Vaccine hesitancy, defined as reluctance or refusal to have oneself or one's children vaccinated against infectious diseases, is certainly not a modern novelty. In recent years, however, the idea has inspired the emergence of socio-political groups and organizations that make up what is now referred to as the “anti-vax” movement. Once a fringe outlier in the public health sphere, the anti-vax movement has slowly, but surely crept its way into mainstream politics. Although today’s anti-vaccine sentiments are largely politically-motivated, the growing opposition to vaccines has now begun to exhibit real world consequences. But how and when did it all begin? And what could lower vaccination rates in the US mean for the future of public health? This week, we investigate vaccine hesitancy with Drs. Karin Byers, MD, MS, Clinical Director for the Division of Infectious Diseases, and Sahil Angelo, MD, a current ID fellow at UPMC. Join us as we explore the history of vaccine opposition, consider how the COVID-19 pandemic influenced vaccine hesitancy, and examine the current state of the anti-vax movement.