A personal commitment to public health
Stories of research and clinical care from two leading experts in pneumococcal and pediatric infectious disease
March 19, 2025

Nearly all of us have caught a seasonal cold, but some infectious diseases can pose significant health risks. Research plays a critical role in advancing prevention and treatment strategies for infectious diseases.
Our researchers are at the forefront of scientific innovation, working to address the diseases that threaten our most vulnerable populations around the world. Heather Platt, M.D., and Marissa Wilck, M.D., two Merck scientists specializing in pneumococcal and pediatric infectious diseases, shared their journeys into medicine and their reflections on the critical role research plays in improving public health.
What drew you to a career in infectious disease research?
Dr. Wilck: “I grew up in rural South Africa and had to choose a career at 18. Knowing amazingly little about what it would encompass, I chose med school because of my love of science and wanted to do something meaningful with my life. In my clinical years, I saw infectious diseases all around me, which drove me to specialize in infectious diseases.”

Dr. Marissa Wilck
Dr. Platt: “I chose internal medicine for my residency because I loved learning the broad scope and it allowed me to explore a variety of interests, particularly in infectious diseases.
One of my first patients during my internship year was a 75-year-old lady who had pneumonia and was brought into the ICU because her blood pressure was starting to drop. Within an hour, she needed full support for breathing and blood pressure with central lines and intubation. That was a pivotal moment for me to understand the complexity and impact of infectious diseases like pneumococcal disease. I later completed a fellowship in infectious diseases and witnessed advancements that made me want to pursue research.”
Are there any common misconceptions about infectious diseases like pneumococcal disease that you aim to overcome?
Platt: “Anyone can get pneumococcal disease. You’re at increased risk depending on your age or certain medical conditions. Some people can become very ill, very quickly. I think Marissa and I have both seen serious cases of complications from pneumococcal disease, like pneumonia and meningitis.”
Wilck: “In my clinical years, I remember seeing previously healthy people becoming very sick with pneumococcal disease. I have a particular patient in mind that I think about; I remember looking at him and thinking, ‘How can this strong man who was healthy just two or three weeks ago get so sick from this bacteria?’”
SEE ALSO: Facts about invasive pneumococcal disease and how infection spreads
A look at the numbers
- Approximately 13.7 million people worldwide died from infectious diseases in 2019.
- Infections such as pneumococcal disease can lead to potentially severe health issues, like pneumonia, sepsis and meningitis.
- Pneumonia impacts millions of people worldwide each year.
What makes infectious disease research unique compared to other areas of medical research?
Wilck: “I find infectious disease research fascinating because it encompasses many aspects of human health and society. Infectious diseases affect everyone, and the social and economic impacts touch all communities. To me, this has reinforced the critical importance of researching prevention measures. We have the opportunity to make such a difference.”
How do we balance research in prevention versus treatment?

Dr. Heather Platt
Platt: “There’s a lot of satisfaction that comes from knowing that you can be a part of preventing disease. But as infectious disease physicians, we see how prevention and treatment both have a role. Choosing to spend time on prevention strategies is as worthy as the time that our colleagues are spending on researching treatments for these diseases. We can put our collective heads together because we’re all fighting for the same thing.”
What inspires you about our team?
Wilck: “Merck has such a deep history and legacy in infectious disease research and innovation. As a team, we can make things happen in a way that we could never do as individuals. I’m proud to be part of that effort.”
Platt: “At Merck we have the opportunity to work in different therapeutic areas, and that allows me to appreciate the different elements of research that are needed in order to improve the burden of these infectious diseases. It isn’t just one product or one patient. Marissa and I have crisscrossed paths in our research in pneumococcal and pediatric infectious diseases at Merck, but we’ve both had the opportunity to positively contribute to public health. It’s an honor and a privilege to be a part of offering prevention options.”
We’ve been working to combat global health threats caused by infectious diseases for more than a century. Learn more about our work in infectious disease research.