Defining a composite adolescent immunization coverage metric

Unlike childhood immunization coverage, the National Immunization Survey doesn’t release a composite adolescent immunization rate. When immunization-adolescents was introduced in the 2013 Edition of America’s Health Rankings (AHR), a composite rate was calculated by averaging the percentage of adolescents aged 13 to 17 years who received 1 dose of tetanus, diphtheria, and acellular pertussis (Tdap) vaccine since the age of 10 years, 1 dose of meningococcal conjugate vaccine (MenACWY), and females who received 3 doses of human papillomavirus (HPV) vaccine. However, this method of combining immunization rates misrepresents the percentage of teens who are fully vaccinated because HPV immunization coverage rates are much lower than Tdap coverage rates.

Using 2014 AHR data, we modeled two new definitions of adolescent immunization coverage and compared the results to the 2014 AHR model: 1) HPV immunization rate as an indicator of full adolescent vaccination; and 2) distribute the weight of immunization-adolescents (2.5%) equally between Tdap, MenACWY, and HPV vaccine rates.

In scenario 1, 35 states remained unchanged, 10 states moved ±1 ranks, 3 states moved +2 ranks,  1 state moved -3, and 1 moved -4 ranks. In scenario 2, 34 states remained unchanged, 11 states moved ±1, 2 moved ±2, and 3 states moved ±3 ranks.

Many adolescents are not receiving the HPV vaccine when they receive other recommended vaccines. Replacing the current AHR adolescent immunization coverage metric with either of the above tested scenarios will better illustrate immunization coverage by state among adolescents and bring attention to low HPV vaccination rates.