Romulus Breban is a physicist by training. He obtained his PhD in physics in 2003, from the University of Maryland, College Park, with a thesis in chaotic dynamical systems and fractals. Subsequently, he held two postdoctoral appointments where he specialized in the mathematical modeling of infectious diseases: first with Sally Blower at the University of California, Los Angeles, and second with Pejman Rohani at the University of Georgia. In 2008, he joined Institut Pasteur, Paris.