Study Finds More Adolescent Vaccines Are Being Given at Ages 11 or 12

A new study found that the rate of adolescent vaccines being given at the ages of 11 and 12 years appears to be increasing; however, providers are not always administering all indicated vaccines during a vaccination visit. The findings from the population-based cross-sectional study were reported in the Archives of Pediatrics & Adolescent Medicine [2011;165(9):813-818]. By 2008, several new vaccine recommendations were made for adolescents in the United States. These recommendations included routine administration of the meningococcal conjugate vaccine (MCV4) and a booster dose of tetanus and diphtheria (Td) toxoids with acellular pertussis (Tdap) vaccine for all adolescents, in addition to the quadrivalent human papillomavirus (HPV) vaccine for females. Previous data surrounding adolescent vaccines has reported which vaccines teenagers have received during their lifetime; however, the data did not indicate specific ages when the vaccines were given. In this study, researchers determined the age of vaccination overall and by birth cohort for vaccines using data from the Centers for Disease Control and Prevention’s 2009 National Immunization Survey-Teen (NIS-Teen). The NIS-Teen used random digit dialing to survey households with adolescents 13 through 17 years of age. During the survey, they gained consent to contact vaccination providers for immunization records. The authors of the study examined immunization data for 3 vaccines recommended for infants and children (measles-containing, hepatitis B, and varicella) and 3 vaccines recommended at age 11 to 12 (Td/Tdap, meningococcal-containing and HPV). Participants were considered up-to-date on vaccinations if they had received ≥2 doses of measles-containing, ≥3 doses of hepatitis B (or 2 doses of Recombivax), ≥1 doses of Td/Tdap, ≥1 doses of meningococcal-containing, and, for females, ≥1 doses of HPV. The outcome measures of the study were being up-to-date with vaccinations at 3 ages: by 11 years to examine childhood vaccination efforts; by 13 years to examine vaccinations given at 11 and 12 years; and by the time of the interview (>13 years) to assess any catch-up vaccinations. The study’s authors found that for the 3 childhood immunizations, vaccination coverage by age 11 increased with each birth cohort. When researchers examined data for the Td/Tdap vaccine, they found that 6.1% of adolescents had received the vaccine by age 11; however, that figure increased by 42.1 percentage points by age 13. In addition, the percentage of individuals who received the vaccine at 11 to 12 years of age increased with each birth cohort. For example, in the 1991 cohort, 33.8% of participants received the vaccine at age 11 or 12 compared with 68.2% in the 1996 cohort (P<.001). By age 13, 18.6% of participants had received the meningococcal-containing vaccine. The study’s authors found that the percentage of adolescents who received the meningococcal-containing vaccine at age 11 or 12 increased significantly from the 1993 birth cohort, where 8.4% received the vaccine, compared with the 1996 birth cohort, where 50.0% received the vaccine (P<.001). Similarly, there was a significant increase in the percent of adolescent females who received the HPV vaccine at age 11 or 12 in the 1996 birth cohort (30.5%) compared with the 1994 cohort (11.1%, P<.001). Researchers found that 54.9% of adolescents had at least 1 vaccination visit at age 11 to 12 years, but providers did not always administer all recommended vaccinations. Of those who had a vaccination visit at 11 or 12 years of age, 19.5% did not receive Td/Tdap, 60.9% did not receive meningococcal-containing vaccine, and 62.4% did not receive the HPV vaccine. According to the study’s authors there were several limitations of the study. The telephone survey may have been affected by nonresponse or homes without landline telephones. Researchers also had to exclude adolescents who did not have adequate immunization data from a provider and all vaccination providers may not have been identified, which could have led to incomplete histories.