An Event History Analysis of Childhood Immunization: The Changing Tempo of MMR Vaccination in the United States

Laura Blakeslee, University of Wisconsin-Madison

Wakefield et al's (1998) Lancet article (falsely linking Measles-Mumps-Rubella vaccine with autism) sparked a culture of vaccine resistance: many parents delayed or refused vaccines leaving clusters of children susceptible to outbreaks of vaccine-preventable disease. Using data from the National Immunization Survey (1995-2011), this study examines: the age at which a "critical proportion" (10%) of children had not yet received the MMR vaccine; and how age at vaccination varied over time and by child, mother, and household characteristic. Preliminary results show: children generally were vaccinated at younger ages over time, but recent years saw an increase of 3.5 months in the age when 10% of children were still unvaccinated against MMR; and older ages at vaccination were associated with boys, Whites, children of less educated, unmarried mothers, and children living in larger households in the western US. Immunization programs and policies should address this delay to reduce community susceptibility to disease.