Jason S. McLellan specializes in understanding the structure and function of viral proteins, including those of coronaviruses. His research focuses on applying structural information to the rational design of vaccines and other therapies for viruses, including SARS-CoV-2, the novel coronavirus that causes COVID-19. McLellan and his team collaborated with researchers at the National Institute of Allergy and Infectious Diseases’ Vaccine Research Center to design a stabilized version of the SARS-CoV-2 spike protein, which is a key element in at least four COVID-19 vaccines to have either reached Phase 3 clinical trials or been approved for emergency use (those from Pfizer and BioNTech; Moderna; Johnson & Johnson and Janssen Pharmaceutica; and Novavax). McLellan also co-developed a vaccine candidate for RSV (respiratory syncytial virus) that is currently in human trials.