The mRNA technology used to create the first two COVID-19 vaccines, from Pfizer-BioNTech and Moderna, will undoubtedly change the course of vaccine development for years to come. The synthetic mRNA platform works like a software program that carries the genetic code of the spike protein, an important and easily recognizable portion of SARS-CoV-2. When the code—delivered in a nanoparticle—is injected, the human body begins to make antibodies that recognize and protect against the virus. Peter Palese, PhD, expects successful vaccines that use conventional methods will not be far behind those based on an mRNA platform. Within the Icahn School of Medicine at Mount Sinai’s Department of Microbiology, he and his colleagues Adolfo García-Sastre, PhD, and Florian Krammer, PhD , are working on a new low-cost COVID-19 vaccine that uses an engineered Newcastle disease virus vector. They expect to begin a phase 1 safety trial in January. Dr. García-Sastre is Director of the Global Health and Emerging Pathogens Institute, and Dr. Krammer is Mount Sinai Professor in Vaccinology.