Abstract
OBJECTIVES: We examined the effect of Michigan's new school rules and vaccine coadministration on time to completion of all the school-required vaccine series, the individual adolescent vaccines newly required for sixth grade in 2010, and initiation of the human papillomavirus (HPV) vaccine series, which was recommended but not required for girls. METHODS: Data were derived from the Michigan Care Improvement Registry, a statewide Immunization Information System. We assessed the immunization status of Michigan children enrolled in sixth grade in 2009 or 2010. We used univariable and multivariable Cox regression models to identify significant associations between each factor and school completeness. RESULTS: Enrollment in sixth grade in 2010 and coadministration of adolescent vaccines at the first adolescent visit were significantly associated with completion of the vaccines required for Michigan's sixth graders. Children enrolled in sixth grade in 2010 had higher coverage with the newly required adolescent vaccines by age 13 years than did sixth graders in 2009, but there was little difference in the rate of HPV vaccine initiation among girls. CONCLUSIONS: Education and outreach efforts, particularly regarding the importance and benefits of coadministration of all recommended vaccines in adolescents, should be directed toward health care providers, parents, and adolescents.