Direct and Spillover Effects of Middle School Vaccination Requirements

We study the direct and spillover effects of state requirements that middle school youths obtain a tetanus, diphtheria, and pertussis (Tdap) booster prior to middle school entry. These mandates significantly increased Tdap vaccine take-up and reduced pertussis (whooping cough) incidence by about 32 percent. We also document cross-vaccine spillovers: the mandates significantly increased adolescent vaccination rates for meningococcal disease and human papillomavirus (HPV)—which is responsible for 98 percent of cervical cancers—by 8–34 percent, with particularly large effects for children from low SES households. We find important roles for both parents and providers in generating these spillovers.