An interventional study of (Intervention) Recommending HPV vaccine for patients 9-10 years of age and (Control) Recommending HPV vaccine for patients 11-12 years of age in HPV, sponsored by University of Colorado, Denver. Completed at 2 sites in United States. Open to participants aged 9 Years to 13 Years. Per ClinicalTrials.gov, last updated 2026-07-16.
Sponsored by University of Colorado, Denver · Not applicable, Interventional, and Health services research
Every year, thousands of Americans die from cancers related to human papillomavirus (HPV). The vast majority of those deaths could be prevented with a safe and effective vaccine, yet many parents choose not have their children vaccinated when it is recommended at age 11 or 12. In this study, we will examine in a randomized trial whether earlier initiation of the vaccine at age 9-10 years will result in less parental refusal and higher rates of full vaccination at younger ages, before early sexual activity begins.
The burden of Human Papillomavirus (HPV)-related disease in the US is substantial. A safe and effective vaccine has been available for >10 years, yet the current rate of completion for the HPV series is only 49% for U.S.13-17 year olds. The Advisory Committee on Immunization Practices (ACIP) recommends routine HPV vaccination at age 11-12 years (yrs), but states that the vaccine "can be given starting at age 9 years." Currently, the majority of pediatricians begin recommending the vaccine at ages 11-12 yrs, however, a recent retrospective study showed that on-time completion rates for HPV vaccine were much higher when the vaccine series was initiated at ages 9-10 compared to ages 11-12 (adjusted odds ratio, 12.8).
HPV vaccine should be given prior to sexual activity which occurs earlier than 13 yrs for many teens. There are compelling reasons to think that earlier initiation of vaccination at ages 9-10 might result in higher rates of acceptance of the vaccine and earlier series completion. First, many parents refuse HPV vaccine because they have concerns that vaccination could result in higher promiscuity in early adolescents if the vaccine is discussed in the context of sexuality. Initiation at 9-10 yrs, when few providers discuss sex, could put the focus squarely on cancer prevention, decreasing vaccine refusal. Second, three vaccines are recommended at the 11-12 yr visit, but many parents/adolescents are unwilling to receive all three at one visit. When one of the vaccines is delayed, it is almost always HPV vaccine. Initiation at 9-10 yrs when no other vaccines are given could result in less deferral of vaccination to mid-adolescence and higher rates of vaccination prior to early sexual activity. Finally, initiation at age 9-10 years has been shown to be feasible and, in an observational study, to result in higher rates of on-time series completion.
Therefore, we plan to test the effectiveness of shifting initiation of HPV vaccine to 9-10 yrs in a randomized pragmatic trial. Our Specific Aims are to: SA 1: Recruit practices in two states (Colorado and California), randomize in a balanced fashion to recommending HPV vaccine at ages 9-10 yrs or 11-12 yrs and provide standardized training to both arms. SA 2: Conduct a trial to assess effectiveness of early initiation on the primary outcome of age at HPV series completion; secondary outcomes will examine HPV series completion by age 13 and age at HPV series initiation. SA 3: Examine the effect of earlier initiation on length of time for HPV vaccine discussions and on parent/provider communication about HPV vaccine via audio-taping of visits, audio-elicitation interviews with parents and structured interviews with providers and clinic staff.
If earlier HPV initiation is successful in promoting higher HPV series completion by 13 yrs, this intervention could be rapidly disseminated and would have the potential to prevent thousands of cases of HPV-related cancers, their attendant morbidity and mortality as well as the costs of screening, diagnosis and treatment for these cancers yearly.
University of Colorado, Denver is the lead sponsor of 1,499 studies on the registry; 315 are open to participants now.
Of its 139 completed or terminated interventional studies of FDA-regulated products, 89 (64%) have results posted.
Counted across the registry records on this site, refreshed daily.
Practices:
Inclusion Criteria:
Exclusion Criteria:
Patient Eligibility Criteria
Patients attributed to practices routinely recommending HPV vaccine starting at 9-10 years of age.
Behavioral: (Intervention) Recommending HPV vaccine for patients 9-10 years of age
Patients attributed to practices routinely recommending HPV vaccine starting at 11-12 years of age.
Behavioral: (Control) Recommending HPV vaccine for patients 11-12 years of age
Practices are randomized to receive training on how to recommend HPV vaccine, including both standardized communication strategies and strategies for switching from 11-12 years to 9-10 years including: challenges with 11-12 strategy, long-term immunity, success of other practices and tips to help standardize to age 9-10. Trainings will be a combination of online and in-person or virtual. Annual trainings will be offered and providers will receive Maintenance of Certification credits (MOC) for participating. Providers will routinely recommend HPV starting at age 9 for all patients -- which is already approved for this vaccine but is not routinely recommended at age 9 years.
Control practices will receive a training on standardized communication for HPV vaccine including: using strong recommendations, using presumptive recommendation, providing specific phrases to use with parents, answering common questions and, HPV vaccine as a cancer prevention. Annual trainings will be offered and providers will receive professional development credit (MOC).
Age at completion of two dose HPV series
The primary outcome will be age at completion of the two dose HPV series. This is a time-to-event outcome, with the event of interest being vaccine completion. Comparisons between the intervention practices and control practices will be made. Practice electronic health records will be used to assess this outcome.
Time frame: post-intervention assessed in year 5 of study, year 4 of trial
HPV completion by age 13 years
Secondary outcome will be HPV series completion rates by age 13. This will be a binary outcome. Comparisons between the intervention practices and control practices will be made. Practice electronic health records will be used to assess this outcome.
Time frame: post-intervention assessed in year 5 of study, year 4 of trial
Age at initiation of the HPV series
This is a time-to-event outcome, with the event of interest being vaccine initiation. Comparisons between the intervention practices and control practices will be made. Practice electronic health records will be used to assess this outcome.
Time frame: post-intervention assessed in year 5 of study, year 4 of trial
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — The study team guarantees that any and all data collected as part of this project will be released in accordance with standard data sharing policies and procedures to validate research findings if requested. Data will be made available in a timely manner to the broader scientific community, and will be complete, and as accurate as possible. All data released will be de-identified, with no information that could be linked to any study subjects, or participating study practices in order to ensure the confidentiality of all subjects and practices. If necessary, a data use agreement will be established.
Supporting information: Study protocol, Sap
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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University of Colorado, Denver