Series Completion Research Articles

Factors Affecting Human Papillomavirus Vaccine Trends in the United States of America.

Background Routine immunization of both girls and boys starting from nine years of age with the human papillomavirus (HPV) vaccine is the current recommendation. The objective of this retrospective study using National Health and Nutrition Examination Survey data was to evaluate the influence of sociodemographic factors on the series initiation and completion of the HPV vaccine from 2011 to 2020. Methodology The chi-square test was used to examine the statistical significance of the association between categorical variables and receipt of the HPV vaccine. The Cochran-Armitage test for trend was employed to assess the statistical significance of temporal trends in risk factors associated with rates of HPV vaccination. These trends were further quantified by a significant rate ratio by comparing them against the most recent survey years. Results HPV vaccine uptake was higher in the 9-14-year age group across survey years and had increased for both males and females over that time. The first dose of the HPV vaccine wasmost likely to be received by the11-18-year age group. In the most recent survey of 2017-2020, the highest number of vaccination series completion was achieved for Gardasil®. Conclusions Improved physician efforts and strategies to vaccinate males, low socioeconomic strata patients, and ethnic minorities in more numbers are needed.

Demographic Disparities in Mpox Vaccination Series Completion, by Route of Vaccine Administration - California, August 9, 2022-March 31, 2023.

In August 2022, the Food and Drug Administration authorized JYNNEOS vaccine (modified vaccinia Ankara vaccine, Bavarian Nordic), a 2-dose series used for the prevention of Monkeypox virus infection, to be administered via a dose-sparing intradermal route, in addition to the previously authorized subcutaneous route. The California Department of Public Health investigated whether demographic disparities in vaccination series completion varied by route of administration of the recipient's first dose. Among California residents who received their first dose during August 9, 2022-March 31, 2023, a total of 59.8% received a second dose. Series completion was highest among non-Hispanic White persons (64.1%), persons aged ≥65 years (72.6%), and adults with male sex assignment at birth (62.1%); series completion was lowest among non-Hispanic Black or African American persons (51.3%), persons aged 18-24 years (42.9%), and adults assigned female sex at birth (42.8%). When the first dose was received by subcutaneous administration, overall series completion was 58.8% compared with 60.2% when the first dose was administered intradermally. Odds of series completion across all race and ethnicity groups, persons aged 18-64 years, community health conditions, and persons assigned male sex at birth were not greater when the first dose was administered subcutaneously compared with intradermally. Intradermal use of JYNNEOS vaccine did not lower overall 2-dose series completion rates. Continued efforts are needed to ensure persons at risk for Monkeypox virus infection receive both recommended doses.

Failure to Complete Multidose Vaccine Series in Early Childhood.

Most early childhood immunizations require 3 to 4 doses to achieve optimal protection. Our objective was to identify factors associated with starting but not completing multidose vaccine series. Using 2019 National Immunization Survey-Child data, US children ages 19 to 35 months were classified in 1 of 3 vaccination patterns: (1) completed the combined 7-vaccine series, (2) did not initiate ≥1 of the 7 vaccine series, or (3) initiated all series, but did not complete ≥1 multidose series. Associations between sociodemographic factors and vaccination pattern were evaluated using multivariable log-linked binomial regression. Analyses accounted for the survey's stratified design and complex weighting. Among 16 365 children, 72.9% completed the combined 7-vaccine series, 9.9% did not initiate ≥1 series, and 17.2% initiated, but did not complete ≥1 multidose series. Approximately 8.4% of children needed only 1 additional vaccine dose from 1 of the 5 multidose series to complete the combined 7-vaccine series. The strongest associations with starting but not completing multidose vaccine series were moving across state lines (adjusted prevalence ratio [aPR] = 1.45, 95% confidence interval [CI]: 1.18-1.79), number of children in the household (2 to 3: aPR = 1.29, 95% CI: 1.05-1.58; 4 or more: aPR = 1.68, 95% CI: 1.30-2.18), and lack of insurance coverage (aPR = 2.03, 95% CI: 1.42-2.91). More than 1 in 6 US children initiated but did not complete all doses in multidose vaccine series, suggesting children experienced structural barriers to vaccination. Increased focus on strategies to encourage multidose series completion is needed to optimize protection from preventable diseases and achieve vaccination coverage goals.

Disparities in child and adolescent COVID-19 vaccination coverage and parental intent toward vaccinations for their children and adolescents

Introduction Despite recommendations for COVID-19 primary series completion and booster doses for children and adolescents, coverage has been less than optimal, particularly in some subpopulations. This study explored disparities in childhood/adolescent COVID-19 vaccination, parental intent to vaccinate their children and adolescents, and reasons for non-vaccination in the US. Methods Using the U.S. Census Bureau’s Household Pulse Survey (HPS), we analyzed households with children aged <18 years using data collected from September 14 to November 14, 2022 (n = 44,929). Child and adolescent COVID-19 vaccination coverage (≥1 dose, completed primary series, and booster vaccination) and parental intentions toward vaccination were assessed by sociodemographic characteristics. Factors associated with child and adolescent vaccination coverage were examined using multivariable regression models. Reasons for non-vaccination were assessed overall, by the child’s age group and respondent’s age group. Results Overall, approximately half (50.1%) of children aged < 18 years were vaccinated against COVID-19 (≥1 dose). Completed primary series vaccination was 44.2% among all children aged <18 years. By age group, completed primary series was 13.2% among children <5 years, 43.9% among children 5–11 years, and 63.3% among adolescents 12–17 years. Booster vaccination among those who completed the primary series was 39.1% among children 5–11 years and 55.3% among adolescents 12–17 years. Vaccination coverage differed by race/ethnicity, educational attainment, household income, region, parental COVID-19 vaccination status, prior COVID-19 diagnosis, child’s age group, and parental age group. Parental reluctance was highest for children aged <5 years (46.8%). Main reasons for non-vaccination among reluctant parents were concerns about side effects (53.3%), lack of trust in COVID-19 vaccines (48.7%), and the belief that children do not need a COVID-19 vaccine (38.8%). Conclusion Disparities in COVID-19 vaccination coverage among children and adolescents continue to exist. Further efforts are needed to increase COVID-19 primary series and booster vaccination and parental confidence in vaccines.

Verbal but not visual-spatial working memory contributes to complex arithmetic calculation.

The contribution of working memory to mathematics has been extensively studied. It has been proposed that verbal working memory (VWM) and visual-spatial working memory (VSWM) have distinct contributions, but results have been inconclusive. Here, we hypothesized that VWM and VSWM contribute differentially to separate sub-domains of mathematics. To test this hypothesis, we enrolled 199 primary school students and measured their VWM and VSWM with number/letter/matrix backward span tasks, and tested mathematics performance with simple subtraction, complex subtraction, multi-step calculation and number series completion, while controlling for several aspects of cognition. We found that while letter backward span had a significant contribution to complex subtraction, multi-step computation and number series completion, number backward span only had a significant contribution to multi-step computation, and matrix span had no effect on any math task. These results suggest that only VWM associated with complex mathematics, which might reflect verbal rehearsal. In contrast, VSWM does not appear to associated with mathematics.

State Policy Removing the Personal Belief Exemption for Measles, Mumps, and Rubella (MMR) School Immunization Requirement, Washington State, 2014-2022.

Objectives. To assess the impact of Washington State's 2019 Engrossed House Bill (EHB) 1638-which removed measles, mumps, and rubella (MMR) personal belief exemptions-on MMR vaccine series completion and exemption rates in K-12 students. Methods. We used interrupted time-series analyses to examine changes in MMR vaccine series completion rates before and after EHB 1638 was passed and the χ2 test for differences in exemption rates. Results. EHB 1638 implementation was associated with a 5.4% relative increase in kindergarten MMR vaccine series completion rates (95% confidence interval = 3.8%, 7.1%; P ≤ .001), and results were similar with Oregon as a control state (no change observed in Oregon; P = .68). MMR exemptions overall decreased 41% (from 3.1% in 2018-2019 to 1.8% in 2019-2020; P ≤ .001), and religious exemptions increased 367% (from 0.3% to 1.4%; P ≤ .001). Conclusions. EHB 1638 was associated with an increase in MMR vaccine series completion rates and a decrease in any MMR exemption. However, effects were partially offset by an increase in religious exemption rates. Public Health Implications. Removal of personal belief exemptions for the MMR immunization requirement only may be an effective approach to increase MMR vaccine coverage rates statewide and among underimmunized communities. (Am J Public Health. 2023;113(7):795-804. https://doi.org/10.2105/AJPH.2023.307285).

A systematic review of interventions to promote HPV vaccination globally

BackgroundDespite the human papillomavirus (HPV) vaccine being a safe, effective cancer prevention method, its uptake is suboptimal in the United States (U.S.). Previous research has found a variety of intervention strategies (environmental and behavioral) to increase its uptake. The purpose of the study is to systematically review the literature on interventions that promote HPV vaccination from 2015 to 2020.MethodsWe updated a systematic review of interventions to promote HPV vaccine uptake globally. We ran keyword searches in six bibliographic databases. Target audience, design, level of intervention, components and outcomes were abstracted from the full-text articles in Excel databases.ResultsOf the 79 articles, most were conducted in the U.S. (72.2%) and in clinical (40.5%) or school settings (32.9%), and were directed at a single level (76.3%) of the socio-ecological model. Related to the intervention type, most were informational (n = 25, 31.6%) or patient-targeted decision support (n = 23, 29.1%). About 24% were multi-level interventions, with 16 (88.9%) combining two levels. Twenty-seven (33.8%) reported using theory in intervention development. Of those reporting HPV vaccine outcomes, post-intervention vaccine initiation ranged from 5% to 99.2%, while series completion ranged from 6.8% to 93.0%. Facilitators to implementation were the use of patient navigators and user-friendly resources, while barriers included costs, time to implement and difficulties of integrating interventions into the organizational workflow.ConclusionsThere is a strong need to expand the implementation of HPV-vaccine promotion interventions beyond education alone and at a single level of intervention. Development and evaluation of effective strategies and multi-level interventions may increase the uptake of the HPV vaccine among adolescents and young adults.

Concerns related to the interactions between COVID-19 vaccination and cancer/cancer treatment were barriers to complete primary vaccination series among Chinese cancer patients: A multicentre cross-sectional survey

ABSTRACT COVID-19 vaccination is effective for cancer patients without safety concerns. However, COVID-19 vaccination hesitancy is common among cancer patients. This study investigated factors affecting primary COVID-19 vaccination series completion rate among cancer patients in China. A multicentre cross-sectional study was conducted in four Chinese cities in different geographic regions between May and June 2022. A total of 893 cancer inpatients provided written informed consent and completed the study. Logistic regression models were fitted. Among the participants, 58.8% completed the primary COVID-19 vaccination series. After adjusting for background characteristics, concerns about interactions between COVID-19 vaccination and cancers/cancer treatment (adjusted odds ratios [AOR]: 0.97, 95%CI: 0.94, 0.99) were associated with lower completion of primary vaccination series. In addition, perceived higher risk of COVID-19 infection comparing to people without cancers (AOR: 0.46, 95%CI: 0.24, 0.88), perceived a high chance of having severe consequences of COVID-19 infection (AOR: 0.68, 95%CI: 0.51, 0.91) were also associated with lower completion rate. Being suggested by significant others (AOR: 1.32, 95%CI: 1.23, 1.41) and perceived higher self-efficacy to receive COVID-19 vaccination (AOR: 1.48, 95%CI: 1.31, 1.67) were positively associated with the dependent variable. Completion rate of primary COVID-19 vaccination series was low among Chinese cancer patients. Given the large population size and their vulnerability, this group urgently needs to increase COVID-19 vaccination coverage. Removing concerns about interactions between COVID-19 vaccination and cancers, using fear appeal approach, involving significant others, and facilitating patients to make a plan to receive COVID-19 vaccination might be useful strategies.

HPV Vaccination among College Students in the South: The Role of HPV Knowledge on Vaccine Initiation and Completion.

The purpose of this study was to examine factors related to HPV vaccination initiation and completion, especially the role of health knowledge, among college students in a southern state. College students ages 17-45 (n=1,708) were analyzed in this study. Primary outcomes were HPV vaccine series initiation and completion; binary logistic regressions were performed to identify associated factors. Among total participants, students who were aware that HPV could be transmitted even without symptoms were less likely to initiate HPV vaccination. However, among students who have initiated the vaccine series, those who were aware that HPV could be transmitted without symptoms and that men should receive the HPV vaccine were more likely to complete the vaccine series. Other significant variables included age, gender, race, and international student status. Future studies are needed to investigate students' concerns regarding initiating HPV vaccination and how to effectively motivate students to initiate and complete the HPV vaccine series.

HSD16 Impact of Provider Nudges on Herpes Zoster Vaccine Series Completion during the COVID-19 Pandemic in the United States

To determine the impact of a pharmacy-based, clinical decision support (CDS) tool on herpes zoster (HZ) vaccine series completion during the initial months of the COVID-19 pandemic across the US. In partnership with Kroger Health, a pharmacy CDS tool alerted staff of patients due for their second HZ vaccine dose, which had been accompanied previously by a timed text message. Once operations changed due to COVID-19, the system limited outreach to only patients visiting the pharmacy. Primary outcomes included the proportion of patients receiving both doses within a Kroger-owned pharmacy (n=2,293) and the number of days between doses, both within and across two 32-week periods before and after the pandemic hit the US. Generalized estimating equation-based (GEE) logistic and linear regression models determined differences in completion rates and time to completion. During the observation period, 38,937 adults received at least one HZ vaccine dose, with 77.2% receiving both doses. Patients engaged by the CDS tool achieved 80.5% dose completion, versus 65.4% of those not intervened (p<0.0001), which was lower than in the period immediately before the pandemic (85.8%, p<0.0001). The dosing window averaged 119.4 days (SD: 26.91), which was the longest timeframe between doses since the HZ vaccine was launched and nearly one month longer than before the pandemic (93.0 days [SD: 28.02], p<0.0001). The odds of dose completion increased in areas of higher health literacy (OR: 1.01; 95% CI: 1.007-1.014), but decreased in areas of higher poverty (OR: 0.992; 95% CI: 0.988-0.995). Time to completion was slightly shorter (B=-0.04, p<0.05) in areas of higher health literacy. Despite changes in clinical processes, a nationwide community pharmacy was successful in completing HZ vaccine dose series for adults during the pandemic, suggesting that processes in community pharmacies can protect staff while remaining committed to providing preventive health services during public health crises.

Early Initiation of HPV Vaccine Improves Timely Series Completion

Early Initiation of HPV Vaccine Improves Timely Series Completion

Factors associated with receipt of mRNA-1273 vaccine at a United States national retail pharmacy during the COVID-19 pandemic

IntroductionThe emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prompted accelerated vaccine development of novel messenger RNA (mRNA)-based vaccines by Moderna and Pfizer, which received FDA Emergency Use Authorization in December 2020. The purpose of this study was to examine trends in primary series administration and multi-dose completion rates with Moderna’s mRNA-1273 vaccine administered at a United States retail pharmacy. MethodsWalgreens pharmacy data were joined to publicly available data sets to examine trends in mRNA-1273 primary series and multi-dose completion across patient race/ethnicity, age, gender, distance to first vaccination, and community characteristics. Eligible patients received their first dose of mRNA-1273 administered by Walgreens between December 18, 2020 and February 28, 2022. Variables significantly associated with on-time second dose (all patients) and third dose (immunocompromised patients) in univariate analyses were included in linear regression models. A subset of patients in selected states were studied to identify differences in early and late vaccine adoption. ResultsPatients (N = 4,870,915) who received ≥ 1 dose of mRNA-1273 were 57.0% White, 52.6% female, and averaged 49.4 years old. Approximately 85% of patients received a second dose during the study period. Factors associated with on-time second dose administration included older age, race/ethnicity, traveling ≤ 10 miles for the first dose, higher community-level health insurance, and residing in areas with low social vulnerability. Only 51.0% of immunocompromised patients received the third dose as recommended. Factors associated with third dose administration included older age, race/ethnicity, and small-town residence. Early adopters accounted for 60.6% of patients. Factors associated with early adoption included older age, race/ethnicity, and metropolitan residence. ConclusionOver 80% of patients received their on-time second dose of mRNA-1273 vaccine per CDC recommendations. Patient demographics and community characteristics were associated with vaccine receipt and series completion. Novel approaches to facilitate series completion during a pandemic should be further studied.

Time series outlier removal and imputing methods based on Colombian weather stations data

The time data series of weather stations are a source of information for floods. The study of the previous wintertime series allows knowing the behavior of the variables and the result that will be applied to analysis and simulation models that feed variables such as flow and level of a study area. One of the most common problems is the acquisition and transmission of data from weather stations due to atypical values and lost data; this generates difficulties in the simulation process. Consequently, it is necessary to propose a numerical strategy to solve this problem. The data source for this study is a real database where these problems are presented with different variables of weather. This study is based on comparing three methods of time series analysis to evaluate a multivariable process offline. For the development of the study, we applied a method based on the discrete Fourier transform (DFT), and we contrasted it with methods such as the average and linear regression without uncertainty parameters to complete missing data. The proposed methodology entails statistical values, outlier detection, and the application of the DFT. The application of DFT allows the time series completion, based on its ability to manage various gap sizes and replace missing values. In sum, DFT led to low error percentages for all the time series (1% average). This percentage reflects what would have likely been the shape or pattern of the time series behavior in the absence of misleading outliers and missing data.

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.

The involvement of the semantic neural network in rule identification of mathematical processing

The role of the visuospatial network in mathematical processing has been established, but the involvement of the semantic network in mathematical processing is still poorly understood. The current study utilized a number series completion paradigm with the event-related potential (ERP) technique to examine whether the semantic network supports mathematical processing and to find the corresponding spatiotemporal neural marker. In total, 32 right-handed undergraduate students were recruited and asked to complete the number series completion as well as the arithmetical computation task in which numbers were presented in sequence. The event-related potential and multi-voxel pattern analysis showed that the rule identification process involves more semantic processing when compared with the arithmetical computation processes, and it elicited higher amplitudes for the late negative component (LNC) in left frontal and temporal lobes. These results demonstrated that the semantic network supports the rule identification in mathematical processing, with the LNC acting as the neural marker.

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 753: HPV vaccine uptake in survivors of childhood and adolescent and young adult (AYA) cancer

Abstract Introduction: There will be an estimated 110,000 children and adolescents’ cancer survivors in the United States (US) in 2022. Previous studies have argued for the establishment of a specialized adolescent and young adult (AYA) oncology service to better serve their needs. Studies have demonstrated that survivors of childhood and AYA cancers remain at higher risk of developing second primary cancers over their lifetime. AYA cancer survivors are a growing part of the population and will benefit from HPV vaccination. Documenting HPV vaccine uptake among cancer survivors will facilitate interventions to improve vaccination rates in this population. Despite evidence supporting the efficacy of HPV vaccination, AYA vaccination rates are low. Furthermore, studies assessing HPV vaccination coverage in survivors of AYA cancer are lacking. Therefore, we assessed HPV vaccine initiation and completion between survivors of AYA cancer and respondents without a cancer diagnosis among 18-35-year-old in the US. Methods: We analyzed data from the 2017-2018 National Health Interview Survey, an annual cross-sectional national survey that provides information on the health of the noninstitutionalized US population. The outcome variables were HPV vaccine initiation (receipt of ≥1 dose) and completion (receipt of ≥3 doses). Exposure was cancer survivorship (AYA cancer survivors [respondents who were diagnosed with cancer as a child, adolescent, or young adult] vs. respondents without a cancer diagnosis). Weighted multivariable logistic regression models were used to examine the association between cancer survivorship and HPV vaccine initiation and completion, controlling for socioeconomic and healthcare access related factors. Results: A total of 2,942 respondents were included in the study, of which 242 (7.1%) were AYA cancer survivors. HPV vaccine initiation (22.5%) and completion (16.3%) among AYA cancer survivors were comparable to respondents without cancer diagnosis (initiation: 25.5%, completion: 15.3%). In the adjusted analyses, there were no significant differences in HPV vaccine initiation (P=0.6770) or completion (P=0.2001) between AYA cancer survivors and respondents without cancer diagnosis. Conclusions: HPV vaccine series initiation and completion were comparably low among AYA cancer survivors and respondents without a cancer diagnosis in our study. Low uptake of HPV vaccine among AYA cancer survivors is a more notable public health concern given their heightened immunocompromised status and elevated risk for second primary cancers. There is a need for primary care and oncology providers to encourage HPV vaccination and raise awareness of its crucial role among families of AYA cancer survivors. Citation Format: Mrudula Nair, Chaitali S. Dagli, Betelihem B. Tobo, Samantha H. Tam, Nada Al-Antary, Nosayaba Osazuwa-Peters, Eric Adjei Boakye. HPV vaccine uptake in survivors of childhood and adolescent and young adult (AYA) cancer [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 753.

Geographic proximity to immunization providers and vaccine series completion among children ages 0-24months.

In the U.S., vaccination coverage is lower in rural versus urban areas. Spatial accessibility to immunization services has been a suspected risk factor for undervaccination in rural children. Our objective was to identify whether geographic factors, including driving distance to immunization providers, were associated with completion of recommended childhood vaccinations. We analyzed records from Montana's immunization information system for children born 2015-2017. Using geolocated address data, we calculated distance in road miles from children's residences to the nearest immunization provider. A multivariable log-linked binomial mixed model was used to identify factors associated with completion of the combined 7-vaccine series by age 24months. Among 26,085 children, 16,503 (63.3%) completed the combined 7-vaccine series by age 24months. Distance to the nearest immunization provider ranged from 0 to 81.0 miles (median=1.7; IQR=3.2), with the majority (92.1%) of children living within 10 miles of a provider. Long distances (>10 miles) to providers had modest associations with not completing the combined 7-vaccine series (adjusted prevalence ratio [aPR]: 0.97, 95% confidence interval [CI]: 0.96-0.99). After adjustment for other factors, children living in rural areas (measured by rural-urban commuting area) were significantly less likely to have completed the combined 7-vaccine series than children in metropolitan areas (aPR: 0.88, 95% CI: 0.85-0.92). Long travel distances do not appear to be a major barrier to childhood vaccination in Montana. Other challenges, including limited resources for clinic-based strategies to promote timely vaccination and parental vaccine hesitancy, may have greater influence on rural childhood vaccination.

Human Papillomavirus Vaccination and Cervical Cancer Risk

ABSTRACT The progression of high-risk human papillomavirus (hrHPV) to cervical cancer is well characterized, and risk factors for hrHPV including genetic predisposition, hormonal factors, host immune response, and cigarette smoking are well documented. Prevention of cervical cancer primarily relies on preventing hrHPV infection through vaccination, as well as treatment of precancerous lesions (high-grade cervical intraepithelial neoplasia [CIN2/3] or adenocarcinoma in situ [ACIS]). Bivalent, quadrivalent, and nonavalent HPV vaccines are prequalified by the World Health Organization (WHO) and widely licensed; however, less than 25% of low-income countries have HPV vaccination as part of their national immunization schedules. The WHO set a target for 194 countries to adopt HPV vaccination by 2030, and this article summarizes clinical data on the efficacy and effectiveness of HPV vaccination, its potential impact on incidence of invasive cervical squamous cell carcinoma (ICC), and strategies to increase access to and uptake of vaccination. Large online databases were searched for randomized control trials and population-based cohort studies in which HPV vaccination and pathologic diagnosis were documented in the data set. Several large-scale studies including a Cochrane review of 73,428 participants and a meta-analysis of more than 60 million, and data from National registries in Sweden, Japan, and the United Kingdom demonstrated that HPV vaccination is safe and leads to prevention of cervical precancer. In April 2022, the WHO updated its recommendation to be 1 or 2 doses for girls aged 9–14 years; 1 or 2 doses for girls aged 15–20 years; and 2 doses separated by 6 months for women older than 21. Eight of every 10 cases of IIC occur in low- and middle-income countries (LMICs), and ICC is the leading cause of death from cancer among women in sub-Saharan Africa. Disparities among these countries are driven by inequity in access to prevention and treatment of cancer. Global HPV vaccination coverage for girls is approximately 18% for a first dose and 13% for series completion. On the supply side, barriers to vaccination include prohibitive cost of vaccines for many LMICs and the requirement for refrigeration of all licensed vaccines. Promisingly, a new quadrivalent prophylactic HPV vaccine is becoming available in 2023 in India that may significantly reduce the cost of vaccine doses and may not require refrigeration. On the demand side, misinformation, cultural views on sex, and mistrust of the medical system are major barriers. According to data from 37 registries in 20 countries, without changing the rate of HPV vaccination or cervical cancer screening, the global burden will increase from an estimated 600,000 in 2020 to 1.3 million in 2069. Models demonstrate that a rapid scale up of HPV vaccination to more than 80% of adolescent girls and continued or increased screening could result in 13 million cases of ICC averted in LMICs and an incidence of ICC less than 4 per 100,000 women worldwide. Robust literature and extensive modeling show us that HPV vaccination is effective in preventing infection with the virus, cervical precancers, ICC, and with the help of biomedical and policy innovation; the near elimination of cervical cancer is possible in countries with robust uptake of the vaccine.

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.