Dr. Walker is senior vice president and chief medical officer at Novavax, Inc., a US-based global company advancing protein-based vaccines. A specialist in internal medicine and pulmonary and critical care medicine, Dr. Walker has more than 30 years of experience in drug and vaccine development within the private and public sectors. He joined Novavax from Meissa Vaccines, Inc., where he led the development of RSV and COVID-19 vaccines. Prior to Meissa, Dr. Walker was Chief Medical Officer at the Biomedical Advanced Research and Development Authority (BARDA) in the U.S. Department of Health and Human Services. He and his team provided clinical development expertise to medical countermeasure programs, including Operation Warp Speed for COVID-19 vaccines and therapeutics, and to federal emergency responses to Zika, Ebola and influenza epidemics. Dr. Walker earned his doctor of medicine degree from the University of Maryland. He completed his internal medicine training at the George Washington University and completed his fellowship in pulmonary and critical care medicine at the University of Pennsylvania.