In early January 2026, the U.S. Centers for Disease Control and Prevention announced changes to the childhood immunization schedules, reducing the number of vaccines recommended for children. This change led to the U.S. being an outlier in terms of required vaccines for children. One reason people express concern about vaccines is fear of adverse reactions. It may surprise many that there is a comprehensive system in place to monitor adverse outcomes, and this is the topic of this episode with guest Dr. Jeffrey Morris.

Dr. Jeffrey Morris is the George S. Pepper Professor of Public Health and Preventative Medicine and Director Biostatistics Division, Department of Biostatistics, Epidemiology and Informatics at the Perelman School of Medicine University of Pennsylvania. He has been actively involved in scientific communication efforts on social media and with various media outlets. He is also a distinguished research fellow at the Annenberg Center for Public Policy.