and infectious diseases earned him the label “the man who would cure the world.” She was immediately hooked, intrigued by the social justice dimensions of public health.

Back at CA, Andrejko discussed her fascination with Farmer’s work with college counselor Laura Sellers, who suggested that she look into Notre Dame because of the ethos of social justice embedded in the school’s mission.

She applied, and upon being offered admission, made her way to South Bend to interview with Professor Joseph A. Buttigieg, then the Director of the Hesburgh-Yusko Scholars Program—a leadership development scholarship that helps social justice-oriented students develop their passions and pursue their purpose.

During the conversation, Andrejko gushed about her experience at SGLI, her interest in global health, and the excitement she felt about the prospect of doing the sort of work on infectious disease outbreaks like the Haitian tuberculosis epidemic described in Tracy Kidder’s Mountains Beyond Mountains.

“He paused me and said, ‘Kristin, that’s great, but you must think about sustainability.’ It was something I hadn’t even considered. It prompted me to take a more critical look. So much of the work in global health, while often well-intentioned, doesn’t necessarily lead to good outcomes. For example, if you go on a mission trip to build a bridge—but don’t involve any local stakeholders in the design or building process—when that bridge breaks after the mission trip leaves, who will fix it?”

As the conversation continued, Buttigieg walked her through the myriad ways that actions and outcomes play out in the global health arena. “It shaped my thinking for how I wanted to establish a role for myself in global health, and the types of organizations—those with ethical community engagement, capacity building, and sustainable practices—with which I wanted to align myself.”

A good question

Accepted into the Hesburgh-Yusko Scholar Program, which afforded her guaranteed funding for summer learning opportunities, Andrejko immediately set to work with Professor Buttigieg, identifying health organizations that were making sustainable impacts in communities around the globe.

Ultimately, she found herself working with One Sun Health, an organization dedicated to sustainable, locally-driven solutions to improve health and well-being in rural South Africa. Working alongside community health workers and local health departments, Andrejko saw firsthand the impact of malaria on rural South African communities and gained critical insights into the importance of earning public trust and respecting local knowledge in the implementation of public health initiatives. A new interest bloomed—this time for field research and for learning more about the communities she sought to help. With new knowledge came new questions.

“During many of the conversations that I had with community health workers in South Africa, some began to ask, ‘if we have all of these great vaccines for measles, flu, and other infections, why don’t we have a vaccine for malaria?’”
It was a good question­—one to which Andrejko didn’t have a response. Intrigued, she set out to find the answer.
Returning to Notre Dame, she developed an independent research project to interview vaccine researchers from across the globe who were hard at work developing vaccines to combat malaria. Her project took her to Switzerland, where she met with vaccine researchers at prominent think tanks and the World Health Organization (WHO)—an experience she sums up as “incredible.”

The following summer, Andrejko returned for an internship in the WHO’s Immunization, Vaccines, and Biologics Department. “It was one of the most transformational experiences of my life,” reflects Andrejko.

“At WHO, I witnessed the critical role that evidence-based research plays in developing and informing life-saving public health policies. I gained insights into how health policy decisions are made on a global scale.”

She recalls assisting with the preparations for a WHO conference commissioned to update policy recommendations for pneumococcal vaccines that prevent pneumonia. “It was very exciting to have all these experts in one room, actually looking at the policy and seeing whether or not they have the necessary scientific evidence to change it,” shares Andrejko.

“It showed me the robust evidence base that is required to inform any public health policy decision, and gave me a new appreciation for what it takes to move the needle on any sort of policy decision in public health. And, I realized that I needed to learn more research methods so that I could design and implement the types of studies that would ultimately address evidence gaps identified by policymakers.”

The Public Health Paradox

At WHO, Andrejko felt her interest shift away from an intense focus on malaria towards infectious disease epidemiology more broadly. Increasingly, she found herself at the intersection of public health and policy, interested not only in how specific diseases affect different populations, but how to develop policies that prevent outbreaks from occurring in the first place.

“I saw the public health paradox. When public health works, we don’t see it; when you prevent outbreaks from occurring, people forget how terrible a disease is. As a result, they stop following preventative measures—like getting vaccinated—and pathogens predictably return with terrible consequences. I gained an intimate appreciation for how critical it is that policymakers understand the value of public health.”

Led by her new interest, Andrejko sought to bolster her skills beyond what was offered by her Science Business major. Because Notre Dame didn’t offer an undergraduate program in epidemiology or public health, she begged her way into any and all of the university’s graduate-level courses on infectious diseases, public health, and epidemiology.

Her persistence and drive paid off, ultimately resulting in an internship at the U.S. Centers for Disease Control in Atlanta. There, in the Division of Parasitic Diseases and Malaria, she worked on observational studies evaluating the safety of various drugs to prevent malaria in pregnancy. “I loved the work I was doing. Working alongside the CDC researchers, I learned so many new epidemiological methods.”
It was an informative experience that ultimately made clear her next step.

“Taking a finding and converting it into a scientific publication that can inform policy was such a rewarding process,” explains Andrejko. “But it also made me realize that I still lacked the skills to actually design and run these sorts of epidemiological studies on my own—and I knew that’s what I wanted to do in the future.”

Facing forward

With a solid sense of what she wanted to learn, Andrejko began seeking a PhD program—and a mentor who would guide her studies in the emerging field of pneumococcal vaccines, and how they intersect with public health policymaking. She found that mentor in Dr. Joseph Lewnard, an Assistant Professor of Epidemiology at University of California, Berkeley’s School of Public Health, who uses mathematical and statistical modeling to study the transmission of infectious diseases and how vaccinations and public health policy improve community health.

Ambitiously, under the mentorship of Lewnard, in the fall of 2019, Andrejko set out to evaluate the role that pneumococcal vaccines play in reducing trends in antimicrobial resistance, a study now published in The Lancet-Microbe.

“Vaccines are the most cost-effective and life-saving public health intervention—and not just because they prevent disease outbreaks,” offers Andrejko. “One of the biggest existential threats we face is antimicrobial resistance (AMR). If we can use vaccines to reduce the number of infections that require treatment with antibiotics, we reduce the opportunities for pathogens to develop resistance.”

And then 2020 happened…

Almost overnight, Andrejko found her focus shifting once again­—from the public health impact of pneumococcal vaccines to the impact of vaccines to combat SARS-CoV-2, the virus that causes COVID-19. She’s focused on determining the effectiveness of COVID-19 vaccines in different populations, the ways vaccines are staunching the spread of viral variants, and the factors driving COVID-19 vaccine acceptance.
In some ways, it has been an easy shift. “The methods I was using and the questions I was asking before COVID are very similar to the ones that I’m studying now—the pathogen just changed.” she explains. “It was incredibly rewarding to see our vaccine-effectiveness study presented alongside others at a recent CDC meeting in June that evaluated whether booster shots for COVID-19 will be necessary.”

A new role

Now, leading a team of researchers for a statewide study on COVID-19 vaccine effectiveness with the California Department of Health, coupled with the teaching responsibilities of being a doctoral candidate, Andrejko has become the mentor.

“I am a graduate-student instructor for a foundational course that is often the first experience undergraduates have with global health. I get to introduce them to this whole new world of public and global health that they didn’t know existed,” offers Andrejko.

“So often, students are taught that if you care about health and if you like science, you should become a physician or a nurse or a kind of a health professional that works with individual patients. I get to show them that working in public health provides the opportunity to systematically improve health at the population level, but doing so successfully is challenging because it requires involvement not just from physicians and epidemiologists but from a wide range of stakeholders, like architects and engineers who design public health infrastructure such as safe housing, water, sanitation, and hygiene. Public health is exciting because it sits at the intersection of many of these disciplines.”

As for what’s next for Andrejko? When she finishes her doctorate, she hopes to work in a public health setting on the local, state or federal level, so she can continue to learn from those around her.

“I hope, in 30 or so years, that I can serve on the sort of boards that evaluate research evidence, creating the policy decisions that make a meaningful impact for everyone. But who knows? The beauty of public health is that people end up in different places and on different paths. I’m excited about what might come next for me.”