Direct and Spillover Effects of Middle School Vaccination Requirements

Abstract

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 increased vaccine take-up by 29 percent and reduced pertussis (whooping cough) incidence in the population by a much larger 53 percent due to herd immunity effects. We also document cross-vaccine spillovers: the mandates increased adolescent vaccination for meningococcal disease and human papillomavirus (which is responsible for 98 percent of cervical cancers) by 8-34 percent, with particularly large effects for children from low SES households.