Paul Offit is a pediatrician specializing in infectious diseases and an expert on vaccines, immunology, and virology. He is the co-inventor of a rotavirus vaccine that has been credited with saving hundreds of lives every day. Offit is the Maurice R. Hilleman professor of vaccinology, professor of pediatrics at the Perelman School of Medicine at the University of Pennsylvania and director of The Vaccine Education Center at Children's Hospital of Philadelphia (CHOP). Offit is currently a member of National Institutes of Health (NIH) working group on vaccines, a subgroup of the "Accelerating COVID-19 Therapeutic Interventions and Vaccines" (ACTIV) comprised of experts to combat COVID-19. He is also a member of the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC). Previously, he was a member of the Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices. Offit is a board member of Vaccinate Your Family and Autism Science Foundation. "Overkill" is his 11th book.