Human Papillomavirus Vaccine Series Research Articles

Reasons patients cite to their healthcare provider for not initiating or completing HPV vaccination.

Vaccination against the human papillomavirus (HPV) is critical to the prevention of HPV-associated cancers. This study aimed to describe the reasons cited by patients for not initiating or completing the HPV vaccination series, as reported by healthcare providers. Study data was obtained from a University of Texas MD Anderson Cancer Center population-based cross-sectional survey of healthcare providers practicing in Texas. Prevalence estimates of reasons cited for not initiating or completing HPV vaccination were estimated by patient population (i. parents of children and ii. adult patients). The study included 973 primary care providers, of which 45.53% were physicians and 54.47% were mid-level care providers. For parents who did not initiate the HPV vaccine for their child, the most commonly cited reasons were the belief that the vaccine was not needed (52.54%, 95% CI: 48.90-56.15), that the child was not sexually active (52.54%, 95% CI: 48.90-56.15), and safety concerns/side effects (47.05%, 95% CI: 43.44-50.69). Among age-eligible adults who did not initiate HPV vaccination, lack of knowledge and awareness was the most commonly cited reason (30.52%, 95% CI: 27.71-33.50). For non-completion of the HPV vaccine series, competing priorities was most commonly cited by parents (41.29% 95% CI: 37.76-44.91), followed by adverse reactions after the first dose (16.05%, 95% CI: 13.56-18.90). For non-completion of the HPV vaccine series among adults, competing priorities was also the most cited reason (31.04%, 95% CI: 28.20-34.02). These findings highlight the importance of addressing misconceptions and improving education about HPV vaccination to increase vaccination uptake rates and prevent HPV-related cancers.

Factors Associated with College Students' Human Papillomavirus (HPV) Vaccination and Preferred Strategies for Catch-Up Vaccine Promotion: A Mixed-Methods Study.

Human papillomavirus (HPV) vaccination protects against six types of cancer-cervical, anal, oropharyngeal, penile, vulvar, and vaginal. In the United States (U.S.), HPV vaccination coverage in college students remains low, especially in the Mid-South region, despite the highest risk of HPV infections and disease burden. However, few studies have assessed HPV vaccination among college students here. This study examined factors associated with HPV vaccination among college students in the Mid-South and explored preferred strategies for promoting vaccination. A mixed-methods design comprising a cross-sectional, self-report online survey and dyadic virtual interviews was conducted. Simple random sampling was performed to recruit a total of 417 undergraduate students aged 18-26 from March to May 2021; convenience sampling was performed to recruit three sex-matched dyads of a total of six (four female and two male) undergraduates from survey respondents who had not completed the HPV vaccine series in May 2021. Binary logistic regression analyses showed HPV vaccine knowledge and perceived barriers to vaccination were factors contributing to coverage for both female and male students, while perceived risks of HPV and vaccine hesitancy were factors only among female students. Findings from the qualitative content analysis identified college students' perceived barriers to the vaccination at multiple levels and preferred strategies for vaccination promotion, corroborating the findings from the survey study. The findings provide implications that benefit the development of tailored interventions aimed at facilitating catch-up vaccination among college students in the Mid-South region. There is an urgent need for further research and the implementation of effective strategies that address the identified barriers and improve HPV vaccine uptake in this population.

Incomplete HPV vaccination among individuals aged 27-45 years in the United States: A mixed effect analysis of individual and contextual factors.

10546 Background: In the United States, the Human papillomavirus (HPV) vaccine is approved for use up to age 45. Incomplete HPV vaccination rates among those over age 26, however, remain high. The aim of this study was to examine the independent effects of individual- and neighborhood-level factors on incomplete HPV vaccine series in the United States (US) among those aged 27-45 years. Methods: This retrospective cohort study used administrative data from Optum’s Clinformatics DataMart Database to identify individuals aged 27-45 years who received 1 or more doses of HPV vaccine between July 2019 and June 2022. Multilevel multivariable logistic regression models were applied to the data on 7,662 individuals aged 27-45 years who were fully vaccinated against HPV or not, nested within 3839 neighborhoods across the US. Results: More than half of the participants in this study (52.93%) were not completely vaccinated against HPV. About 64% of the eligible participants aged 27-30 years did not complete their HPV vaccine series. After adjusting for all other covariates in the final model, being older than 30 years old decreased the odds of incomplete HPV vaccine series. Participants living in neighborhoods of South region of the US had enhanced odds of incomplete HPV vaccine series compared to those residing in Northeast region (aOR 1.21; 95% CrI 1.03–1.42). There was significant clustering of incomplete HPV vaccine series at the neighborhood level. Conclusions: This study revealed that individual- and neighborhood-level factors significantly influence HPV vaccination incompleteness in the US. Interventions to improve HPV vaccination uptake and completion should take into consideration both individual- and contextual-level characteristics during design, planning and implementation of policies and programs to improve HPV vaccination coverage and completion in the US and other similar countries. Acknowledgement Dr. Adekanmbi is supported by a research career development award (K12HD052023: Building Interdisciplinary Research Careers in Women’s Health Program-BIRCWH; Berenson, PI) from the National Institutes of Health/Office of the Director (OD), National Institute of Allergy and Infectious Diseases (NIAID), and Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD). Dr. Guo is currently supported by an award (K07CA222343) from the National Institutes of Health, National Cancer Institute (NIH/NCI). Dr. Berenson is supported by an award (PP200048) from the Cancer Prevention and Research Institute of Texas (CPRIT). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or CPRIT. Conflict of Interest: All authors report no conflicts of interest.

Influences of sociodemographic characteristics and parental HPV vaccination hesitancy on HPV vaccination coverage in five US states

BackgroundIn the United States (US), half of new human papillomavirus (HPV) infections occur among young people aged 15–24 years. Despite the effectiveness of HPV vaccination in protecting against HPV-associated cancers, its coverage among adolescents remains suboptimal. This study examined the association of sociodemographic characteristics and HPV vaccination hesitancy with HPV vaccination coverage in five US states with disproportionately low adolescent coverage rates compared to the national average. MethodsResponses to an online Qualtrics survey from 926 parents of children aged 9–17 years in Arkansas, Mississippi, Missouri, Tennessee, and Southern Illinois in July 2021 were analyzed using multivariate logistic regression to estimate the association of sociodemographic characteristics and HPV vaccination hesitancy with HPV vaccination coverage. ResultsOf the parents, 78 % were female, 76 % were non-Hispanic White, 61.9 % lived in rural areas, 22 % were classified as HPV vaccine hesitant, and 42 % had vaccinated their oldest child between the ages of 9–17 years against HPV. Children of vaccine hesitant parents were less likely to have received any doses of the HPV vaccine than children of non-vaccine hesitant parents (AOR: 0.17, 95 % CI:0.11–0.27). Male children were less likely to have initiated the HPV vaccine series than female children (AOR: 0.70, 95 % CI:0.50–0.97). Older children (13–17 vs 9–12 years), receiving the meningococcal conjugate or most recent seasonal influenza vaccine were all associated with higher likelihoods of receiving any doses of the HPV vaccine (AOR: 6.01, 95 % CI:3.98–9.08; AOR: 2.24, 95 % CI:1.27–3.95; AOR: 2.41, 95 % CI:1.73–3.36, respectively). ConclusionsAdolescent HPV vaccination coverage remains low in our targeted states. Children’s age, sex, and parental vaccine hesitancy were significantly associated with likelihood of HPV vaccination. These findings offer the opportunity for targeted interventions among parents in regions with low vaccine uptake and underscore the importance of developing and implementing strategies to address parental HPV vaccination hesitancy to improve uptake in the US.

Does Bundling Matter? The Effect of Providing HPV Vaccination Before Tdap Vaccination on Timely Completion of the HPV Vaccine Series [ID: 1381348

INTRODUCTION: The American Academy of Pediatrics and American Cancer Society promote vaccine initiation at age 9 as one way to improve human papillomavirus (HPV) vaccination rates. Studies have noted increased HPV vaccine series completion rates when the series was begun before age 11. We used a national sample to assess the effect of initiating the HPV vaccine series initiation prior to the adolescent platform on timely series completion. METHODS: To explore the effect of initiating the HPV vaccine series prior to other vaccines in the adolescent platform (unbundling) on timely series completion, we created a cohort of children aged 9 in 2015 who were continuously enrolled through the age of 13 (2019) from a national administrative database of employee-sponsored insurance (MarketScan). Logistic regressions were used to predict the odds of HPV vaccine series completion among those who started the series prior to, concurrent with, or after receiving tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination. The cohort included 100,857 eligible children. RESULTS: Compared with adolescents who received their HPV and Tdap vaccinations concurrently, those who received HPV prior to Tdap had higher completion (adjusted odds ratio [aOR], 1.38), whereas those who received their HPV vaccination after Tdap had lower odds of HPV vaccine series completion (aOR 0.68). Other factors associated with series completion included female sex, residing in an urban (versus rural) area, residing in the Northeast, and receiving primary care from a pediatrician (versus family medicine physician). CONCLUSION: These data indicate that beginning the HPV vaccine series prior to the adolescent platform (unbundling) may improve on-time series completion.

Incomplete HPV Vaccination among Individuals Aged 27-45 Years in the United States: A Mixed-Effect Analysis of Individual and Contextual Factors.

Background: In the United States, the human papillomavirus (HPV) vaccine is approved for use in individuals up to age 45. Individuals 15 years and older require three doses of the vaccine to complete the recommended dosing series. Incomplete HPV vaccination rates (i.e., one or two doses) among those over age 26, however, remain high. This study examined the independent effects of individual- and neighborhood-level factors on incomplete HPV vaccination rates in the United States (U.S.) among those aged 27-45 years. Methods: This retrospective cohort study used administrative data from Optum's de-identified Clinformatics® Data Mart Database to identify individuals aged 27-45 years who received one or more doses of HPV vaccine between July 2019 and June 2022. Multilevel multivariable logistic regression models were applied to the data on 7662 individuals identified as being fully or partially vaccinated against HPV, nested within 3839 neighborhoods across the U.S. Results: Approximately half of the patients in this study (52.93%) were not completely vaccinated against HPV. After adjusting for all other covariates in the final model, being older than 30 years old decreased the odds of not completing the HPV vaccine series. Participants living in South-region neighborhoods of the U.S. had enhanced odds of not completing the vaccine series compared with those residing in Northeast-region neighborhoods (aOR 1.21; 95% CrI 1.03-1.42). There was significant clustering of incomplete HPV vaccination rates at the neighborhood level. Conclusions: This study revealed that individual- and neighborhood-level factors were associated with the risk of not completing the HPV vaccine series among individuals aged 27-45 years in the U.S. Interventions to improve HPV vaccination series completion rates for this age group should take into consideration both individual and contextual factors.

Abstract 5539: Assessing knowledge, vaccine hesitancy, and completion rates of free HPV vaccination in uninsured/underinsured low-income patients

Abstract Background: Human Papillomavirus (HPV) vaccination rates remain low in the U.S., particularly among minorities and low-income patients. In 2014, a Mayo Clinic study of uninsured, low-income, working, Volunteer in Medicine (VIM) Clinic patients in Jacksonville, Florida found a statistically significant lower awareness of HPV (50.3% vs 63.6%) and the HPV vaccine (32.1% vs 62.7%) than the national population. As a result, our team collaborated with Merck to develop a free HPV vaccination program and video education campaign for VIM patients. Methods: We assessed VIM patients HPV vaccination knowledge, awareness, and prevalence of hesitancy towards receiving the vaccine. VIM patients (ages 18-45) with no previous history of HPV vaccination were invited to participate in this study. The Parents Attitudes about Childhood Vaccines (PACV) survey was used to evaluate vaccine hesitancy. Patients who declined the HPV vaccine were shown an educational video to assess effectiveness in persuading patients’ opinion. Each participant received a vaccine hesitancy PACV score, which was compared with their vaccine disposition. Mayo Clinic IRB approval of the study was obtained. Results: Our analysis included 43 patients (34 females, 9 males) with a median age of 40 (age range 27- 45). Patients had overall knowledge of HPV of 88.4%, with 69.8% having heard of the HPV vaccine. 85.7% PACV survey respondents were deemed non-hesitant (PACV scores 0-49), and 80.6% of the non-hesitant subset (29/36) agreed to undergo vaccination. The average PACV score of vaccine-interested participants was lower (25.2) than the average of participants not interested in the vaccine (36.7). Black participants had a statistically significant higher PACV score than White participants. The PACV scores of individuals who were already familiar with the HPV vaccine were significantly lower than those of participants who were unfamiliar with the HPV vaccine. Only 20% (2/10) of individuals, who had previously declined vaccination, agreed to receive the HPV vaccine after viewing the HPV educational video. Of the 33 participants who agreed to receive the free HPV vaccine, only 9 (27.3%) completed all three doses. Conclusions: HPV vaccine awareness and knowledge at VIM increased compared to the 2014 cohort. Vaccine hesitancy was not observed in most patients, yet video education was effective in only a small portion of patients with vaccine hesitancy. Additionally, a minority of patients who agreed to receive the free HPV vaccine series completed all three doses. Our results suggests that free HPV vaccination and video education is not sufficient to achieve adequate vaccination rates among low-income uninsured young adults, nor overcoming vaccine hesitancy. Innovative measures are warranted to improve vaccination rates in this population. Citation Format: Hiram Diaz, Gerardo Colon-Otero, Laura M. Pacheco-Spann, Christopher C. DeStephano, Sandra Casanova-Leyva. Assessing knowledge, vaccine hesitancy, and completion rates of free HPV vaccination in uninsured/underinsured low-income patients. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5539.

Are Interventions Efficacious at Increasing Human Papillomavirus Vaccinations Among Adults? A Meta-Analysis.

A variety of intervention strategies to improve Human Papillomavirus (HPV) vaccination rates in adults exist; however, they have shown varying efficacy and inconsistent outcomes. This meta-analysis tested the efficacy of HPV vaccination interventions for adults in increasing vaccine intentions, rates of initiation of the vaccine series, and completion rates. The study also tested potential moderators (intervention strategy, theory-based versus nontheory-based interventions, race/ethnicity, gender, study quality) of relationships between intervention receipt and vaccine intentions. Electronic databases (PsychINFO, Web of Science, Scopus, EBSCO, JSTOR, PubMed) were searched for English-language articles published up to September 2021. Eligible studies included outcomes of vaccine intentions, receipt of the first dose, or vaccine series completion and included intervention and comparison conditions. The search yielded 38 eligible studies reporting 78 effect sizes. Random effects, multilevel, meta-analytic models revealed a significant, small effect of interventions on vaccine intentions (OR = 0.36, 95% CI [0.07, 0.65]); a nonsignificant effect on vaccine initiation rates (OR = 1.29; 95% CI [0.87, 1.91]); and significant effects on vaccine completion rates (OR = 1.58, 95% CI [1.18, 2.11]). Race/ethnicity, gender, intervention strategy, theory-based interventions, and study quality did not moderate the intervention effects on vaccine intentions. Evidence supports the efficacy of interventions to increase intentions to receive the HPV vaccine and completion of the HPV vaccine series in adults. However, evidence did not support the efficacy of interventions to increase HPV vaccine initiation. Findings highlight directions for developing more efficacious HPV vaccine interventions for adults.

65. Assessing Compliance with Human Papillomavirus Vaccination Series in Patients with Cloacal Malformations in a Multidisciplinary Clinic

65. Assessing Compliance with Human Papillomavirus Vaccination Series in Patients with Cloacal Malformations in a Multidisciplinary Clinic

Adjuvant Human Papillomavirus Vaccination After Excisional Procedure for Cervical Intraepithelial Neoplasia: A Cost-Effectiveness Analysis.

To examine the cost effectiveness of human papillomavirus (HPV) vaccination after excisional procedure compared with no vaccination. We constructed a decision-analytic model (TreeAge Pro 2021) to compare outcomes between patients who underwent an excisional procedure followed by nonavalent HPV vaccination to those who underwent an excisional procedure without vaccination. Our theoretical cohort contained 250,000 patients, the approximate number undergoing excisional procedures annually in the United States. Our outcomes were costs, quality-adjusted life-years (QALYs), recurrence events, number of surveillance Pap tests with co-testing, number of colposcopies, and second excisional procedures. Probabilities of recurrence were based on a recently published meta-analysis. All values were derived from the literature, and QALYs were discounted at a rate of 3%. Outcomes were applied for 4 years after the initial excisional procedure. Our cost-effectiveness threshold was $100,000 per QALY. Sensitivity analyses were performed to evaluate the robustness of the model. In our theoretical cohort of patients who underwent an excisional procedure, the HPV vaccination strategy was associated with 17,281 fewer recurrences of cervical intraepithelial neoplasia (CIN) (8,360 fewer cases of CIN 1 and 8,921 fewer cases of CIN 2 or 3), 26,203 fewer Pap tests (1,025,368 vs 1,051,570), 17,281 fewer colposcopies (20,588 vs 37,869), and 8,921 fewer second excisional procedures (4,779 vs 13,701). The vaccination strategy was associated with a higher cost of $135 million. Vaccination was a cost-effective strategy, with an incremental cost-effectiveness ratio of $29,181 per QALY, compared with no vaccination. In our sensitivity analyses, the HPV vaccination strategy remained cost effective until the cost of the three-dose HPV vaccine series reached $1,899 or the baseline (nonvaccinated) probability of recurrence was less than 4.8%. In our model, HPV vaccination for patients with a prior excisional procedure led to improved outcomes and was cost effective. Our study suggests that clinicians should consider offering the three-dose HPV vaccine series to patients who have undergone an excisional procedure to decrease the risk of CIN recurrence and its sequelae.

Factors Affecting Completion of Human Papillomavirus Vaccination Series by Gender in a Predominantly Hispanic Border Town Community.

The human papillomavirus (HPV) vaccine is recommended for females and males aged 9 to 45. Nationally, the HPV vaccination rates are lower for males than females; however, this has not been studied in a US-Mexico border community. Our study aims to report the HPV vaccination completion by gender and determine which sociodemographic factors influence vaccination. This cross-sectional study was conducted among uninsured and underinsured individuals aged between 9 and 26 years served through a community-based HPV vaccine program in El Paso, TX. Data collected included demographic information, psychosocial variables, and vaccine administration data. Descriptive statistics were used to summarize demographic data. Unadjusted t test/Fisher exact test and multivariable relative risk regression were run on significant variables to determine the association with vaccine completion by gender. Most participants were female (63.4%), and an overall vaccine series completion was 30.67%. We found no significant difference in HPV vaccine completion rates by gender. Males who resided in the United States for more than a decade were 31% more likely to complete the vaccine series, and females who had 9 to 13 years of education had lower odds of vaccine completion. Knowledge significantly increased after the intervention for both genders (p = .002). There was no significant change in psychosocial variables from the preintervention to the immediate postintervention survey. Our multicomponent, culturally tailored intervention may equally impact male and female participants and encourages all genders to complete their HPV vaccine series. Additional studies with a larger male sample are needed.

Assessment of human papillomavirus vaccination rates of adolescents in California, 2018–2019

Accurate documentation of state-level human papillomavirus (HPV) vaccination is required for public health planning and to inform corrective actions. To examine the representativeness of the California Immunization Registry, we compared the National Immunization Survey (NIS)-Teen, commercial HMOs in California, Medi-Cal, and California Immunization Registry data for HPV vaccine series completion. Our objectives were to evaluate the vaccine registries, compare and report their completeness, and make recommendations on how to improve and use these studies. Vaccination values were extrapolated for all adolescents aged 13 to 17 years from 2018 to 2019 from NIS-Teen, adolescents aged 13 years from 2018 to 2019 reported in the California Immunization Registry, and adolescents aged 13 years for 2018 for commercial HMOs and Medi-Cal. HPV series completion among 13-year-olds in 2018 for commercial HMOs was 50 %, Medi-Cal was 45 %, and the California Immunization Registry was 28 %, with NIS-Teen rates for 13 to 17-year-olds at 50 % in 2018 and 54 % in 2019. Both rural and urban geographic regions were found to have low completion rates of the HPV series, with trends ranging from 13 % to 45 %. The California Immunization Registry’s lower HPV vaccine series completion among 13-year-olds compared to the other reporting sources is most likely due differences in reporting and data collection. Importantly, this data will serve as a comparator for future, similar studies of various sources of HPV vaccination rates following the passing of Bill-1797, which will mandate immunization reporting starting in January 2023.

Integrated Health Maintenance Reminders for Improved HPV Vaccine Administration: TowardImprovements in Completion Disparities.

To evaluate the effect of a health maintenance reminder (HMR) on human papillomavirus (HPV) vaccine administration and completion across different age, insurance, and race cohorts. Retrospective pre-post analysis. Academic primary care. Patients aged 9 to 26 who had initiated the HPV vaccine series from 2016 to 2021 were analyzed, based on current age-based standards. The cohort was divided based on vaccine uptake before and after the implementation of the HMR program in February 2020. The multivariate analysis estimated the odds of vaccine completion based on sociodemographic factors, and variable interactions were investigated to determine independent associations between sociodemographic factors and HMR implementation. There were 7654 individual patients (mean age was 15.8 years; 46.7 were males; and 50.7% were white). HPV vaccine completion rates increased post-HMR implementation by 59.2% (37% pre-, and 58.9% post-HMR; p < .001) in the entire cohort. Overall, black patients (adjusted odds ratio [aOR] = 0.68; 95% confidence interval [CI]: 0.60, 0.70) and patients ≥18 years (aOR = 0.13; 95% CI: 0.11, 0.15) were significantly less likely to complete their vaccine series; however, this improved significantly following HMR in these groups (p < .001). Post-HMR, race, and insurance status were not independently associated with disparate vaccine completion rates, however,age was, and patients ≤14 or younger had higher odds of vaccine completion (aOR = 3.54; 95% CI: 2.91, 4.32). The implementation of an HMR was associated with increased HPV vaccine uptake across age and race groups in this single-institution study. Future research should explore barriers to implementing HMRs in different health care settings.

HPV vaccine initiation at 9 or 10 years of age and better series completion by age 13 among privately and publicly insured children in the US

ABSTRACT The US Advisory Committee on Immunization Practice recommends routine human papillomavirus (HPV) vaccination at 11–12 years of age, but states that vaccination may be initiated as early as 9 years. Our primary goal was to assess whether initiating HPV vaccination at 9–10 years of age, compared to 11–12, was associated with a higher rate of series completion by 13 years of age, and to identify factors associated with series completion by age 13. The study used vaccine claims and other data from the IBM MarketScan Commercial Claims and Encounters (privately insured) and IBM MarketScan Multi-State Medicaid (publicly insured) databases. Participants were 9–12 years of age and initiated HPV vaccination between January 2006 and December 2018 (publicly insured) or February 2019 (privately insured). Among 100,117 privately insured individuals, those initiating the HPV vaccination series at 9–10 years of age had a significantly higher series completion rate by 13 years of age than did those initiating at 11–12 years of age (76.2% versus 48.1%; p < .001). The same pattern was observed for 115,863 publicly insured individuals (70.4% versus 40.0%; p < .001). Provider and health care plan type, female sex, race/ethnicity, and wellness checks or non-HPV vaccinations during the baseline period were significantly associated with series completion by 13 years of age. Proactive initiation of HPV vaccination at 9–10 years of age was associated with higher rates of series completion by 13 years of age. These findings can inform provider education and other interventions to encourage timely HPV vaccination series completion.

Descriptive epidemiology of age at HPV vaccination: Analysis using the 2020 NIS-Teen

ABSTRACT Human papillomavirus (HPV) vaccination uptake in the United States remains suboptimal, and continues to trail that of tetanus, diphtheria, and acellular pertussis (Tdap) vaccination and quadrivalent meningococcal conjugate vaccination (MCV4). This is despite these three vaccines all being recommended for routine adolescent use within the 2005–2006 time period. One strategy to improve HPV vaccination is starting the vaccine series at the first opportunity – currently as young as 9 years of age. Little is known about the epidemiology of age at HPV vaccination, and the frequency of vaccination occurring at 9–10 years of age. Using 2020 National Immunization Survey-Teen (NIS-Teen) data, we analyzed age at HPV vaccine initiation and proportion of initiators completing the HPV vaccine series relative to age at initiation. Overall, 4.0% of US adolescents initiated HPV vaccination at 9–10 years of age, with higher initiation among younger birth cohorts (4.8% for 13-year-olds and 5.1% for 14-year-olds) than older cohorts (3.1% for both 16 and 17 year-olds). Age cohorts maximized HPV vaccine completion after 3–4 years. Among those initiating at ages 9–10, 93% of 13-year-olds completed the series. Among those initiating at 11–12, completion rates rose from 66% among 13-year-olds to 90.2% among 16-year-olds. Among those initiating at age 13–14, completion rose from 61% among 15-year-olds to 84.9% among 17-year-olds. This manuscript serves as a starting point of comparison for future epidemiologic evaluations of HPV vaccination at the first opportunity.

Abstract P018: Differences in guideline-recommended age of human papillomavirus (HPV) vaccine initiation and completion in the United States

Abstract Background: While there has been increase in the uptake of the human papillomavirus (HPV) vaccine, current vaccine rate fell short of the Healthy People 2020 target. The Centers for Disease Control and Prevention (CDC) recommends that the vaccine be routinely administered to children between 11 and 12 years and could begin as early as 9 years of age. However, it is unclear to what extent the CDC’s guideline-recommended age of HPV vaccine uptake is followed. Objective: To test the hypothesis that HPV vaccine uptake is more likely at an older age in the United States rather than the CDC recommended age of 11-12 years. Methods: We analyzed the 2017-2020 nationally representative, cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) for respondents between 9 and 17 years of age, grouped as 9-10 years, 11-12 years, and 13-17 years. Outcome of interest was age of HPV vaccine uptake (initiation and completion), based on the above age groups. We estimated odds of vaccine uptake by age, using logistic regression models, and adjusted for covariates, including sex, race/ethnicity, income, and healthcare access. Results: There were 2,584 participants in our study. However, while 22% were aged 9-10, only 5.7% in this age group had initiated the vaccine. In crude analysis, there was a significant difference in in age of vaccine uptake (both initiation and completion) across age groups (p &amp;lt; .0001). After adjusting for covariates, we found significant associations between age and HPV vaccine uptake. Compared to participants aged 11-12 years, adolescents aged 13-17 years had over double the odds of initiating (aOR = 2.57; 95% CI 1.88, 3.51) or completing (aOR = 2.67; 95% CI 1.76, 4.06) the HPV vaccine series. However, younger individuals between 9-10 years were less likely to initiate (aOR = 0.14; 95% CI 0.09, 0.22) or complete the vaccine series (aOR = 0.19; 95% CI 0.09, 0.37). Conclusions: While the CDC recommends HPV vaccine uptake between 11-12 years of age and as early as 9 years, individuals are significantly more likely to receive the vaccine as adolescents, and less likely to receive the vaccine between 9-10 years of age. Future studies will determine patients vs. provider factors driving this difference in recommended age of vaccine uptake compared to reported age of uptake. Citation Format: Trinity Casimir, Marian F. Talip, Dina K. Abouelella, Mrudula Nair, Daniel J. Rocke, Tammara L. Watts, Nosayaba Osazuwa-Peters, Eric Adjei Boakye. Differences in guideline-recommended age of human papillomavirus (HPV) vaccine initiation and completion in the United States. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P018.

Abstract A127: Factors impacting HPV vaccine initiation among English and Spanish speaking parents of Latino adolescents

Abstract Background: Human Papillomavirus (HPV)-associated cancers disproportionately impact Latinos. While data for English-speaking (ES) and Spanish-speaking (SS) Latinos is usually aggregated, differences in acculturation, sociodemographic characteristics, and health behaviors make it important to understand the factors impacting HPV vaccination among these groups separately. This understanding is crucial to improving HPV vaccination disparities as COVID-19 vaccinations have exacerbated issues of vaccine hesitancy and medical mistrust. Methods: Self-administered online surveys examining HPV vaccine hesitancy in an urban, diverse community with low HPV vaccine uptake were completed by parents of adolescents (N=357) in English or Spanish. Bivariate logistic regression analyses were conducted to understand if medical mistrust, vaccine hesitancy, HPV knowledge, healthcare utilization and sociodemographic factors impact adolescent HPV vaccine uptake among ES and SS parents of Latino adolescents ages 12-17. Factors significant at p&amp;lt;.01 in the bivariate analyses were included in multivariable logistic regression models for each group. Results: 136 parents of adolescents aged 12-17 identified as Latino; 56% completed the survey in English and 44% in Spanish. Bivariate analyses found significant associations between decreased HPV vaccine uptake and male parent/caregiver sex, higher HPV vaccine hesitancy, higher HPV knowledge, male adolescent sex, not receiving the flu vaccine and not receiving a provider recommendation to vaccinate against HPV among ES parents. In SS parents, parents aged 41-50 (compared to &amp;lt;40) and higher medical mistrust were associated with higher HPV vaccination; while male adolescent gender, not receiving TDAP immunization, and not receiving a provider recommendation to vaccinate against HPV were associated with lower HPV vaccine uptake. Multivariable regression models found that adolescents of ES parents were less likely to have initiated the HPV vaccine series if the parent/caregiver was male (OR=0.07, 95% CI:0.03,1.28), had higher HPV knowledge (OR=0.53, 95% CI:0.29,0.96), and did not receive a provider recommendation to vaccinate against HPV (OR=0.12, 95% CI:0.003,0.55). SS parents with higher medical mistrust (OR=7.27, 95% CI:1.14,46.41) and those aged 41-50 compared to parents younger than 40 (OR=18.19, 95% CI:0.28,407.78) were more likely to have adolescents who initiated the HPV vaccine series, while those without a provider recommendation to vaccinate had lower odds of HPV vaccine uptake (OR=0.004, 95% CI:&amp;lt;0.01,0.11). Discussion: Aligned with the literature, provider recommendation to vaccinate against HPV significantly impacted vaccination behavior among ES and SS parents. Interventions should focus on improving provider recommendations and communications with Latino parents of adolescents. More research should explore the surprising associations between higher medical mistrust and higher odds of HPV vaccination among SS parents, and more HPV knowledge and lower odds of HPV vaccination among ES parents. Citation Format: Bibiana Martinez, Lourdes Baezconde-Garbanati, Jennifer Tsui. Factors impacting HPV vaccine initiation among English and Spanish speaking parents of Latino adolescents [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A127.

Relevancy Between Knowledge and Attitudes of Students to Human Papillomavirus (HPV) Vaccine: Literature Review

Background: University students are the key population to be prioritized in terms of uptake and coverage of the HPV vaccine. HPV program policies have recently shifted to target pre- and early pubertal adolescents before the age of 13 years. Evidence shows that adolescents aged 13 and over are less likely to complete the HPV vaccine series. Currently, 23 million young adults aged 19-26 years are not vaccinated. In 2016, only 16% of unvaccinated children aged 13 to 17 years received both doses. In addition, adolescents are less likely to start the HPV vaccine as they age, with only 7% initiation after age 15. Such lower vaccination rates raise the need for an effective follow-up vaccination strategy that targets young populations beyond the recommended adult vaccination schedule. In fact, the CDC’s Advisory Committee on Immunization practices recently recommended expanding the vaccination age range to 26 for both men and women, and for clinicians to engage in shared decision-making with older patients (ages 27-45) who might benefit of its use. Method: This article using method literature review. It is use selected journals or articles according to the author’s criteria and analyzing them to produce a conclusion. Authors using two international database is Pubmed and Sciencedirect with the keyword “knowledge and attitudes”, “students”, and “HPV vaccine”. The analysis of the articles used is based on the publication time span of the last 5 years (2018- 2022). The type of journal used is original, full text, and open access. The design of this article was taken using case control and cross-sectional methods. Result: The result of a literature search on database by Pubmed and Sciencedirect, there are 407 journals according to keywords and time spans. There are 122 journals from Pubmed and 285 journals from Sciencedirect. Authors filtered by the title, abstract, method, and result to find relevancy between knowledge and attitudes of students to HPV Vaccine. Total of 20 articles related to this article. Conclusion: On average, studies from various journals state that their findings have a lot to do with knowledge and attitudes towards the HPV vaccine, so it is advisable to further promote this knowledge so that there will be more students’ positive attitudes towards the HPV vaccine.

Factors Associated with HPV Vaccine Adherence among Latino/a Adolescents in a Rural, Texas-Mexico Border County.

Completion of human papillomavirus (HPV) vaccine series among Texas Hispanic adolescents is low compared to national data. We examined the association between HPV vaccine initiation and completion among Hispanic adolescents in a rural, Texas-Mexico border county and specific individual and neighborhood-level characteristics. Cross-sectional analysis of data from a broader cancer prevention program. Underserved colonias communities in a Texas-Mexico border county. Hispanic mothers or caregivers (n=712) and adolescents aged 11-17 years (n=1120) linked to publicly available data about their neighborhood. HPV vaccine adherence (ie, initiation and completion) as reported in either the Texas Immunization Registry or adolescents' electronic medical records, measured at the end of the cancer prevention program. Logit and multi-level mixed-effects logistic regression of individual- and neighborhood-level data. Factors associated with HPV vaccine initiation and completion were female gender (P<.01), adolescent insurance status (P<.001), and receipt of required vaccines (P<.001). After controlling for neighborhood-level characteristics, only receipt of required vaccines remained significant. Findings indicate a relationship between Hispanic adolescents' receiving the required vaccine series for school admission and HPV vaccine initiation and completion. In resource-limited settings like federally qualified health centers, further efforts should focus on implementing best practices at both the provider level (eg, education on bundled vaccine recommendation) and practice-level (eg, outreach and support by trained immunization navigators).

Human papillomavirus vaccinations at recommended ages: How a middle school-based educational and vaccination program increased uptake in the Rio Grande Valley

ABSTRACT Human papillomavirus (HPV) vaccination is recommended for U.S. adolescents at ages 11–12 requiring two or three doses depending on if the vaccine series started before age 15. The objective was to compare HPV vaccination rates among medically underserved, economically disadvantaged, students in rural middle school districts (Rio Grande Valley [RGV], Texas) by age of initiation (≤ age 11 years vs. age 12 years and older). This quasi-experimental study included 1,766 students (884 females; 882 males) who received at least one HPV vaccine dose through our school-based vaccination program between 08/2016-06/2022. Summary statistics were stratified by age at initiation and gender. The overall HPV up-to-date (UTD) rate was 59.7% (95% Confidence Interval: 57.4–62.0%). The median age at HPV UTD (range) was 12 years (9–19) and median interval between HPV vaccine doses (range) was 316 days (150–2,855). Most students received the HPV vaccine bundled with other vaccinations (72.4%, 1,279/1,766). There was a higher HPV UTD rate among students who initiated the HPV vaccine on or before age 11 than those who initiated on or after age 12 (73.6% versus 45.1%, respectively). The median age of HPV UTD was age 12 for those initiating on or before 11 years versus age 13 for those initiating on or after 12 years of age. Initiating the HPV vaccine at age ≤11 years increased completion of the HPV vaccine series. Improving HPV vaccine coverage and introduction of pan-gender vaccination programs will significantly decrease HPV-related diseases in the RGV.