Cervical Intraepithelial Neoplasia Rates in British Columbia Women: A Population-Level Data Linkage Evaluation of the School-Based HPV Immunization Program

Assessing sociodemographic disparities in HPV vaccine uptake among grade 6 and 9 students in the Vancouver Coastal Health region

PURPOSE

To identify sociodemographic factors associated with HPV vaccine uptake in a universal, in-school HPV vaccination program, among grade 6 and 9 students in the regional health authority of Vancouver Coastal Health (VCH), British Columbia (BC), Canada during the 2021/22 school year. VCH operates within the southwest corner of the province of BC serving a mix of urban and rural regions. HPV vaccine is offered in school to all grade 6 students using a two-dose series, with catch up immunizations offered to students in grade 9.

METHODS

We conducted a cross-sectional study of grade 6 and 9 students enrolled in VCH schools for the 2021/22 school year, who also resided within the VCH region. We modelled the associations between sociodemographic explanatory variables (individual-level and group-level) and fully vaccinated outcome using a cross-classified (non-nested) multilevel model.

RESULTS

Among the 17,939 students eligible, 74 % were fully vaccinated for HPV. Immunization coverage was associated with grade, geographic area of residence, school category, social and material deprivation. We demonstrated that grade modified the association between material deprivation and being fully vaccinated. Grade 9 students, including those residing in more materially deprived neighbourhoods, had substantially higher odds (OR 2.01 [95 % CI 1.08, 3.75]) of being fully vaccinated relative to grade 6 students in the least materially deprived neighbourhoods.

CONCLUSIONS

Though publicly funded HPV vaccine is offered to all students in grade 6 and 9, in a space that maximizes programmatic access, sociodemographic factors associated with under-immunized populations were identified. This information can be leveraged for strategic targeting of resources to underimmunized schools or students to mitigate impacts. The repeat offering of HPV vaccine in an older grade (grade 9 in BC) is a key programmatic strategy to reach under-immunized populations and should be complemented by other creative approaches.

Effect of the HPV vaccination programme on incidence of cervical cancer and grade 3 cervical intraepithelial neoplasia by socioeconomic deprivation in England: population based observational study

OBJECTIVES

To replicate previous analyses on the effectiveness of the English human papillomavirus (HPV) vaccination programme on incidence of cervical cancer and grade 3 cervical intraepithelial neoplasia (CIN3) using 12 additional months of follow-up, and to investigate effectiveness across levels of socioeconomic deprivation.

DESIGN

Observational study.

SETTING

England, UK.

PARTICIPANTS

Women aged 20-64 years resident in England between January 2006 and June 2020 including 29 968 with a diagnosis of cervical cancer and 335 228 with a diagnosis of CIN3. In England, HPV vaccination was introduced nationally in 2008 and was offered routinely to girls aged 12-13 years, with catch-up campaigns during 2008-10 targeting older teenagers aged <19 years.

MAIN OUTCOME MEASURES

Incidence of invasive cervical cancer and CIN3.

RESULTS

In England, 29 968 women aged 20-64 years received a diagnosis of cervical cancer and 335 228 a diagnosis of CIN3 between 1 January 2006 and 30 June 2020. In the birth cohort of women offered vaccination routinely at age 12-13 years, adjusted age standardised incidence rates of cervical cancer and CIN3 in the additional 12 months of follow-up (1 July 2019 to 30 June 2020) were, respectively, 83.9% (95% confidence interval (CI) 63.8% to 92.8%) and 94.3% (92.6% to 95.7%) lower than in the reference cohort of women who were never offered HPV vaccination. By mid-2020, HPV vaccination had prevented an estimated 687 (95% CI 556 to 819) cervical cancers and 23 192 (22 163 to 24 220) CIN3s. The highest rates remained among women living in the most deprived areas, but the HPV vaccination programme had a large effect in all five levels of deprivation. In women offered catch-up vaccination, CIN3 rates decreased more in those from the least deprived areas than from the most deprived areas (reductions of 40.6% v 29.6% and 72.8% v 67.7% for women offered vaccination at age 16-18 and 14-16, respectively). The strong downward gradient in cervical cancer incidence from high to low deprivation in the reference unvaccinated group was no longer present among those offered the vaccine.

CONCLUSIONS

The high effectiveness of the national HPV vaccination programme previously seen in England continued during the additional 12 months of follow-up. HPV vaccination was associated with a substantially reduced incidence of cervical cancer and CIN3 across all five deprivation groups, especially in women offered routine vaccination.

Age-Specific Trends of Invasive Cervical Cancer Incidence in British Columbia, Canada, 1971-2017

This study examined invasive cervical cancer (ICC) incidence trends in British Columbia (BC) by age and stage-at-diagnosis relative to World Health Organization ICC elimination targets (4 per 100,000 persons). Incident ICC cases (1971-2017) were obtained from the BC Cancer Registry. Annual age-standardized incidence rates (ASIRs) per 100,000 persons were generated using the direct method. ASIRs were examined among all ages 15+ years and eight age groups using Joinpoint Regression with the Canadian 2011 standard population. Standardized rate ratios (SRRs) compared stage II-IV (late) versus stage I (early) ASIRs by age (2010-2017). ICC ASIRs did not reach the elimination target. ASIRs declined from 18.88 to 7.08 per 100,000 persons (1971-2017). Stronger declines were observed among ages 45+ years, with the largest decline among ages 70-79 years (AAPC = -3.2%, 95% CI = -3.9% to -2.6%). Among ages 25-69 years, varying levels of attenuation in declining trends and stabilization were observed since the 1980s. SRRs indicated higher rates of late-stage ICC among ages 55+ years (SRR-55-69 years = 1.34, 95% CI = 1.08-1.71). Overall, ICC incidence declined in BC since 1971 but did not reach the elimination target. The pace of decline varied across age groups and increased with age. Continued efforts are needed to progress cervical cancer elimination among all age groups.

Human papillomavirus vaccine effectiveness by age at vaccination: A systematic review

Human papillomavirus (HPV) vaccines work by preventing infections prior to natural exposure. Thus, it is likely more effective at younger ages, and it is important to understand how effectiveness might be diminished when administered at older ages. We conducted a systematic review of HPV vaccine effectiveness studies published between 2007 and 2022 that included an analysis of effectiveness against vaccine-type HPV infections, anogenital warts, cervical abnormalities and cervical cancer by age at vaccine initiation or completion. Searching multiple databases, 21 studies were included and results were summarized descriptively. Seventeen studies found the highest vaccine effectiveness in the youngest age group. Vaccine effectiveness estimates for younger adolescents ages 9-14 years ranged from approximately 74% to 93% and from 12% to 90% for adolescents ages 15-18 years. These results demonstrate that the HPV vaccine is most effective against HPV-related disease outcomes when given at younger ages, emphasizing the importance of on-time vaccination.

Human papillomavirus vaccination and cervical cancer risk

Persistent human papillomavirus infection is the central cause of cervical cancer, the leading cause of cancer death among women worldwide. Clear evidence from both randomized trials and population based studies shows that vaccination against human papillomavirus reduces the incidence of cervical pre-cancer. These data suggest that the vaccine reduces the incidence of cervical cancer. However, human papillomavirus vaccine coverage is inadequate in all countries, especially in low and middle income countries where disease burden is highest. Supply side strategies to improve coverage include increasing the availability of low cost vaccines, school located delivery, single dose vaccine schedules, and development of vaccines that do not need refrigeration. Demand side strategies include enhancing provider recommendations, correcting misinformation, and public awareness campaigns. The near elimination of cervical cancer is achievable through increased uptake of human papillomavirus vaccination and efforts to increase screening for cervical cancer, especially when enacted to reduce disparities in across the world.

Real-world impact and effectiveness of the quadrivalent HPV vaccine: an updated systematic literature review

INTRODUCTION

Human papillomavirus (HPV) infection, which poses significant disease burden, is decreasing following implementation of vaccination programs. Synthesized evidence on HPV vaccine real-world benefit was published in 2016. However, long-term impact of vaccination, and how vaccination programs influence infection rates and disease outcomes, requires further examination.

AREAS COVERED

We systematically reviewed observational studies on HPV vaccination within MEDLINE, EMBASE, and Google Scholar from 2016 to 2020, involving 14 years of follow-up data. We identified 138 peer-reviewed publications reporting HPV vaccine impact or effectiveness. Outcomes of interest included rates of infection at different anatomical sites and incidence of several HPV-related disease endpoints.

EXPERT OPINION

The expansion of HPV vaccination programs worldwide has led to a reduction in genital infection and significant decreases in incidence of HPV-related disease outcomes. Therefore, the WHO has set goals for the elimination of cervical cancer as a public health concern. To track progress toward this requires an understanding of the effectiveness of different vaccination initiatives. However, the impact on males, and potential benefit of gender-neutral vaccination programs have not been fully explored. To present an accurate commentary on the current outlook of vaccination and to help shape policy therefore requires a systematic review of available data.

The Use of Medical Claims Data for Identifying Missed Opportunities for HPV Immunization Among Privately Insured Adolescents in the State of Iowa

BACKGROUND

Rates of adolescent human papillomavirus (HPV) vaccination remain low, despite decades of safety and effectiveness data. We sought to quantify the extent of missed opportunities (MOs) for HPV vaccination among adolescents ages 11 to 13 in Iowa and compare the number of these MOs by gender and rurality.

METHODS

Medical claims data from a midwestern insurance provider were used to calculate total numbers of MOs for HPV vaccination for adolescents with continuous health insurance enrollment between ages 11 and 13 (n = 14,505). We divided MOs into several categories: total, among non-initiators, occurring before initiation, occurring after the first dose, and occurring between first and last dose. Finally, we used t-tests to perform subgroup comparisons (urban vs. rural; male vs. female).

RESULTS

Over half of adolescents failed to initiate vaccination by age 13. The majority of MOs occurred prior to initiation. Urban adolescents had more MOs than rural counterparts and males tended to have more MOs than females. Females experienced significantly fewer overall MOs than males 5.98 (SD = 5.49) compared to 6.18 (SD = 6.04) for males. Additionally, among non-initiators, urban females had significantly more MOs overall (M = 7.13; SD = 6.41) compared to rural females (M = 6.58; SD = 5.51).

CONCLUSIONS

Results highlight the extent of MOs that occur at the critical time period between ages 11 and 13. A lack of opportunity was not the barrier to HPV vaccination, particularly among both males and urban adolescents. It will be critical for providers to use known strategies to reduce MOs and utilize all adolescent visits to ensure vaccination is completed by age 13.

Challenges to Adolescent HPV Vaccination and Implementation of Evidence-Based Interventions to Promote Vaccine Uptake During the COVID-19 Pandemic: "HPV Is Probably Not at the Top of Our List"

Introduction

The COVID-19 pandemic has prevented many adolescents from receiving their vaccines, including the human papillomavirus (HPV) vaccine, on time. However, little is known about the impact of the pandemic on implementation of clinic-level evidence-based interventions (EBIs) that help to improve HPV vaccine uptake. In this qualitative study, we explored the pandemic’s impact on EBI implementation and HPV vaccine delivery.

Methods

During August–November 2020, we interviewed clinic managers in a rural, midwestern state about their experiences implementing EBIs for HPV vaccination during the COVID-19 pandemic. We used a multipronged sampling approach with both stratified and purposive sampling to recruit participants from Vaccines for Children clinics. We then conducted a thematic analysis of transcripts.

Results

In interviews (N = 18), 2 primary themes emerged: decreased opportunities for HPV vaccination and disruption to HPV-related implementation work. Most participants reported decreases in opportunities to vaccinate caused by structural changes in how they delivered care (eg, switched to telehealth visits) and patient fear of exposure to COVID-19. Disruptions to EBI implementation were primarily due to logistical challenges (eg, decreases in staffing) and shifting priorities.

Conclusion

During the pandemic, clinics struggled to provide routine care, and as a result, many adolescents missed HPV vaccinations. To ensure these adolescents do not fall behind on this vaccine series, providers and researchers will need to recommit to EBI implementation and use existing strategies to promote vaccination. In the long term, improvements are needed to make EBI implementation more resilient to ensure that progress does not come to a halt in future pandemic events.

Modeling the health and economic implications of adopting a 1-dose 9-valent human papillomavirus vaccination regimen in a high-income country setting: An analysis in the United Kingdom

Although no human papillomavirus (HPV) vaccine is indicated for single-dose administration, some observational evidence suggests that a 1-dose regimen might reduce HPV infection risk to that achieved with 2 doses. This study estimated the potential health and economic outcomes associated with switching from a 2-dose HPV vaccination program for girls and boys aged 13-14 years to an off-label 9-valent (9vHPV), 1-dose regimen, accounting for the uncertainty of the effectiveness and durability of a single dose. A dynamic HPV transmission infection and disease model was adapted to the United Kingdom and included a probabilistic sensitivity analysis using estimated distributions for duration of protection of 1-dose and degree of protection of 1 relative to 2 doses. One-way sensitivity analyses of key inputs were performed. Outcomes included additional cancer and disease cases and the difference in net monetary benefit (NMB). The 1-dose program was predicted to result in 81,738 additional HPV-related cancer cases in males and females over 100 years compared to the 2-dose program, ranging from 36,673 to 134,347 additional cases (2.5% and 97.5% quantiles, respectively), and had a 7.8% probability of being cost-effective at the £20,000/quality-adjusted life years willingness-to-pay (WTP) threshold. In one-way sensitivity analyses, the number of additional cancer cases was sensitive to the median of the duration of protection distribution and coverage rates. The differences in NMBs were sensitive to the median of the duration of protection distribution, dose price and discount rate, but not coverage variations. Across sensitivity analyses, the probability of 1 dose being cost-effective vs 2 doses was < 50% at the standard WTP threshold. Adoption of a 1-dose 9vHPV vaccination program resulted in more vaccine-preventable HPV-related cancer and disease cases in males and females, introduced substantial uncertainty in health and economic outcomes, and had a low probability of being cost-effective compared to the 2-dose program.

The Path to Eliminating Cervical Cancer in Canada: Past, Present and Future Directions

Cervical cancer remains a common cancer affecting women in Canada. While cervical cancer incidence and mortality in Canada have declined for several decades due to the success of organized, provincial cervical cancer screening programs, further decreases will require enhancement of primary, secondary, and tertiary prevention efforts. The present commentary provides a historical overview of cervical cancer trends in Canada, presents current statistics on cervical cancer incidence, mortality and survival, and discusses future directions in relation to cervical cancer elimination.

Real-world impact and effectiveness assessment of the quadrivalent HPV vaccine: a systematic review of study designs and data sources

INTRODUCTION

Vaccine effectiveness and impact studies are typically observational, generating evidence after vaccine launch in a real-world setting. For human papillomavirus (HPV) vaccination studies, the variety of data sources and methods used is pronounced. Careful selection of study design, data capture and analytical methods can mitigate potential bias in such studies.

AREAS COVERED

We systematically reviewed the different study designs, methods, and data sources in published evidence (1/2007-3/2020), which assessed the quadrivalent HPV vaccine effectiveness and impact on cervical/cervicovaginal, anal, and oral HPV infections, anogenital warts, lesions in anus, cervix, oropharynx, penis, vagina or vulva, and recurrent respiratory papillomatosis.

EXPERT OPINION

The rapid growth in access to real-world data allows global monitoring of effects of different public health interventions, including HPV vaccination programs. But the use of data which are not collected or organized to support research also underscore a need to develop robust methodology that provides insight of vaccine effects and consequences of different health policy decisions. To achieve the WHO elimination goal, we foresee a growing need to evaluate HPV vaccination programs globally. A critical appraisal summary of methodology used will provide timely guidance to researchers who want to initiate research activities in various settings.

High-risk HPV prevalence among women undergoing cervical cancer screening: Findings a decade after HPV vaccine implementation in British Columbia, Canada

BACKGROUND

British Columbia (BC) introduced a publicly funded, school-based human papillomavirus (HPV) immunization program in 2008 with the quadrivalent vaccine. In 2010/2011, a baseline evaluation of HPV prevalence was conducted among women undergoing cervical cancer screening. After 10 years of publicly funded HPV vaccination, HPV-type prevalence was re-evaluated.

METHODS

From August 2017 to March 2018, 1107 physicians were invited to return cytobrushes used during routine Pap screening to the Cervical Cancer Screening Laboratory for HPV testing. Only age or year of birth was collected. Specimens were screened for high-risk HPV (hrHPV) and positive samples were genotyped. HPV type prevalence was compared for females 15-22 yrs (those eligible for the school-based vaccination) and 23+ yrs (ineligible for school-based vaccination) for the 2010/2011 and the 2017/2018 data.

RESULTS

There were 3309 valid samples received for testing; of these, 3107 were included in the analysis. The overall hrHPV prevalence was 12.2% (95% CI 11.3-13.3) in 2010/11, and 12.0% (95% CI 10.9-13.2) in 2017/18. For the 15-22 age group, the prevalence for any hrHPV was 26.8% (95% CI 23.1-30.8) in 2010/11 and 25.4% (95% CI 15.3-37.9) in 2017/18. For those aged 15-22, HPV16 prevalence in 2010/11 was 8.8% (95% CI 6.5-11.5) and in 2017/18 was 6.3% (95% CI 1.8-15.5), with corresponding figures for HPV18 3.7% (95% CI 2.3-5.7) and 0% (95% CI 0.0-5.7), respectively. For all hrHPV types, there were no statistically significant differences between the 2010/11 and 2017/18 periods.

CONCLUSIONS

This study illustrates the prevalence of hrHPV in BC over time in women undergoing cervical cancer screening, where an indication of a decline in HPV16/18 is seen in vaccine eligible women.

The ASCCP Cervical Cancer Screening Task Force Endorsement and Opinion on the American Cancer Society Updated Cervical Cancer Screening Guidelines

ABSTRACT

The American Cancer Society (ACS) released updated cervical cancer screening guidelines in 2020 that endorse a shift in practice to primary human papillomavirus (HPV) screening in people with a cervix, beginning at ages of 25-65 years. When access to US Food and Drug Administration-approved primary HPV testing is not available, the ACS offers cotesting or cytology as acceptable alternative strategies but suggests that these testing modalities may be excluded from future iterations of the guidelines. The ASCCP recognizes the benefits and risks of primary HPV cervical cancer screening while acknowledging the barriers to widespread adoption, including implementation issues, the impact of limited HPV vaccination in the United States, and inclusion of populations who may not be well represented on primary HPV screening trials, such as underrepresented minorities. The ASCCP endorses the 2018 US Preventive Services Task Force Recommendation Statement and supports the ACS cervical cancer screening guidelines. Most importantly, the ASCCP endorses any cervical cancer screening for secondary prevention of cervical cancer and recommends interventions that improve screening for those who are underscreened or unscreened.

Current and future vaccine clinical research with the licensed 2-, 4-, and 9-valent VLP HPV vaccines: What's ongoing, what's needed?

Prophylactic HPV vaccination has been a great public health success. For >20 years, clinical trials were conducted with the 2-, 4-, and/or 9-valent vaccines in young-adult females, mid-adult women, males, and adolescents. In all studies, the vaccines were highly efficacious, immunogenic, and well tolerated. Following vaccine licensure and utilization in national vaccine programs globally (real-world settings primarily in high income countries), numerous studies demonstrated that the vaccines continue to have an excellent safety profile and have dramatically reduced the incidence of genital warts, HPV vaccine-type prevalence, and precancerous lesions. Thirty-eight clinical trials with the currently licensed HPV vaccines are ongoing. Key questions being addressed in new trials include: efficacy against persistent infection and immunogenicity of a 1-dose regimen; efficacy of 3 doses in 20-45-year-old females; use in postpartum women and immunocompromised individuals (HIV, liver and kidney transplants); dose sparing via intradermal administration; use in combination with a PD1 monoclonal antibody in patients with cervical cancer; impact on recurrent disease in women undergoing cervical conization; persistence of protection; and use to prevent oropharyngeal cancer. Additional clinical research that should be conducted includes: long-term follow-up, particularly of 1- and 2-dose regimens; further evaluation of flexible 2-dose regimens; immunogenicity of 1- or 2-dose regimens in persons ≥15 years old and immunocompromised populations; safety and immunogenicity of 1 or 2 doses in children <9 years old; assessment of the vaccine in the prevention of transmission; interchangeability with newer HPV vaccines; additional concomitant use studies; and prevention of penile cancer and recurrent respiratory papillomatosis.

Declining rates of cervical intraepithelial neoplasia in British Columbia, Canada: An ecological analysis on the effects of the school-based human papillomavirus vaccination program

Since 2008, girls in British Columbia (BC), Canada, have been offered HPV vaccination through a school-based, publicly funded immunization program. The oldest birth cohort eligible for the vaccination program was born in 1994 and uptake is on average 63%. To evaluate the impact of the HPV vaccine in BC, ecological trends in cervical intraepithelial neoplasia (CIN) rates were assessed in young women before and after the implementation of the HPV vaccination program. Information on all Pap smears and histopathological abnormalities, in calendar years 2004-2017 in women 16-28 years of age in BC were obtained from the population-based BC Cancer Cervix Screening Program database. Rates of CIN 2 and 3 were calculated as the number of cases divided by the number of cytology specimens for that period. Rate ratios (RR) were calculated by negative binomial piecewise regression. Age-centered incidence rates of CIN 2 and 3 in BC declined significantly among women 16-23 years of age after HPV vaccine introduction compared to before vaccine introduction. The overall reduction postvaccination for CIN2 and 3 in women 16-23 years was respectively 62% (95% CI 54-68%) and 65% (95% CI 58-71%). Age-specific rates for CIN2 significantly declined for those 18-22 years of age and for those 19, 20 and 23 years of age for CIN3. Among women 24-28 years of age no decline in CIN2 and 3 rate over time was observed. The observed reduction in CIN 2 and 3 rates since the introduction of the school-based HPV vaccine program might illustrate the population impact of the BC provincial school-based HPV vaccination program.

Cervical cancer screening for individuals at average risk: 2020 guideline update from the American Cancer Society

The American Cancer Society (ACS) recommends that individuals with a cervix initiate cervical cancer screening at age 25 years and undergo primary human papillomavirus (HPV) testing every 5 years through age 65 years (preferred); if primary HPV testing is not available, then individuals aged 25 to 65 years should be screened with cotesting (HPV testing in combination with cytology) every 5 years or cytology alone every 3 years (acceptable) (strong recommendation). The ACS recommends that individuals aged >65 years who have no history of cervical intraepithelial neoplasia grade 2 or more severe disease within the past 25 years, and who have documented adequate negative prior screening in the prior 10 years, discontinue all cervical cancer screening (qualified recommendation). These new screening recommendations differ in 4 important respects compared with the 2012 recommendations: 1) The preferred screening strategy is primary HPV testing every 5 years, with cotesting and cytology alone acceptable where access to US Food and Drug Administration-approved primary HPV testing is not yet available; 2) the recommended age to start screening is 25 years rather than 21 years; 3) primary HPV testing, as well as cotesting or cytology alone when primary testing is not available, is recommended starting at age 25 years rather than age 30 years; and 4) the guideline is transitional, ie, options for screening with cotesting or cytology alone are provided but should be phased out once full access to primary HPV testing for cervical cancer screening is available without barriers. Evidence related to other relevant issues was reviewed, and no changes were made to recommendations for screening intervals, age or criteria for screening cessation, screening based on vaccination status, or screening after hysterectomy. Follow-up for individuals who screen positive for HPV and/or cytology should be in accordance with the 2019 American Society for Colposcopy and Cervical Pathology risk-based management consensus guidelines for abnormal cervical cancer screening tests and cancer precursors.

Human papillomavirus vaccination 2020 guideline update: American Cancer Society guideline adaptation

The American Cancer Society (ACS) presents an adaptation of the current Advisory Committee on Immunization Practices recommendations for human papillomavirus (HPV) vaccination. The ACS recommends routine HPV vaccination between ages 9 and 12 years to achieve higher on-time vaccination rates, which will lead to increased numbers of cancers prevented. Health care providers are encouraged to start offering the HPV vaccine series at age 9 or 10 years. Catch-up HPV vaccination is recommended for all persons through age 26 years who are not adequately vaccinated. Providers should inform individuals aged 22 to 26 years who have not been previously vaccinated or who have not completed the series that vaccination at older ages is less effective in lowering cancer risk. Catch-up HPV vaccination is not recommended for adults aged older than 26 years. The ACS does not endorse the 2019 Advisory Committee on Immunization Practices recommendation for shared clinical decision making for some adults aged 27 through 45 years who are not adequately vaccinated because of the low effectiveness and low cancer prevention potential of vaccination in this age group, the burden of decision making on patients and clinicians, and the lack of sufficient guidance on the selection of individuals who might benefit.