Human Papillomavirus Vaccine Series Research Articles

HPV multilevel intervention strategies targeting immunization in community settings (HPV MISTICS): Study protocol for a hybrid 1 stepped-wedge cluster randomized trial.

This protocol paper describes the overall design for HPV MISTICS, a multilevel intervention to increase human papillomavirus (HPV) vaccination initiation and completion rates among adolescents aged 11-17. We will conduct a hybrid type 1 implementation-effectiveness trial using a stepped-wedge cluster randomized trial in eight federally qualified health centers (FQHCs) in Florida. Intervention components target three levels: system, providers, and parents. Outcomes will be assessed using quantitative (e.g., vaccination data, survey data) and qualitative methods (e.g., staff and parent interviews). We expect to quantify changes in HPV vaccine series initiation and completion rates for adolescents ages 11-17 in the eight FQHCs. We have hypothesized a 20-percentage point increase in HPV vaccine series initiation and a 10-percentage point increase in series completion. We also anticipate being able to explore factors at the system, provider, and patient levels as potential covariates. Implementation outcomes, barriers, and facilitators identified in the study will help characterize the implementation process and inform potential future intervention scale-up. The project is ongoing; effectiveness and implementation outcomes will be determined following project completion. Findings will provide evidence of an equity-informed research design and implementation procedures that could help improve HPV vaccination rates in similar health systems. NCT05677360 (date registered: 2022-12-22); https://clinicaltrials.gov/study/NCT05677360?lead=Moffitt%20Cancer%20Center%20&aggFilters=status:rec&page=2&rank=17.

Effect of age at initiation of the human papillomavirus vaccine on the association between race/ethnicity and completion of the vaccine series

BackgroundUp-to-date (UTD) of the human papillomavirus (HPV) vaccine series has been low despite 2016 recommendations for 2 doses among initiators <15 years of age and 3 doses for 15+ year olds. This study examined how age at initiation affected the association between race/ethnicity and UTD among adolescent HPV vaccine initiators. We also examined how administration of other adolescent vaccines affected UTD. MethodsA secondary analysis of The National Immunization Survey – Teen data between 2016 and 2020 was conducted. Characteristics associated with initiation of the vaccine series was examined and used to evaluate UTD among initiators. All data were weighted. Associations between characteristics and HPV vaccine initiation were examined using Rao Scott chi-square tests and univariable logistic regression. Multivariable binary logistic regression models stratified by race/ethnicity calculated the strength of association between independent variables and odds of initiation and UTD among initiators. ResultsThe final sample size was 99,719 with 67,855 (68.1 %) initiating HPV vaccination. Among HPV vaccine initiators, Hispanic and black adolescents had lower odds of UTD. However, 9–10-year-old initiators had increased odds (aOR: 5.71; 95 %CI: 3.78–8.63) of UTD compared to 12-year-old initiators. Increased odds of UTD among initiators younger than 12 years were found across racial/ethnic groups. Flu vaccination was associated with decreased odds of UTD among white (aOR: 0.76; 95 %CI:0.65–0.88) and black adolescents (aOR: 0.67; 95 %CI: 0.46–0.96). ConclusionStrong recommendations to ensure patients are UTD on the HPV vaccine series are essential to improving UTD among all adolescents and follow-up should occur when administering other vaccines to reduce missed opportunities.

Immunogenicity of 2-Dose HPV Vaccine Series for Postpartum Women

Postpartum human papillomavirus (HPV) vaccination is a promising strategy to increase HPV vaccination uptake in the US, particularly for reaching vaccine-naive women and those who lack health insurance beyond the pregnancy period. However, completion of the 3-dose vaccine regimen is challenging. To evaluate the immunogenicity of a 2-dose postpartum HPV vaccination regimen (0 and 6 months) and assess whether it is noninferior to a 3-dose postpartum HPV vaccination regimen (0, 1-2, and 6 months) administered to historical controls. A noninferiority, open-label, nonrandomized immunogenicity trial was conducted from August 4, 2020, to June 23, 2022, of postpartum patients aged 15 to 45 years who delivered at 2 hospitals in Baltimore, Maryland. Historical controls were adolescents and young women aged 16 to 26 years. Two doses of the nonavalent HPV vaccine administered 6 months apart. The primary outcome was noninferiority (90% CI, lower bound >0.67) of the geometric mean titer (GMT) ratio for HPV-16 among postpartum women compared with historical controls. Secondary outcomes were noninferiority of GMT ratios for the other 8 HPV types and percentage seroconversion for each HPV type. As a noninferiority trial, the primary analysis used the per-protocol analysis. Of 225 enrolled participants, the mean (SD) age at baseline was 29.9 (6.8) years, and 171 (76.0%) were HPV-16 seronegative at baseline. Of these 171 participants, 129 (75.4%) received a second vaccine dose and completed the subsequent 4-week serologic measurements. Relative to historical controls, the HPV-16 GMT ratio was 2.29 (90% CI, 2.03-2.58). At month 7, HPV-16 GMT was higher after the 2-dose regimen (7213.1 mMU/mL [90% CI, 6245.0-8331.4 mMU/mL]) than among historic controls after the 3-dose regimen (3154.0 mMU/mL [90% CI, 2860.2-3478.0 mMU/mL]). Similarly, the lower bound of the 90% CI of the GMT ratio was above 1 for the 8 HPV types 6, 11, 18, 31, 33, 45, 52, and 58. A total of 118 of 134 women (88.1%) seroconverted for HPV-16 after the first dose; 4 weeks after the second dose, the seroconversion rate was 99% or greater for all HPV types. This study suggests that immunogenicity of a 2-dose HPV vaccination regimen given 6 months apart among postpartum women was noninferior to a 3-dose regimen among young historical controls. Most women seroconverted after the first dose of the 2-dose regimen. These results demonstrate that postpartum vaccination using a reduced schedule may be a promising strategy to increase HPV vaccine series completion. ClinicalTrials.gov Identifier: NCT04274153.

The association of caregiver attitudes, information sources, and trust with HPV vaccine initiation among adolescents

ABSTRACT This study described caregiver attitudes and the information sources they access about HPV vaccination for adolescents and determined their influence on human papillomavirus (HPV) vaccination initiation. An online survey was administered to 1,016 adults in July 2021. Participants were eligible if they were the caregiver of a child aged 9–17 residing in Mississippi, Arkansas, Tennessee, Missouri, and select counties in Southern Illinois. Multivariate logistic regression was used to estimate the association of caregiver attitudes and information sources with HPV vaccination. Information from doctors or healthcare providers (87.4%) and internet sources other than social media (31.0%) were the most used sources for HPV vaccine information. The highest proportion of caregivers trusted their doctor or healthcare providers (92.4%) and family or friends (68.5%) as sources of information. The HPV vaccine series was more likely to be initiated in children whose caregivers agreed that the vaccine is beneficial (AOR = 4.39, 95% CI = 2.05, 9.39), but less likely with caregivers who were concerned about side effects (AOR = 0.61, 95% CI = 0.42, 0.88) and who received HPV vaccination information from family or friends (AOR = 0.57, 95% CI = 0.35, 0.93). This study found that caregivers’ attitudes, information sources, and trust in those sources were associated with their adolescent’s HPV vaccination status. These findings highlight the need to address attitudes and information sources and suggest that tailored interventions considering these factors could increase HPV vaccination rates.

Impact of COVID-19 pandemic and vaccine perceptions on HPV vaccine hesitancy

ObjectiveThis study evaluated the impact of the COVID-19 pandemic and vaccine perceptions on Human Papillomavirus (HPV) vaccine hesitancy. Secondary endpoints included comparing COVID-19 and HPV vaccination trends regarding time, community of residence, and unmet social needs. MethodsThis was a survey-based, cross-sectional study that included 101 participants who were recruited through the Wyandotte County Public Health Department. Participants were eligible for inclusion in this study if they were a parent/guardian of one or more children aged 13 to 17; English- or Spanish-speaking. This study took place in Wyandotte County, Kansas. Descriptive statistics and chi-square analyses were utilized. ResultsThere was no difference in completion of COVID-19 and HPV vaccines (p = 0.0975). Significantly more individuals started and did not finish the HPV vaccine series compared to the COVID-19 vaccine series (p = 0.0004). Most participants indicated their opinion on the HPV vaccine had not changed due to the pandemic (71.3 %). Participants who felt familiar with HPV had higher rates of HPV vaccine completion. While 77 % of participants felt extremely or moderately familiar with HPV, 61.4 % were unaware of its association with oropharyngeal cancer. ConclusionThere was minimal change in parents' perception of the HPV vaccine due to the COVID-19 pandemic despite decreased rates of vaccination during this time. HPV vaccine series completion was significantly lower than COVID-19 vaccine series completion, highlighting a need to improve HPV vaccine completion counseling. Additionally, patient education should address the knowledge gap discovered regarding the link between HPV infection and oropharyngeal cancer.

1172. Compliance with Human Papillomavirus Vaccination At The HIV Outpatient Program in New Orleans, Louisiana

Abstract Background Guidelines recommend the human papillomavirus (HPV) vaccine for all adults through age 26, shared clinical decision-making for those aged 27 through 45 years who are inadequately vaccinated, and for all people with HIV up to age 45 years. The intent of this study is to evaluate HPV vaccination rates at the HIV Outpatient Program (HOP) at University Medical Center in New Orleans. Methods Immunization records from patients aged 18 through 45 years attending a physician visit in the LSU Infectious Diseases fellows’ HIV primary care clinic at HOP in 2022 were reviewed. The purpose of this project was to assess compliance with HPV vaccination recommendations among the infectious diseases fellows. Results Among patients under age 27, 15 of 21 visits (71%) had completed HPV vaccines series. 4 visits (19%) had incomplete status and 2 visits (10%) did not have any HPV vaccines record. Among patients aged 27 through 45 years, 73 of 194 visits (38%) had completed HPV vaccines series. 34 visits (18%) had partial vaccination records and 87 visits (45%) had no records. Conclusion Vaccination compliance among the LSU ID fellows was less than ideal, only 71% of visits for patient aged up to 27 years attending LSU ID fellows’ clinic had completed HPV vaccine series, compared to the Health People 2020 recommendation of 80%. Only 38% of visits for patients aged 27 through 45 years are fully vaccinated with HPV vaccines. Patients in this age group are often labeled “aged out” for HPV vaccines by health maintenance reminders however, due to having HIV, they are still eligible and should be vaccinated. These results led to the institution of quality improvement project to address HPV vaccinations. This intervention will focus on educating all HOP providers about the vaccination recommendations and updating the health maintenance care gaps reminder in the electronic medical record. Disclosures All Authors: No reported disclosures

Exploring Delivery of Adolescent Preventive Health Services During the COVID-19 Pandemic: Perceptions and Experiences Shared by Healthcare Professionals

Abstract Background While unmitigated vaccine hesitancy was already growing before the emergence of COVID-19, the global pandemic has introduced additional challenges to the immunization sector. Despite the benefits, routine preventive care was forestalled by challenges related to pandemic lockdowns/quarantine, parental reluctance to seek preventative services, poor access to healthcare, loss of income and/or health insurance, and the inability of children under 12 to be immunized against the coronavirus. Considering the potential impacts caused by the pandemic’s disruption of adolescent preventative care services, we explored the experiences of adolescent healthcare providers in Tennessee and Georgia in providing care throughout the COVID-19 pandemic. Methods A series of in-depth qualitative interviews were conducted between December 2020 and May 2021 via the video conferencing platform, Zoom, among a diverse group of adolescent healthcare providers (n=16) representing 5 healthcare practices located within the southeastern states of Georgia and Tennessee. Audio recordings were transcribed verbatim and analyzed using a rapid qualitative analysis framework, guided by the grounded theory and inductive approach. Results Preventive adolescent services were adversely impacted by the COVID-19 pandemic at all participating practices. Participants highlighted an initial decrease in patients due to the pandemic, despite the implementation of protective measures such as an increase in sanitation measures, hand washing, separation of sick and wellness visits, mask mandates, and telehealth/video conferencing opportunities. While practices continued to distribute educational materials, many removed material from their waiting rooms due to sanitary concerns related to COVID-19. Participants reported that patient-provider communications; effective use of presumptive languaging; periodic reminders/recall messages; provider’s personal recommendation on vaccine safety/efficacy; early initiation of human papillomavirus (HPV) vaccination series at 9 years; community partnerships with health navigators/vaccine champions/vaccine advocates; use of standardized forms/prewritten scripts/standard operating protocols for patient-provider interactions; and vaccine promotion through social media, brochures/posters/pamphlets, as well as outreach to schools and churches, served as facilitators to adolescent HPV vaccine uptake. Conclusions By exploring the perceptions and experiences of adolescent healthcare providers, our research identified key factors influencing adolescent vaccination uptake and its relatedness to the COVID-19 pandemic. We argue our findings support and encourage the development of personalized patient-provider communications, trusting relationships, effective use of presumptive languaging, and counteraction of misinformation as solutions to suboptimal preventative services and vaccination coverage rates. Implementation of these comprehensive strategies could not only ameliorate routine adolescent vaccination uptake but could also aid in the expansion of COVID-19 vaccine acceptance on a sizable scale.

Human Papillomavirus Vaccine Completion by 13: A Quality Improvement Initiative in a Large Primary Care Network

ObjectiveFewer than 40% of U.S. children complete the human papillomavirus (HPV) vaccine series before their 13th birthday. In our large pediatric primary care network, HPV vaccine completion rate by age 13 was 30%. We hypothesized that a phased quality improvement (QI) initiative would increase rates of HPV vaccine completion by age 13 across our network. MethodsThis QI initiative was conducted in a network of 30 practices located across two states, in urban and suburban settings, consisting of teaching and non-teaching clinics, and ranging in size from three to 50 providers per office. We used a phased approach incorporating multicomponent network-wide and iterative practice-specific interventions. Key interventions included: updating clinical decision support to default order HPV vaccine due at preventive visits starting at age nine instead of 11, data audit and feedback to providers and practices, encouraging use of a strong provider recommendation, and standing orders. ResultsFrom April 2019 to October 2022, HPV vaccine completion by age 13 across our network increased from 30% to 55% and met criteria for special cause variation on statistical process control charts. A gap in median HPV vaccine completion by age 13 between patients with public insurance and patients with private or commercial insurance decreased from 9% to 1%. ConclusionA QI initiative was associated with a sustained increase in HPV vaccine series completion by age 13 and reduced variation in care across a large network of 30 primary care practices.

The roles of Human Papillomavirus (HPV) test awareness and knowledge in HPV vaccination initiation and completion among college students in the Deep South of the United States: applying the Andersen’s Behavioral Model

ABSTRACT Human papillomavirus (HPV) has the highest prevalence of all sexually transmitted infections in the United States (U.S.). Despite the effectiveness in preventing HPV-related cancers, HPV vaccination rates were still low among young adults. Thus, this study aimed to (1) investigate HPV vaccination initiation and completion rates among college students, (2) examine relevant factors associated with HPV vaccine initiation and completion. A convenient sample of 327 college students was recruited from universities in the Deep South of the U.S. via online surveys. Logistic regressions were conducted to examine factors associated with HPV vaccination initiation and completion. About 54% of participants in the current study initiated HPV vaccination, and most of the participants who initiated the vaccination completed the series (52%). Participants who were female (odds ratio [OR] = 3.01, confidence interval [CI] = 1.38 to 6.58; OR = 2.28, CI = 1.07 to 4.85), aware of the HPV tests (OR = 16.53, CI = 5.60 to 48.83; OR = 7.36, CI = 2.99 to 18.13), and aware that ‘men should have HPV vaccination’ (OR = 2.33, CI = 1.07 to 5.09; OR = 3.27, CI = 1.50 to 7.12) were more likely to initiate the HPV vaccination and complete the vaccine series. The finding that only half of the students initiated and completed the HPV vaccine series indicates that further studies and intervention strategies are needed. Particular attention should be focused on college student populations who are male and with little HPV health knowledge.

Vaccination Coverage Among Adolescents Aged 13-17 Years - National Immunization Survey-Teen, United States, 2022.

Three vaccines are routinely recommended for adolescents to prevent pertussis, meningococcal disease, and cancers caused by human papillomavirus (HPV). CDC analyzed data from the 2022 National Immunization Survey-Teen for 16,043 adolescents aged 13-17 years to assess vaccination coverage. Birth cohort analyses were conducted to assess trends in vaccination coverage by age 13 years (i.e., before the 13th birthday) and by age 14 years (i.e., before the 14th birthday) among adolescents who were due for routine vaccination before and during the COVID-19 pandemic. Cross-sectional analysis was used to assess coverage estimates among adolescents aged 13-17 years. In 2022, vaccination coverage by age 14 years among adolescents born in 2008 continued to lag that of earlier birth cohorts and varied by sociodemographic factors and access to health care compared with coverage among earlier birth cohorts. Vaccination coverage by age 13 years among adolescents born in 2009 was similar to coverage estimates obtained before the COVID-19 pandemic. Among all adolescents aged 13-17 years, 2022 vaccination coverage levels did not differ from 2021 levels; however, initiation of the HPV vaccination series decreased among those who were insured by Medicaid. Coverage with ≥1 dose of tetanus, diphtheria, and acellular pertussis vaccine and ≥1 dose meningococcal conjugate vaccine was high and stable (around 90%). Providers should review adolescent vaccination records, especially among those born in 2008 and those in populations eligible for the Vaccines for Children program, to ensure adolescents are up to date with all recommended vaccines.

Communication Interactions, Needs, and Preferences During Clinical Encounters of African American Parent-Child Dyads.

Human papillomavirus (HPV) vaccination rates remain suboptimal among African American adolescents. Although provider recommendations during clinical encounters are believed to be highly effective in increasing uptake and series completion, little has been reported about parent-child perspectives on the counseling received during these encounters. Among African American parent-child dyads, we sought to explore and compare interactions, needs, and preferences during clinical encounters by child's HPV vaccination status. We applied a qualitative, phenomenological study design to conduct semi-structured interviews with African American parent-child dyads representing children who were unvaccinated (n = 10), had initiated but not completed (n = 11), or had completed the HPV vaccine series (n = 9). Using iterative, inductive-deductive thematic analysis, five themes were generated: (1) parents' attitudes varied about the HPV vaccine but were mostly positive for vaccines in general; (2) patient-parent-provider clinical encounters from the parent perspective; (3) patient-parent-provider clinical encounters from the child perspective; (4) methods of distribution of supplemental HPV information; and (5) communication desired on HPV vaccination by parents and children. Parents stating they received a provider's recommendation increased by vaccination status (unvaccinated: 6 out of 10; initiated: 7 out of 11; completed: 9 out of 9). Most parents and children were not satisfied with provider communication on the HPV vaccine and used supplemental materials to inform decision-making. Ongoing communication on the HPV vaccine was requested even post-vaccination of the child. During clinical encounters, children and parental messaging needs are similar yet dissimilar. We offer communication strategies and messaging that can be used for African American parent-child dyads by child HPV vaccination status during a clinical encounter.

Racial, Ethnic, and Gender Differences in the Timing of Initiating the HPV Vaccine in the UnitedStates: the Case of Southeast Asian Americans.

Despite the availability of the human papillomavirus (HPV) vaccine, non-Latinx (NL) Southeast Asian Americans have the highest incidence of HPV-associated cervical cancer in the US. Little is known about NL-Southeast Asian Americans' HPV vaccination coverage due to being categorized under the "Asian American" monolith. Therefore, this study uses restricted data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) to disaggregate NL-Southeast Asian Americans and compare this population's age-specific probabilities of initiating HPV vaccinations to two Asian American subgroups (NL-East Asian and NL-South Asian Americans) and NL-White, NL-Black, and Latinx Americans. Multinomial logistic regression models examine the differences in the timing of initiating the HPV vaccine series, late (ages 13-26) or never, relative to on-time vaccination (by age 12). NL-Southeast Asian Americans are significantly more likely to never vaccinate and to vaccinate late than NL-White, NL-Black, and Latinx Americans, relative to on-time vaccination. NL-Southeast Asian American boys/men are significantly more likely to never initiate the HPV vaccine than Latinx boys/men, relative to on-time vaccination. NL-Southeast Asian American girls/women are significantly more likely to never vaccinate and vaccinate late than NL-White, NL-Black, and Latinx girls/women, relative to on-time vaccination. There are significant gender differences in uptake among all racial and ethnic groups, except among NL-Southeast and NL-East Asian Americans. Disaggregated data on NL-Southeast Asian Americans helps scholars and public health officials uncover health disparities and improve health interventions. Targeted HPV vaccine promotion and services for this population are needed to mitigate current and future health disparities and promote health equity.

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 &amp; 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.

In the United States (US), half of new human papillomavirus (HPV) infections occur among young people aged 15-24years. 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. Responses to an online Qualtrics survey from 926 parents of children aged 9-17years 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. Of 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 9-17years 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 9-12years), 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). Adolescent 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.