ACS Alumni in Science

From classrooms to cutting-edge labs, ACS graduates are making waves in the world of science—and their journeys often begin right here on campus. As part of our ACS Alumni in Science series, we spotlight remarkable alumni like Darina Spasova ’05, now Senior Director of Pharmacology at Replicate Bioscience. This feature is part of The Science LAB fundraising campaign, which aims to expand opportunities in STEM for ACS students by enhancing the school's science facilities. Together, these efforts reflect the power of science education - and the lasting impact of investing in young minds with curiosity, courage, and the drive to explore the unknown.

If you had to explain what you do to a curious 10-year-old, how would you describe it?

Inside the castle lives a powerful team of guards and knights called your immune system. Their job is to protect the castle from invaders—like viruses, bad bacteria, or anything trying to make you sick. My job is to study these guards and knights and understand how they work together to prevent disease. I’m kind of like a coach for them, helping them get stronger and smarter. Understanding how these guards or knights work together helps us make vaccines that can prevent deadly illness. A vaccine is like a wanted poster or a training mission delivered to the guards before a real battle. It shows them what the enemy looks like and teaches them where the enemy’s weaknesses are and how to fight it—without anyone getting hurt. So, when the real invader tries to sneak in, your guards are trained, armed, and ready. My job is like the general or wizard, inventing new technologies that can teach your guards how to recognize and remember these invaders. I use something called self-replicating RNA. Self-replicating RNA is one of these training missions that I show the guards, but it’s special because it copies itself again and again inside the castle, making it easier to spread the message faster and farther—so even the guards in the far-away towers get the warning before the invaders come. So, my job is to understand how the castle’s defenses work, to write the training manual and design the missions, and to help the knights fight better and remember better.

What inspired you to pursue a career in science and how did your time at ACS influence your path?

I’ve always been curious about biology. As a child, I wanted to be a doctor, but during my time at ACS, I became especially interested in how different organ systems work together. I was lucky to have teachers—especially a few American and Canadian ones—who recognized and supported my curiosity. They encouraged me to ask questions, even the ones they didn’t always have answers to, which gave me the confidence to keep asking questions throughout my life and career. It was in 9th grade biology and even geography class that I first realized how much I enjoyed trying to understand how things in nature and in our bodies work—not just how to fix them when they’re broken. That’s when I knew I wanted research to be part of my future.

What’s one project or discovery you’re especially proud of? What breakthrough in your field excites you the most right now and why?

I’m particularly proud of my PhD work, which demonstrated that our bodies can't effectively remember certain infections without the help of the beneficial microbes in our gastrointestinal system. This discovery helped lay the foundation for my interest in T cell memory (how some of those "knights" we talked about in Question 1 remember invaders) and in vaccines. One of the most exciting breakthroughs in my field—and something I’m currently working on—is self-replicating RNA. Unlike the COVID vaccines, which used linear mRNA (a type of genetic message that tells cells how to make proteins), self-replicating RNA delivers the same instructions but can do so at doses that are 1,000 to 100,000 times lower. That means fewer side effects while still achieving the same, if not better protection. It's also significantly cheaper to produce and has more capacity—so it can include instructions to fight multiple diseases in one shot. This opens the door to
multivalent vaccines that can protect against several infections at once. It also lays the groundwork for therapeutics for chronic diseases.

Can you share a favorite memory from your science classes or teachers at ACS?

I always had a great relationship with my biology teachers, but my 9th-grade biology teacher stands out as particularly memorable. He was close in age to us students, which made his classes feel approachable and fun. When he taught anatomy—often an awkward topic at that age—he made it engaging and even funny. What truly set him apart, though, was his honesty and humility. He was never afraid to admit when he didn’t know the answer to a question. Instead of brushing it off, he’d go read up on it and come back the next class to share what he’d found. Sometimes the answer was straightforward, but often it wasn’t—and he would explain why science doesn't always have clear-cut answers and how uncertainty is part of the process. I vividly remember asking a question about evolution during one of our anatomy lessons—how a particular organ system evolved or was conserved across species. He didn’t know, and instead of pretending he did, he made an educated guess and invited me to stay after class so we could look it up together. We explored the topic, and he helped me understand the technical language as we learned side-by-side. That moment had a lasting impact on me. It was the first time I saw a teacher be truly vulnerable by admitting they didn’t know something—and it showed me that curiosity and the willingness to learn are at the heart of science. The way we discovered the answer together is what sparked my love for biology.

Why do you believe it’s important to invest in science education today?

Science education isn’t just about learning facts or memorizing formulas—it’s about learning how to think. At its core, science teaches us how to be comfortable with not knowing while at the same time seeking the truth. It helps us learn how to ask questions, form hypotheses, test ideas, and learn to be comfortable with discovering that we were wrong. A strong science education helps students understand complex systems and build comfort with the fact that most problems in life don’t have simple answers. It also encourages collaboration and peer feedback—learning to say, “Can you check my thinking?” and being open to correction. That’s how real discovery happens. Importantly, science teaches us to recognize and stop falsehoods. In a world overflowing with misinformation, the ability to distinguish what’s true from what’s simply loud or popular is essential. Science gives us the tools to evaluate claims, test assumptions, and protect ourselves and others from harm caused by disinformation. Failure, too, plays a critical role. In research, experiments fail the majority of the time—and that’s not a sign of weakness. It’s how we learn. When students understand that failure is part of the process, they grow more resilient and more curious, not less. Investing in science education means investing in a generation that can think independently, challenge misinformation, and solve problems in thoughtful, evidence-based ways. It fosters not just knowledge, but integrity, humility, and courage—all essential for navigating the challenges of the modern world.

At ACS, our students aren’t just learning science - they’re using it to make a difference. They have the talent and drive to solve real‑world problems and they are tackling ambitious projects. Our alumni’s impressive achievements in scientific research and innovation are a testament to the strength of their education—and with your support for The Science LAB fundraising campaign, we can empower the next generation of changemakers. Join us in investing in the future by donating today at: https://acs.bg/giving/donate