Improving adolescent human papillomavirus (HPV) immunization uptake in school-based health centers through awareness campaigns

Abstract

Purpose:

The aim of this study was to measure the effect of a multicomponent human papillomavirus (HPV) vaccine promotion campaign on adolescent HPV vaccine uptake at school-based health centers (SBHCs) in Seattle, WA.

Methods:

Youth-led HPV vaccine promotion campaigns were introduced in 2016 in 13 schools with SBHCs in Seattle. Five other schools with SBHCs served as controls. Vaccination records for students were obtained from the Washington Immunization Information System from September 2012 to August 2018. We compared increase in HPV vaccine uptake in SBHCs between 1) intervention and control schools, and 2) pre- and post-intervention periods in intervention schools using generalized estimating equations.

Results:

HPV vaccine uptake was high at baseline among students that use SBHCs for vaccines and has steadily increased between 2012 and 2018. Implementing the promotion campaign resulted in 14% higher (95% Confidence Interval (CI): 1%, 30%) HPV vaccine uptake in intervention SBHCs compared to control SBHCs, adjusting for time and confounders. Comparing pre-and post-intervention periods in intervention SBHCs, HPV vaccine uptake was 14% higher (95% CI: −4%, 35%) in the post-intervention period. SBHCs that received more active intervention activities saw 9% higher (95% CI: 1%, 21%) vaccine uptake compared to those that received passive intervention.

Conclusion:

The vaccination promotion program implemented in a school-based setting resulted in higher HPV vaccine uptake in the post-intervention period compared to pre-intervention period, but this increase was not statistically significant. Even so, schools that received more intervention activities for longer periods of time had higher HPV vaccine uptake.

Introduction

The human papillomavirus (HPV) vaccine is very effective in preventing HPV infections among all genders and in reducing the occurrence of anogenital warts and cervical cancer [1–6]. National guidelines recommend HPV vaccine for routine use among 11-to-12-year-olds [7]. Despite the benefits, HPV vaccination rates in the US remain low. The Healthy People 2020 target for HPV vaccine coverage with 2 or 3 doses in 13–15-year olds in the US is 80% [8]. As of 2017, only 39% of the adolescents were up-to-date (UTD) for the vaccine series. In Washington, HPV vaccine coverage among adolescents aged 13–17 years is marginally better, with 72% of teens receiving the first dose and 55% UTD with the vaccine series [9].

The Community Preventive Services Task Force, which is a panel of public health and prevention experts with policy expertise in community preventive services and health promotion set up by the U.S. Department of Health and Human Services, recommends school-located vaccination programs based on strong evidence of effectiveness in increasing vaccination rates [10,11]. Government-funded school-based vaccination programs have led to high HPV vaccination rates in Australia [12], the United Kingdom [13], Canada [14,15], and Malaysia [16]. As HPV vaccine is recommended for school-age children, offering the vaccine in school-based health centers (SBHCs) can be an effective way to reach the target population, especially uninsured and children from low-income families [17,18]. Schools provide a convenient place for adolescents to receive immunizations and can help overcome barriers such as traveling to healthcare clinics and related administrative costs. Studies show that parents favor vaccinating their children at SBHCs for HPV, especially when it is offered alongside other adolescent vaccines such as the annual Influenza vaccine or the Tetanus-Diphtheria-Pertussis (TDaP) booster [18,19]. Moreover, HPV vaccines are offered at no or low cost in Seattle SBHCs through the Vaccines for Children (VFC) program [20]. Although SBHCs have been instrumental in improving vaccination rates in adolescents, financial reimbursements for vaccines administered in schools, parental concerns about qualifications of personnel administering the vaccines, lack of effective and timely communication about school vaccination programs to parents, inefficient consent processes, and ability of school administrators to prioritize and implement vaccination programs could be barriers to their success [19,21].

SBHCs in King County are funded by the Families, Education, Preschool, and Promise Levy, the Best Starts for Kids Levy, and King County General Funds, with services coordinated by Public Health – Seattle & King County (PHSKC). SBHCs offer immunizations, reproductive healthcare, nutrition education, mental health counseling, and other services to approximately 10,000 children in elementary, middle, and high schools. There are currently 33 SBHCs in King County operated by healthcare sponsor agencies [22]. Recognizing the importance of increasing access to HPV vaccine in settings where adolescents receive health care, in 2015, PHSKC partnered with SBHCs at middle and high schools in Seattle Public Schools to pilot new strategies for increasing HPV vaccine awareness and uptake. A key strategy of the intervention was to launch youth-led campaigns to create awareness about HPV vaccine and promote connections to SBHCs. This study evaluates the effect of this multicomponent intervention on vaccine uptake in 13 SBHCs in Seattle Public Schools.

Methods

PHSKC staff approached school authorities and SBHC staff from four middle schools and nine high schools in Seattle to garner support for this project. A convenience sample of five high schools that were not contacted for this study but routinely reported immunizations to the Washington State Immunization Information System (WA-IIS) served as controls. Students from all participating schools could choose to receive HPV vaccines at sites other than SBHCs, such as their primary care provider. This study was approved by the Washington State Institutional Review Board.

Intervention

In high schools, a key component of the intervention was recruitment of “student champions” who designed and led HPV vaccine promotion campaign activities such as raffles, trivia, movie nights, class presentations, and overhead announcements. Student champions were recruited through classroom presentations, outreach to teachers and school counselors, and word-of-mouth between students. School champions were educated on HPV vaccines, harmful impacts of HPV infections, and their SBHCs. Messaging and education were tailored to the environmental and socio-economical culture, climate, and demographics unique to the school. School champion involvement varied by school, with some champions being involved for the entire duration of the intervention. Champions worked with certified and experienced health educators and public health nurses from PHSKC and SBHC staff to develop educational material. Other campaign activities included hosting themed HPV vaccine promotion weeks, informational tabling events in lunchrooms and other high traffic areas on campus, and outreach events where SBHC staff offered free immunization status checks through the Washington State Immunization Information System (WA-IIS). Outreach to parents involved presentations about SBHC services and HPV vaccine at Parent-Teacher-Student Association (PTSA) meetings, posting related information on school blogs and newsletters, and hosting information booths at school events. The development of the intervention was guided by the Theory of Planned Behavior [23], the Health Belief Model [24], and previously published studies [25,26].

Successful implementation of the intervention depended heavily on the commitment shown by student champions and school authorities. This resulted in some schools receiving more intensive campaign activities than others. For example, campaigns in middle schools had fewer campaign activities compared to high schools, were largely focused on parent outreach, and were developed and led by PHSKC health educators and SBHC staff rather than student champions.

Intervention activities were considered “active” if they involved face-to-face engagement with parents and/or students, and “passive” if they involved indirect engagement such as information disseminated via posters and newsletters. Active interventions were scored higher. As parents’ permission is generally required for school-based vaccinations for minors, active interventions aimed at parents were assumed to be most impactful. Each activity was scored as follows: passive student outreach=1, passive parent outreach=2, active student outreach=3, and active parent outreach=4. The intervention score for each school was the sum total of activity scores for the years they received the intervention. Based on the distribution of scores, a cut-off level of 10 was chosen. A school was categorized as receiving “low intensity intervention” if the intervention score was ≤10 and “high intensity intervention” if the score was >10. Six out of thirteen intervention schools had scores of ≤10. Scores ranged from 5 to 15 for middle schools and 3 to 70 for high schools. Implementation of the intervention was more successful in high schools due to student champion involvement. Details of campaign activities and scoring are in Appendix Table 1.

Intervention Period

Interventions did not start at the same time for all schools. Five of nine high schools and one of four middle schools began intervention in the 2015–16 school year. The program was expanded to include all 13 participating schools in school year 2016–17. The pre-intervention period for this study started on September 1, 2012 for all schools and ended on the last day of the summer term before the intervention began. For example, if the intervention began in a school during the 2015–16 school year (start date of September 1, 2015), their pre-intervention period ended on August 31, 2015 and post-intervention period began on September 1, 2015.

Data Collection

Student vaccine records were obtained from WA-IIS. Vaccines administered at SBHCs are transmitted electronically to WA-IIS via an interface between the SBHCs’ electronic medical record system and WA-IIS. We extracted immunization data from WA-IIS for King County residents born between January 1, 1997, and June 30, 2017, which includes children aged 11 to 18 years old. These data include registry participants’ birth date, sex, and vaccine information such as vaccine formulation, date of vaccination, validity of the dose, and the provider and facility administering the vaccine. WA-IIS flags a vaccine dose as “invalid” if it was administered earlier than the recommended age, was given at an improper interval for the series, was not licensed for use in the US, or was marked as compromised. If a provider indicates that a registry participant died or has moved or gone elsewhere then their record is marked as “inactive”[27]. Invalid vaccine doses and inactive participants were excluded from the analysis. Four records with data entry errors (invalid birth date, duplicate records) were also excluded. Age at HPV vaccine initiation and completion, and intervals between HPV doses were determined for each participant. We also identified whether the patient received an HPV dose at the SBHC or at another clinic. The data were aggregated and analyzed at the school level.

In December 2016, the Advisory Committee of Immunization Practices (ACIP) updated HPV vaccine recommendations from a 3-dose series to a 2-dose series [7]. This recommendation went into effect during our intervention period and guided our final analysis. According to the updated recommendation, children who initiated the vaccine series before age 15 years, should receive a 2-dose series with 6 months between doses 1 and 2. A 3-dose series is recommended if vaccine series is initiated after age 15 years, with an interval of 28 days between doses 1 and 2 and 6 months between doses 1 and 3. Age at series initiation was used to determine the number of doses required for each participant to become UTD for the HPV vaccine series in our study.

Previous studies suggest that school/clinic enrollment, gender, race and/or ethnicity, and family income and education are associated with in HPV vaccination uptake in adolescents [19,28,29]. Based on this evidence, we collected data for school-level demographic factors such as student enrollment, proportion of male students, proportion of Caucasian students, proportion of students eligible for free or reduced-price meal program, and proportion of students eligible for the Individual Education Program (IEP) from the Washington Office of Superintendent of Public Instruction website [30].

Outcome Measures

A student is defined as an “SBHC user” for a given school if they received at least one vaccine dose for any vaccine at that SBHC over the study period, based on records in WA-IIS.

Eligibility for HPV vaccine was calculated by subtracting the number of students who were already complete for the HPV vaccine series from the total SBHC users as defined above. Three outcomes were assessed in this analysis:

• HPV vaccine uptake: Proportion of SBHC users who received ≥1 doses of HPV vaccine at the SBHC when they were eligible for an HPV dose. This outcome measures the direct impact of the intervention on HPV vaccine uptake at each SBHC.

• HPV series initiation: Proportion of SBHC users who received ≥1 dose of HPV vaccine at the SBHC or another clinic.

• HPV series completion: proportion of SBHC users who completed their HPV vaccine series at the SBHC or at another clinic.

All outcomes were measured annually for school years from 2012–13 to 2017–18.

Statistical Analysis

We described temporal trends in HPV vaccine doses for middle and high intervention schools by gender and plotted vaccine uptake over time for each school to describe within-school secular trends. Generalized estimating equation (GEE) method was used to estimate the population-averaged effect of the intervention [31]. Longitudinal correlation between SBHCs was specified using an exchangeable correlation matrix, i.e., correlation between observations collected for the same SBHC are assumed to be constant. Variance of intervention effect was estimated using robust variance estimators. See Appendix for model details. Models were implemented within the ‘geepack’ package in R version 3.4 [32,33]. SAS version 9.4 [34] was used for data cleaning and management.

To assess the effect of intervention on vaccine uptake, we compared:

1. Mean vaccine uptake between intervention and control SBHCs. This approach ensures that we utilize all the data available to us from both intervention and control schools.

2. Mean vaccine uptake between pre-intervention and post-intervention periods in intervention SBHCs. As we matched on the study unit, there is low risk of confounding, but we lose information by excluding data on control SBHCs.

3. Mean vaccine uptake between SBHCs in schools that received high intensity of intervention to those that received low intensity of intervention to test whether number and type of campaign activities affected vaccine uptake. This was an ad hoc analysis.

All models were adjusted for time and demographic factors that differed between schools such as student enrollment, proportion of male students, proportion of Caucasian students, and proportion of students eligible for free or reduced-price meal program.

Results

The study includes 5,559 adolescents aged 11–18 years who visited at least one of the 18 SBHCs for any vaccination (SBHC users) between September 1, 2012 and August 31, 2018. Of them, 3,328 (60%) received at least one dose of HPV vaccine at SBHCs. Five thousand and ninety-seven (91%) adolescents received at least one dose of HPV vaccine either at an SBHC or at a health care provider’s office. Out of 5,559 SBHC users, 4,095 (71%) completed the HPV vaccine series. A total of 17,548 vaccine-related visits were made to the 18 SBHCs between September 1, 2012 and August 31, 2018 (3.2 vaccine visits per child), of which 5,503 (31%) were for HPV vaccines.

Services received at SBHCs are complementary to services received in community settings and medical homes. To measure any increase in medical visits to SBHCs that may be driven by the intervention, we used data on student visits to SBHCs collected at school-level by PHSKC from SBHC sponsor agencies. Over the study period, 32% of students enrolled in participating schools used SBHCs for any medical reason (range at SBHC level: 10%−65%). Trend in the proportion of students enrolled in schools who used SBHCs for medical visits was consistent over time.

Figure 1 and Appendix table 1 describe the number of HPV vaccine doses received by gender among SBHC users from 2012–13 to 2017–18. Pattern of SBHC use by gender for HPV vaccines was different for middle and high schools. Half of the students that visited SBHCs for HPV vaccines in middle schools were males, compared to a third in high schools. This pattern was consistent over time. Uptake of doses 1 and 2 for both genders increased over time in middle and high schools. In high schools, uptake of dose 3 increased from 28% in 2012 to 58% in 2018 among males and from 53% to 67% among females. However in middle schools, dose 3 uptake dropped after 2015–16 which is likely due to change in recommendation to a 2-dose series for adolescents starting the series before 15 years of age. We did not see this trend in high schools likely because these were catch-up doses given to older adolescents in high schools. Overall, we saw a steady increase in uptake of HPV vaccine doses in SBHCs since before the start of intervention in 2015–16 school year.

Trends in HPV vaccine uptake for intervention schools by dose number and gender.

Trends in uptake of HPV vaccine doses for intervention high schools and middle schools in the left and right panels of the graph, respectively. Dose 1 is shown in red, dose 2 in green, and dose 3 in blue. Solid lines indicate vaccine uptake trends for females and dotted lines for males. Lines indicate trends in vaccination rates over time. HPV vaccine uptake for dose 3 decreases in the 2016–17 and 2017–18 school years after changes in vaccine recommendations from a 3-dose series to a 2-dose series in 2016.

Age of initiation and completion decreased for both genders in middle schools from 2012–13 to 2017–18 (Appendix table 1). Similar trend was observed in high school, except that there was no change in age of initiation for females. In the school year 2017–18, average age of HPV vaccine series initiation and completion was lower for females in both middle and high schools.

Figure 2 displays the temporal trends of HPV vaccine uptake, initiation, and completion for participating intervention and control SBHCs. Again, we see a general upward trend in HPV vaccine coverage over time among SBHCs from both groups. Baseline values of vaccine coverage are lower in control SBHCs and slopes of trendlines also appear to differ by school.

Trends in HPV vaccine uptake, initiation, and completion in participating school-based health centers.

Temporal trends in HPV vaccine uptake, initiation, and completion rates for participating school-based health centers. Panels in each row correspond to HPV vaccine uptake, initiation, and, completion respectively. Control schools are shown in red, intervention schools in blue. Absolute measures of HPV vaccination rate for individual schools in control or intervention group are indicated with dots to display between-school variability in each year. Lines indicate trends in vaccination rates over time. Each trend line corresponds to a SBHC. Vaccination rates in some control SBHCs are based on small numbers because few students visited SBHCs for vaccines in these schools.

Intervention schools had a greater number of students enrolled, higher proportion of Caucasian students (42.9% vs. 12.7%) and lower proportion of students eligible for free or reduced-price school meal program (37.9% vs. 60.1%) (Table 1). We adjusted the GEE models for these factors to make the comparison groups more similar. HPV vaccine uptake and completion rates in intervention schools were approximately 30 percentage points higher compared to control schools at the start of study period in 2012–13.

Table 1:

Demographic characteristics of intervention^* and control^‡ schools

Characteristics	Intervention Schools (N=13)	Control Schools (N=5)
Enrollment, N (range)	1158 (671–1715)	523 (203–1308)
% students who are male	50.7	55.5
% students who are Caucasian	42.9	12.7
% of students eligible for free or reduced-price meals	37.9	60.1
% students eligible for the Individualized Education Program	11.6	11.6
Baseline vaccine uptake† (%)	70.7	40.3
Baseline vaccine completion (%)	58.1	28.3

^*Intervention schools: Ballard High School, Garfield High School, Nathan Hale High School, Neighborcare Denny Middle School, Neighborcare Madison Middle School, Neighborcare Mercer Middle School, Neighborcare Roosevelt High School, Neighborcare Sealth High School, Neighborcare West Seattle High School, PHSKC - Ingraham High School, PHSKC- Cleveland High School, PHSKC- Rainier Beach High School, Washington Middle School

^‡Control schools: Franklin High School, Evergreen High School, Tyee High School, ICHS Seattle World School, Kent Phoenix Academy

^†:Baseline vaccine uptake and completion rates are for year 2012–2013

Mean HPV vaccine uptake was 14% higher (95% CI: 1%, 30%) in intervention SBHCs compared to control SBHCs, after adjusting for time and school-level factors (Table 2). Mean HPV vaccine initiation rate was 11% higher (95% CI: 1%, 22%) and mean completion rate was 33% higher (95% CI: 16%, 42%) in intervention SBHCs compared to control SBHCs. Although estimates are statistically significant, there is a possibility of residual confounding because we do not have information on some important confounders such as HPV vaccine knowledge and awareness among parents, parents’ education, and access to health clinics other than SBHCs [35].

Table 2:

Results of GEE models for effect of intervention on HPV vaccine uptake, initiation, and completion

	Outcomes
	HPV vaccine uptake aRR (95% CI)	P-value	HPV vaccine initiation aRR (95%CI)	P-value	HPV vaccine completion aRR (95%CI)	P-value
Model 1
Intervention vs. Control
Group: Intervention	1.14 (1.01, 1.30)	0.03	1.11 (1.01, 1.22)	0.02	1.33 (1.16, 1.42)	<0.001
Model 2
Pre-intervention period vs. Post-intervention period
Group: Post-intervention	1.14 (0.96, 1.35)	0.14	1.04 (0.94, 1.14)	0.5	0.91 (0.81, 1.03)	0.13
Model 3
High intensity intervention vs. low intensity intervention†
Group: High intensity intervention	1.09 (1.01, 1.21)	0.02	1.06 (1.0, 1.12)	0.04	1.03 (0.95, 1.11)	0.5

aRR: Adjusted Relative risk. GEE: Generalized Estimating Equations. All GEE models are adjusted for students enrolled, proportion of male students, proportion of Caucasian students, and proportion of students eligible for free or reduced-price meal program

^†High intensity intervention SBHCs had intervention scores >10

In the pre-post analysis among intervention SBHCs only, mean HPV vaccine uptake was 14% higher (95% CI: −4%, 35%) in the post-intervention period compared to pre-intervention period, adjusting for time and school-level factors (Table 2). Mean initiation rate was 4% higher (95% CI: −6%, 14%) while mean completion rate dropped by 9% (95% CI: −11%, 3%). However, none of these estimates were statistically significant.

SBHCs in schools that received more active intervention activities saw a 9% higher HPV vaccine uptake (95% CI: 1%, 21%) and 6% higher HPV vaccine initiation rate (95% CI: <1%, 12%) compared to SBHCs that received low intensity intervention (Table 2). There were no significant differences in HPV vaccine series completion between high and low intervention SBHCs.

Discussion

In this study, we found that a multicomponent vaccine promotion campaign implemented in SBHCs resulted in an increase in HPV vaccine uptake, although that increase was not statistically significant. We also found that HPV vaccine uptake in several intervention SBHCs was higher than the national average of 60% throughout the study period [36] and has been steadily increasing since before the intervention began. These findings reflect similar trends as other studies that have found high HPV vaccination rates among adolescents who use SBHCs [12,19,37–39].

Interim evaluation of the intervention done with the Kaiser Permanente Center for Community Health and Evaluation [40] showed that student champions were able to spark interest among peers about the benefits of HPV immunizations, awareness of HPV, and available services at SBHCs. Participation required low time commitment, which was important because students have busy schedules. Additionally, support and guidance from the PHSKC health educators was pivotal for the success of the intervention and for continued engagement of student champions. Overall, the report concluded that strong relationships between SBHCs and local health departments, youth engagement, and better outreach to parents in middle schools are necessary for the continued success of such programs.

Students that use SBHCs for medical visits would have been the most appropriate denominator to estimate vaccine uptake in SBHCs. However, SBHC medical records available to PHSKC for the purpose of this analysis did not include identifiers that could be linked to IIS vaccine records. As such, we were unable to determine the HPV vaccination eligibility for children making medical visits to SBHCs (However, SBHCs themselves have access to resources to determine vaccine eligibility for their clients and connect them to services). As an alternative, the denominator used was number of students who received vaccines at SBHCs based on records in WA-IIS, which is a subset of total SBHC patients. Hence, reported HPV vaccine rates could be elevated in this study because our study population is likely, a) more receptive towards vaccines, and b) are using SBHCs for vaccines instead of their primary care physicians. The advantage of using WA-IIS data, however, was that we were able to accurately ascertain users’ eligibility for receiving vaccine which improved our denominator.

The five control schools differed from intervention schools on several demographic characteristics and HPV vaccination rates at the start of the study period. A much lower baseline vaccine uptake rate in control SBHCs (Table 1) suggests that students in control schools might have greater barriers to accessing vaccination services outside of school. Barriers to access to community-based vaccination services such as place of residence, transportation to clinics, lack of awareness and knowledge about the HPV vaccine series, or lack of a regular medical home, are likely to affect vaccine coverage at SBHCs and are major unmeasured confounders in our study [35]. Other factors affecting baseline vaccine uptake that we did not account for are parental education, vaccine hesitancy among parents, and staffing limitations in SBHCs. Furthermore, we could not stratify by school type for effect of intervention intensity because there were no middle schools in the control group. Thus, our effect estimate comparing intervention SBHCs to control SBHCs could be biased and we could not make valid inferences about effect of intervention based on this modeling approach.

Our second approach was to match on schools and use pre-intervention time period as control period. Matching on school reduced confounding bias but decreased sample size. We observed an increase in vaccine uptake in the post-intervention period compared to the pre-intervention period, but the increase was not statistically significant. This may be because the baseline rates of vaccine uptake were already high (~70%) in some intervention SBHCs at the start of the study period. This led to a ceiling effect where any additional improvement in uptake due the intervention was difficult to detect. Furthermore, a strong temporal trend in vaccine uptake since before the implementation of the intervention explained most of the increase in vaccine uptake in the post-intervention period and it was difficult to ascertain how much of the increase was due to the intervention.

We found higher vaccine uptake and initiation in SBHCs in schools that received more active intervention activities. These findings suggest that having vaccine champions and several different types of campaign events had a greater impact on vaccine uptake. In middle schools, student-led campaign activities were not pursued in consideration of students’ age and stage of development. In these settings, other strategies where communication and framing was adjusted to speak more directly to the adult caregivers such as reminder-recall messages to parents, could have more impact as shown in other studies [41].

Since our outcomes were measured over time and were aggregated at the SBHC level, we had to separate the effects of time from effects of intervention and also account for the temporal correlation within SBHCs [31]. We included three years of pre-intervention data to properly assess existing temporal trends. We adjusted for calendar time by including it as a categorical variable in the GEE models. We adjusted for temporal correlation in outcomes specifying an exchangeable correlation structure in GEE models. This allowed us to estimate correct standard errors for the effects of intervention.

Limitations

Our study was not a randomized trial. Control schools with SBHCs were selected based on convenience. The implementation of the intervention was not uniform across schools. High school campaigns were mostly driven by student vaccine champions and depended heavily on sustained engagement of students and SBHC staff; this might be difficult to maintain from year to year and may differ between school settings. Due to logistical challenges and the realities of working with younger adolescents, middle schools received the intervention for only one school year, targeted parents rather than students, and relied on project and SBHC staff to lead campaign activities. This resulted in fewer post-intervention time periods than expected and further limited our ability to reliably estimate the effect of the intervention. Lastly, the study was conducted in a large, urban school district and may not be generalizable to private schools or schools in suburban or rural areas.

Conclusion

We evaluated the effect of a youth-led vaccination promotion program implemented in a school-based setting on HPV vaccine uptake, initiation, and completion in a non-randomized study. We found that the HPV vaccine uptake in students using Seattle’s SBHCs steadily increased between 2012 and 2018 and they are initiating the vaccine series earlier. HPV vaccine uptake and initiation were higher in the post-intervention period compared to pre-intervention period and SBHCs in schools that received more intervention activities for longer periods of time had higher HPV vaccine uptake and initiation rates. We conclude that promoting the use of SBHCs to receive HPV vaccines is an important strategy to improve HPV vaccine coverage among adolescents. Active student engagement, while successful in high schools, may not be adaptable to middle schools and other intervention strategies should be explored for younger students.