As mRNA-based COVID-19 vaccines are deployed to protect hundreds of millions of people across the world from the deadly global pandemic, the University of Pennsylvania scientists whose research breakthroughs laid the foundation for swift vaccine development have been awarded the 2021 Lasker-DeBakey Clinical Medical Research Award. Here, mRNA vaccine pioneers Drew Weissman, MD, PhD, and Katalin Karikó, PhD, share the story behind their development of this groundbreaking technology, and what it means for the future of medicine.