Using the North Dakota Immunization Information System (NDIIS) to Determine Adolescent Vaccination Rates and Uptake

Since 2005, three new vaccines have been recommended for use in adolescents between 11 and 12 years of age. Meningococcal conjugate vaccine (MCV4) and a tetanus, diphtheria and pertussis vaccine (Tdap) for adolescents and adults were licensed in 2005, and a human papillomavirus vaccine (HPV4) was licensed in 2006. A majority of providers use NDIIS to obtain information about patients' immunization histories. NDIIS allows in-depth and timely analysis of vaccine uptake in North Dakota. The number of doses administered for each vaccine was charted monthly and the percent up-to-date was analyzed for adolescents 13-17 years of age, the age range included in the National Immunization Survey. The percent of adolescents 11-12 years of age, the recommended age range, was analyzed for missed vaccine opportunities. Among adolescents 11-12 years of age who received Tdap, 76.4% received MCV4 on the same day. Of females 11-12 years of age who received Tdap, 31.6% received a dose of HPV4 on the same day. Of adolescents 13-17 years of age, 60.6% are up-to-date for Tdap, 55% are up-to-date for MCV4. Only 41% of females have initiated the three dose HPV4 series. From licensure until late 2007 there was a steady uptake of adolescent vaccines. Since late 2007 the number of doses administered for each vaccine has reached a plateau and the number of doses of MCV4 administered per month went down even though the majority of recommended adolescents are not up-to-date. Further education needs to target the majority of adolescents not vaccinated and their parents.