National, Regional, State, and Selected Local Area Vaccination Coverage Among Adolescents Aged 13–17 Years — United States, 2014

Routine immunization is recommended for adolescents aged 11-12 years by the Advisory Committee on Immunization Practices (ACIP) for protection against diseases including pertussis, meningococcal disease, and human papillomavirus (HPV)-associated cancers. To assess vaccination coverage among adolescents, CDC analyzed data collected regarding 20,827 adolescents through the 2014 National Immunization Survey-Teen (NIS-Teen). From 2013 to 2014, coverage among adolescents aged 13-17 years increased for all routinely recommended vaccines: from 84.7% to 87.6% for ≥1 tetanus-diphtheria-acellular pertussis (Tdap) vaccine dose, from 76.6% to 79.3% for ≥1 meningococcal conjugate (MenACWY) vaccine dose, from 56.7% to 60.0% and from 33.6% to 41.7% for ≥1 HPV vaccine dose among females and males, respectively.† Coverage differed by state and local area. Despite overall progress in vaccination coverage among adolescents, HPV vaccination coverage continues to lag behind Tdap and MenACWY coverage at state and national levels. Seven public health jurisdictions achieved significant increases in ≥1- or ≥3-dose HPV vaccination coverage among females in 2014, demonstrating that substantial improvement in HPV vaccination coverage is feasible.

Revised methods for defining adequate provider data were implemented in 2014 and were retrospectively applied to 2013 NIS-Teen data for purposes of comparing these two most recent survey years. As a result, revised 2013 coverage estimates presented in this report differ from those previously published, and 2014 and revised 2013 NIS-Teen coverage estimates are not directly comparable to those published for the 2006-2013 survey years. This definition change will decrease some vaccination coverage estimates, particularly for some states and local areas. Details regarding this methodologic change and the assessment of its impact on vaccination coverage estimates are described elsewhere. † For all vaccines included in this report, t-tests were used to assess vaccination coverage differences by survey year (2014 compared with 2013), age, sex, race/ethnicity, and poverty status. Differences were considered statistically significant at p<0.05.

Vaccination Coverage by Selected Characteristics
In 2014, HPV coverage and series completion were higher among older females compared with females aged 13 years; these findings were observed less consistently among males (Table 1). Vaccination coverage with each HPV dose and HPV series completion § § were higher among females than males (Table 1). No significant differences were observed in Tdap or MenACWY vaccination coverage by sex.
Coverage estimates for each HPV dose and for ≥1 MenACWY were higher among Hispanic adolescents compared with non-Hispanic white adolescents, and estimates for each HPV dose were higher among adolescents living below the poverty level compared with those at or above the poverty level ¶ ¶ ( Table 2). Coverage with ≥1 HPV dose was higher among non-Hispanic black and American Indian/Alaska Native adolescents compared with non-Hispanic white adolescents. Similar to 2013, non-Hispanic black female adolescents had lower HPV series completion compared with non-Hispanic white female adolescents (3). Adolescents living below the poverty level had lower ≥1 Tdap coverage than adolescents living at or above the poverty level.

State Vaccination Coverage
In 2014, vaccination coverage varied among the 50 states and DC ( North Carolina); percentage point increases ranged from 14.5 (Georgia) to 28.6 (DC). One state (Tennessee) experienced a decrease (16.0 percentage points) in ≥3-dose HPV coverage among females.

Discussion
From 2013 to 2014, vaccination coverage among adolescents aged 13-17 years increased for all vaccines routinely recommended for adolescents. Achieving high HPV vaccination coverage in early adolescence is important to optimize protection before HPV exposure. In 2014, the President's Cancer Panel Report called for coordinated efforts to improve HPV vaccination coverage, including reducing missed opportunities to recommend and administer § § The completion rate for 3-dose HPV vaccination series represents the percentage of adolescents who received ≥3 doses among those who had ≥1 HPV vaccine dose and ≥24 weeks between the first dose and the interview date. ¶ ¶ Adolescents were classified as below federal poverty level if their total family income was less than the federal poverty level specified for the applicable family size and number of children aged <18 years. All others were classified as at or above the poverty level. Poverty status was unknown for 714 adolescents. Additional information available at http://www.census.gov/hhes/ www/poverty/data/threshld/index.html. HPV vaccine at every clinical opportunity, increasing parents' and adolescents' acceptance of HPV vaccine, and maximizing access to HPV vaccination services (4). After experiencing no progress in national HPV vaccination coverage among females aged 13-17 years from 2011 to 2012, coverage increased modestly in 2013, and an additional 3.3 percentage points in 2014 (3,5). Five states, DC, and one local area experienced large, significant increases in ≥1-or ≥3-dose HPV vaccination coverage among females, including four (Chicago, DC, Georgia, and Utah) of the 11 jurisdictions that received resources in 2013 through the Prevention and Public Health Fund from CDC to conduct activities to improve HPV vaccination coverage (6).
In six of the seven jurisdictions with increases in ≥1-or ≥3-dose HPV coverage among females, combinations of strategies were important. Immunization programs highlighted incorporating HPV vaccination in cancer control plans, joint initiatives with cancer prevention and immunization stakeholders, public communication campaigns, immunization information system-based reminder/recall, assessment and feedback  A revised adequate provider data definition was implemented in 2014 NIS-Teen, and estimates might not be directly comparable to those previously published. For comparative purposes, 2013 estimates included in this table have been calculated by retrospectively applying the revised adequate provider data definition to 2013 NIS-Teen data and, as a result, will differ from those previously published. § Includes percentages receiving Tdap at or after age 10 years. ¶ Statistically significant difference (p<0.05) compared with 2013 NIS-Teen estimates. ** Includes percentages receiving MenACWY or meningococcal-unknown type vaccine. † † ≥2 doses of MenACWY or meningococcal-unknown type vaccine. Calculated only among adolescents who were aged 17 years at time of interview. Does not include adolescents who received 1 dose of MenACWY vaccine at or after age 16 years. § § HPV vaccine, either quadrivalent (4vHPV) or bivalent (2vHPV). Although only 4vHPV was recommended for use in males in 2014, some might have received 2vHPV.
In 2014 data, percentage was reported among 10,084 females and 10,743 males. In 2013 data, percentage was reported among 9,042 females and 9,906 males. Some adolescents might have received more than the 3 recommended HPV vaccine doses. ¶ ¶ Statistically significant difference (p<0.05) in estimated vaccination coverage by age; reference group was adolescents aged 13 years. *** The completion rate for the 3-dose HPV vaccination series represents the percentage of adolescents who received ≥3 HPV doses among those who had ≥1 HPV vaccine dose with at least 24 weeks between the first dose and the interview date. The denominator for this calculation was limited to 5,703 females and 3,935 males in 2014 and 4,704 females and 2,623 males in 2013 who received their first HPV dose and had enough time to receive the third HPV dose. † † † By parent/guardian report or provider records.
activities (including clinician-to-clinician educational sessions emphasizing providing strong vaccination recommendations at ages 11-12 years), practice-focused strategies to educate staff and provide input on how to improve routine HPV vaccination within the practice, and using all opportunities to educate clinicians and parents about the importance of on-time HPV vaccination. These experiences are informing development of best practices for improving HPV vaccination coverage. At the start of 2014, only two jurisdictions had school requirements for HPV vaccination, both with broad exemption provisions (http://www.immunize.org/laws). In late 2014, DC expanded its existing school requirement for HPV vaccination to include males and females through 12th grade, with a requirement for submitting exemption forms annually (http://www.dcregs. dc.gov/Gateway/NoticeHome.aspx?NoticeID=5225019).
Some providers delay strongly recommending HPV vaccine until older adolescence (7). A comparison of age-specific HPV vaccination coverage estimates from 2013 and 2014 showed no improvement in coverage among females aged 13 years, although coverage among males aged 13 years did increase by 6.5 percentage points. Clinician resources to facilitate age-appropriate recommendation and administration of HPV vaccine are available at http://www.cdc.gov/vaccines/ who/teens/for-hcp/hpv-resources.html. Changes in clinical practice, health systems, and parental acceptance take time.
Because NIS-Teen monitors coverage among adolescents aged 13-17 years, the impact of interventions aimed at increasing HPV vaccine administration to adolescents aged 11-12 years cannot be measured until 1-2 years after implementation. Estimated coverage with ≥1 MenACWY dose continues to increase among adolescents, but geographic disparities are evident and vaccination coverage estimates are still lower than for Tdap. Although 78.8% of adolescents aged 17 years received ≥1 dose of MenACWY, only 28.5% received the complete the 2-dose series. Further evaluation might identify factors that could lead to improved MenACWY series coverage, although older adolescents have fewer preventive health visits, and awareness of the 2-dose recommendation (http://www.cdc. gov/mmwr/preview/mmwrhtml/mm6003a3.htm) might still be low. In addition, because NIS-Teen includes adolescents aged 13-17 years, receipt of MenACWY at age ≥18 years is not captured in these coverage estimates. † Adolescent's race/ethnicity was reported by their parent or guardian. Adolescents identified in this report as white, black, Asian, American Indian/Alaska Native, or multiracial were reported by the parent or guardian as non-Hispanic. Adolescents identified as multiracial had more than one race category selected. Adolescents identified as Hispanic might be of any race. Native Hawaiian or other Pacific Islanders were not included in the table because of small sample sizes. § Adolescents were classified as below poverty level if their total family income was less than the federal poverty level specified for the applicable family size and number of children aged <18 years. All others were classified as at or above the poverty level. Additional information available at http://www.census.gov/hhes/ www/poverty/data/threshld/index.html. Poverty status was unknown for 714 adolescents. ¶ Estimates with 95% CI half-widths >10 might not be reliable. ** Includes percentages receiving Tdap at or after age 10 years. † † Statistically significant difference (p<0.05) in estimated vaccination coverage by race/ethnicity or poverty level; referent groups were white, non-Hispanic adolescents, and adolescents living at or above poverty level, respectively. § § Includes percentages receiving MenACWY and meningococcal-unknown type vaccine. ¶ ¶ HPV vaccine, either quadrivalent (4vHPV) or bivalent (2vHPV). Although only 4vHPV was recommended for use in males in 2014, some males might have received 2vHPV. Percentage was reported among 10,084 females and 10,743 males. Some adolescents might have received more than the 3 recommended HPV vaccine doses. *** The completion rate for the 3-dose HPV vaccination series represents the percentage of adolescents who received 3 HPV doses among those who had ≥1 HPV vaccine dose with at least 24 weeks between the first dose and the interview date. The denominator for this calculation was limited to 5,703 females and 3,935 males who received their first HPV dose and had enough time to receive the third HPV dose. † † † By parent/guardian report or provider records. MMR vaccine is routinely recommended at ages 12-15 months and 4-6 years (1), and although ≥2-dose MMR coverage among adolescents remains high nationally, seven states had coverage <90%,*** suggesting important vulnerability to measles outbreaks. As of July 24, 2015, a total of 183 measles cases have been reported this year in the United States (http://www.cdc. gov/measles/cases-outbreaks.html). High MMR coverage is needed to sustain elimination and protect those who cannot be directly vaccinated. Health care providers of adolescents should assess their patients' vaccination status at each clinical opportunity, take advantage of immunization information systems, which should reflect vaccines delivered in any setting, and offer all vaccines for which adolescents are eligible, including missing doses of MMR, varicella, and hepatitis B vaccines.  The findings in this report are subject to at least three limitations. First, household response rates for landline and cell phone samples were 60.3% and 31.2%, respectively, and only 57.1% of landline-completed interviews and 52.3% of cell phone-completed interviews had adequate provider data. Second, estimates might be biased even after adjustments for nonresponse and phoneless households. A total survey error model of 2011 NIS-Teen that included comparison with provider-reported data from National Health Interview Survey participants indicated coverage estimates were 1.3-6.7 percentage points higher as a result of noncoverage and household nonresponse error. † † † Weights have been adjusted to account for the increasing prevalence of cell phone-only households over time. Nonresponse bias might change, which could affect comparisons of estimates across survey years. Finally, estimates stratified by state/local area and race/ethnicity might be unreliable because of small sample sizes.

TABLE 3. Estimated vaccination coverage with selected vaccines and doses* among adolescents aged 13-17 years, † by HHS region and state or selected local areas -National Immunization Survey-Teen (NIS-Teen), United
National HPV vaccination coverage estimates continue to be low for adolescents, despite similar percentage point increases in coverage in 2014 for ≥1 Tdap dose, ≥1 MenACWY dose, and, among females, ≥1 HPV dose. Differences in coverage estimates by vaccine indicate many missed opportunities for simultaneous administration of HPV with Tdap or MenACWY. Wide state and local variation in adolescent coverage with routinely recommended vaccines persists. Routinely recommending HPV vaccination at ages 11-12 years during the same visit and with the same emphasis used for other vaccines is critical. Resources are available for clinicians that focus on cancer prevention and ways to confidently address questions regarding HPV vaccine safety and efficacy. Multifaceted interventions that engage clinicians and other immunization stakeholders and increase community awareness might improve HPV vaccination coverage (8). Recent licensure of two vaccines for adolescents (nine-valent HPV [9vHPV] and serogroup B meningococcal vaccines) might provide opportunities for additional protection of adolescents  against vaccine-preventable diseases in the years ahead (2,9). Furthermore, clinical trials are ongoing to evaluate alternative dosing schedules for 9vHPV, which will be reviewed by ACIP in consideration of reduced-dose HPV vaccination schedules in the United States (2). To protect against HPV-associated cancers and other vaccine-preventable diseases, clinicians should ensure that adolescents receive all vaccines currently recommended routinely at ages 11-12 years. 1 Immunization Services Division, National Center for Immunization and Respiratory Diseases, CDC; 2 Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, CDC; 3 Division of Sexually Transmitted Diseases, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC.

Summary
What is already known on this topic?
Routine immunization is recommended for adolescents aged 11-12 years by the Advisory Committee on Immunization Practices for protection against diseases including pertussis, meningococcal disease, and human papillomavirus (HPV)-associated cancers.