Ecological Association of Human Papillomavirus Vaccination with Cervical Dysplasia Prevalence in the United States, 2007-2014

Evolution and future of cervical cancer screening: from cytology to primary HPV testing and the impact of vaccination

INTRODUCTION

Cervical cancer remains a significant global health challenge despite decades of progress in screening and prevention. Global cervical cancer screening practices vary substantially, with many countries still relying on cytology-based methods, despite evidence supporting the superior performance of human papillomavirus (HPV)-based screening.

AREAS COVERED

This review explores the historical evolution as well as current landscape and policies of cervical cancer screening, with a focus on Western countries. We discuss the gradual transition from cytology to HPV DNA testing as the primary screening method, while recognizing the continuing role of cytology as a triage method. We also argue that HPV vaccination will have a transformative impact on screening practices, necessitating the need for adapting screening strategies to a post-vaccination world.

EXPERT OPINION

The role of cytology in cervical cancer screening will become increasingly limited due to its diminished effectiveness post-HPV vaccination, as many abnormal cytology results will likely be false positives. This could lead to unnecessary procedures, underscoring the need for adjustments in screening strategies and HPV testing to align with the fact that cervical precancerous lesions will become exceedingly rare.

Validating the predicted impact of HPV vaccination on HPV prevalence, cervical lesions, and cervical cancer: A systematic review of population level data and modelling studies

BACKGROUND

We compared model predictions with independently published primary data from population-based studies on the impact of HPV vaccination on HPV prevalence, cervical cancer and its precursors.

METHODS

We searched Cochrane Library, EMBASE, MEDLINE, Web of Science for studies concerning high-income countries published between 2005 to June 2, 2023. Relative risk (RR) for HPV-related outcomes comparing the pre-vaccination and post-vaccination periods were collected from observational and modelling studies. The relationship between vaccination coverage and observed relative reductions was determined using meta-regressions, and we compared model prediction to observations.

FINDINGS

We identified a total of 5649 potential articles, of which one systematic review, 14 observational studies and 32 modelling studies met our inclusion criteria. A clear relation was found between the RR of HPV diseases related outcomes in the pre- versus post-vaccination era and the vaccination coverage, with 23 out of 28 data points and 19 out of 20 data points showing significant reductions in HPV prevalence and CIN2+ prevalence respectively. Around 67 % (n/N = 12/18) of model predictions were more optimistic on HPV prevalence reductions compared to the 95 % CI of the meta-regression derived from observational studies. For CIN2+ lesions, 48 % (n/N = 31/64) of model predictions for CIN2+ outcomes fell within the 95 % CI.

INTERPRETATION

Model predictions and observational data agree that HPV vaccination can have a substantial impact on HPV related outcomes on a population level. Despite large heterogeneity in observational data and modelling studies, it is particularly encouraging that model predictions on the impact of HPV vaccination on CIN2+ model lesions align with observational studies.

FUNDING

Ontario Health (formerly known as Cancer Care Ontario).

Post-marketing study design to evaluate the effectiveness of the 9-valent and 4-valent HPV vaccines on serious HPV-related cervical disease in China

The 4-valent (4 v) and 9-valent (9 v) human papillomavirus (HPV) vaccines are approved in China for females aged 9-45 years. However, the real-world impact of 4vHPV or 9vHPV vaccination for the prevention of high-grade cervical disease in Chinese women is lacking. Two post-marketing surveillance studies will be conducted to measure the occurrence of high-grade cervical lesions in Chinese women who had received ≥1 dose of the 4vHPV (aged 20-45 years) or 9vHPV (aged 16-26 years) vaccine in Ningbo, China. Vaccination data will be extracted from the Ningbo Regional Health Information Platform (NRHIP) from the date of the first 4vHPV (January 9, 2018) or the first 9vHPV (January 25, 2019) vaccination to March 31, 2021. The primary 4vHPV and 9vHPV vaccinated cohorts will include women vaccinated per protocol. The 4vHPV/9vHPV vaccinated test-negative (cervical HPV negative; ThinPrep cytology test negative) and corresponding matched unvaccinated HPV test-negative sub-cohorts will also be assessed. Outcomes will be the occurrence of new-onset cervical intraepithelial neoplasia grade 2/3, adenocarcinoma in situ, and invasive cervical cancer. This study aims to demonstrate that such a methodological approach is feasible and can be used to assess the impact of HPV vaccination in other regions across China.

Cervical High-Grade Squamous Intraepithelial Lesion Burden and Standard of Care Treatment Effectiveness and Safety in the United States, 2008-2018: The EACH-WOMAN Project

OBJECTIVE

Management of cervical high-grade squamous intraepithelial lesions (HSILs), the immediate precursor of cervical cancer, consists largely of surgical treatment for women at higher risk for progression to cancer. The authors' objective was to describe the occurrence of cervical HSIL in the United States and various outcomes for women who received surgical treatment.

METHODS

From a US commercial health insurer, a cohort of adult women with cervical HSIL diagnoses receiving surgical treatment within 3 months of diagnosis between January 2008 and September 2018 was identified. This cohort was followed for several outcomes, including cervical HSIL recurrence, human papillomavirus clearance, preterm birth, infection, and bleeding.

RESULTS

The incidence rate of cervical HSIL declined from 2.34 (95% CI = 2.30-2.39) cases per 1,000 person-years in 2008 to 1.39 (95% CI = 1.35-1.43) cases per 1,000 person-years in 2014, remaining near that level through 2018. Among 65,527 women with cervical HSIL, 47,067 (72%) received surgical treatment within 3 months of diagnosis. Among the women receiving surgical treatment, cervical HSIL recurred in 6% of surgically treated women, whereas 45% of surgically treated women underwent subsequent virological testing that indicated human papillomavirus clearance. Preterm birth was observed in 5.9% by 5 years follow-up and bleeding and infection each at 2.2% by 7 days follow-up.

CONCLUSIONS

From 2008 through 2018, the incidence of diagnosed cervical HSIL decreased for several years before stabilizing. Surgical treatment of HSIL may be beneficial in removing the precancerous lesion, but cervical HSIL may recur, and the surgery is associated with complications including preterm birth, infection, and bleeding.

Updated estimate of the annual direct medical cost of screening and treatment for human papillomavirus associated disease in the United States

The annual direct medical cost attributable to human papillomavirus (HPV) in the United States over the period 2004-2007 was estimated at $9.36 billion in 2012 (updated to 2020 dollars). The purpose of this report was to update that estimate to account for the impact of HPV vaccination on HPV-attributable disease, reductions in the frequency of cervical cancer screening, and new data on the cost per case of treating HPV-attributable cancers. Based primarily on data from the literature, we estimated the annual direct medical cost burden as the sum of the costs of cervical cancer screening and follow-up and the cost of treating HPV-attributable cancers, anogenital warts, and recurrent respiratory papillomatosis (RRP). We estimated the total direct medical cost of HPV to be $9.01 billion annually over the period 2014-2018 (2020 U.S. dollars). Of this total cost, 55.0% was for routine cervical cancer screening and follow-up, 43.8% was for treatment of HPV-attributable cancer, and less than 2% was for treating anogenital warts and RRP. Although our updated estimate of the direct medical cost of HPV is slightly lower than the previous estimate, it would have been substantially lower had we not incorporated more recent, higher cancer treatment costs.

Impact of human papillomavirus vaccine on cervical cancer epidemic: Evidence from the surveillance, epidemiology, and end results program

Introduction

Since 2006, the human papillomavirus (HPV) vaccine has been recommended for females aged 9-26 years in the United States. Aiming to evaluate the early effect of the HPV vaccine on cervical cancer, this study assessed the incidence of cervical cancer by age and histology before and after the introduction of HPV vaccination.

Methods

Data on cervical cancer incidence from 1975-2019 were extracted from the Surveillance, Epidemiology, and End Results Program. Joinpoint regression was used to determine temporal trends over time. Future cervical cancer incidence (2015-2039) was projected using Bayesian age-period-cohort analysis. Age-period-cohort (APC) models were created to evaluate age, period, and cohort effects.

Results

For overall cervical cancer and cervical squamous cell carcinoma (SCC), incidence rate showed decreasing trends (-0.7%, and -1.0% annually, respectively), whereas cervical adenocarcinoma (AC) incidence continuously increased (2.6% annually). The incidence trends for AC were stable in the 20-24 and 25-29-year age groups, whereas there was an increasing trend in older age groups. Similarly, the projected trend for AC in females aged 20-30 years exhibited a decline, whereas an increase was predicted in the 31-40-year age group, especially in the 35-44 year age group. The birth cohort and period effects in SCC and AC were extracted from APC models.

Discussion

During the period of 1975-2019, the incidence of cervical AC remained almost unchanged in the age groups receiving HPV vaccines while increased in the age groups not receiving HPV vaccines. The birth cohort effects of SCC and AC of the cervix provided evidence supporting the effectiveness of the HPV vaccine in preventing cervical cancer.

HPV type-specific trends in cervical precancers in the United States, 2008-2016

Declines in cervical intraepithelial neoplasia grades 2-3 and adenocarcinoma in situ (CIN2+) observed among young women suggest impact from human papillomavirus (HPV) vaccination. To further evaluate vaccine impact including cross-protection and type replacement, we described high-risk (HR)-HPV type-specific cervical precancer incidence rates among women aged 20-39 years, 2008-2016. We analyzed cross-sectional population-based data on 18,344 cases of CIN2+ from a 5-site surveillance system. Diagnostic specimens were tested for individual HPV types, including 14 HR-HPV types (HPV16/18/31/33/35/39/45/51/52/56/58/59/66/68). We estimated age-specific annual HR-HPV type-specific CIN2+ incidence per 100,000 screened women for individual types, vaccine HR-HPV types (HPV16/18) and non-vaccine HR-HPV types (non-HPV16/18). We evaluated trends using average annual percent changes (AAPC) and 95% confidence intervals (CI), and estimated total declines by comparing 2015-2016 to 2008-2009 using incidence rate ratios. Among 20-24-year-olds, HPV16/18-CIN2+ declined from 2008 through 2016 (AAPC: -21.3%, 95% CI: -28.1%, -13.8%), whereas no trend was observed for non-HPV16/18-CIN2+ (AAPC: -1.8%, 95% CI: -8.1%, 4.9%). After 2010, CIN2+ among 20-24-year-olds was more often caused by non-vaccine versus vaccine HR-HPV types. No significant declining trends were observed in older age groups. In 2015-2016 compared to 2008-2009, HPV16-CIN2+ declined 78%, HPV18-CIN2+ 72%, and HPV31-CIN2+ 51% among 20-24-year-olds; no increases were observed in type-specific CIN2+ incidence. Among 25-29-year-olds, HPV16-CIN2+ declined 18%; CIN2+ attributed to seven nonvaccine types increased significantly. No significant declines were observed in older groups. Significant declines in HPV16/18-CIN2+ in 20-24-year-olds and HPV16-CIN2+ in 25-29-year-olds corroborate impact of HPV vaccination. A declining trend in HPV31-CIN2+ is consistent with cross-protection from vaccination.

Human Papillomavirus Vaccine Impact on Cervical Precancers in a Low-Vaccination Population

INTRODUCTION

Demonstrating human papillomavirus vaccine impact is critical for informing guidelines to increase vaccination and decrease human papillomavirus‒related outcomes, particularly in states with suboptimal vaccination coverage, such as Tennessee. This study examines the trends in high-grade cervical lesion incidence among Tennessee Medicaid-enrolled women aged 18-39 years and the subset of women who were screened for cervical cancer.

METHODS

Using a validated claims-based model to identify incident cervical intraepithelial neoplasia Grades 2 or 3 or adenocarcinoma in situ events, annual age group‒specific incidence rates from Tennessee Medicaid billing data, 2008-2018, were calculated. Significant trends were determined by Joinpoint. Analyses were conducted in 2020.

RESULTS

From 2008 to 2018, high-grade cervical lesion incidence significantly declined in women aged 18-20 years (average annual percentage change= -31.9, 95% CI= -38.6, -24.6), 21-24 years (average annual percentage change= -12.9, 95% CI= -22.3, -2.4), and 25-29 years (average annual percentage change= -6.4, 95% CI= -8.1, -4.6). Among screened women, rates significantly declined for ages 18-20 years (average annual percentage change= -20.3, 95% CI= -25.3, -15.0), 21-24 years (average annual percentage change= -10.2, 95% CI= -12.6, -7.8), and 25-29 years (average annual percentage change= -2.6, 95% CI= -3.9, -1.2). Trends from 2008 to 2018 were stable for older age groups (30-34 and 35-39 years).

CONCLUSIONS

Results show reductions in high-grade cervical lesion incidence among ages most likely to have benefited from the human papillomavirus vaccine. Declines among young, screened women suggest causes other than reduction in screening. Evidence of vaccine impact in populations with low-vaccination coverage, such as Tennessee, is promising.

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.

Understanding Human Papillomavirus Vaccine Promotions and Hesitancy in Northern California Through Examining Public Facebook Pages and Groups

Human papillomavirus (HPV) vaccination coverage among adolescents is lower in rural regions and remains under the 80% coverage goal by Healthy People 2030. Through both sentiment analysis and topic modeling, this research examines how local health agencies and groups in nine Northern California counties promote HPV vaccines through Facebook and how target populations react to promotion posts in comments that elucidate their sentiments and hesitancy toward HPV vaccination. In January 2021, we identified 2,105 public Facebook pages and 1,065 groups related to health within the counties and collected a total of 212 posts and 505 comments related to the HPV vaccine. The posts were published between 2010 and 2021, with the majority (83%) published after 2017. There were large variations of Facebook activities across counties. We categorized four counties with HPV vaccination initiation rates below 40% as low-coverage counties and five counties with rates above 40% as high-coverage counties. In general, low-coverage counties had fewer Facebook activities in comparison to high coverage. Results showed that, on average, comments about the HPV vaccine exhibited more positive emotion, more negative emotion, and more anger than the posts. Overall, thematic topics that emerged from posts centered around awareness and screening of HPV and cervical cancer, STI testing services, information sources, and calls to action for health services. However, comment topics did not correspond to posts and were mostly related to vaccine hesitancy, discussing vaccine risks, safety concerns, and distrust in vaccine science, citing misinformation. When comparing high- versus low-coverage counties, posts expressed similar sentiments; however, comments within high-coverage counties expressed more anger than in low-coverage counties. Comments from both high- and low-coverage counties expressed concerns with vaccine safety, risks, and injury. It is important to note that commenters exchanged information sources and tried to address misinformation themselves. Our results suggest that the promotion of HPV vaccines from public Facebook pages and groups is limited in frequency and content diversity. This illustrates problems with generalized social media vaccination promotion without community tailoring and addressing specific hesitancy concerns. Public health agencies should listen to the thoughts of targeted audiences reflected through comments and design relevant messages to address these concerns for HPV vaccination promotion.

The Estimated Lifetime Medical Cost of Diseases Attributable to Human Papillomavirus Infections Acquired in 2018

INTRODUCTION

We estimated the lifetime medical costs of diagnosed cases of diseases attributable to human papillomavirus (HPV) infections acquired in 2018.

METHODS

We adapted an existing mathematical model of HPV transmission and associated diseases to estimate the lifetime number of diagnosed cases of disease (genital warts; cervical intraepithelial neoplasia; and cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers) attributable to HPV infections that were acquired in 2018. For each of these outcomes, we multiplied the estimated number of cases by the estimated lifetime medical cost per case obtained from previous studies. We estimated the costs of recurrent respiratory papillomatosis in a separate calculation. Future costs were discounted at 3% annually.

RESULTS

The estimated discounted lifetime medical cost of diseases attributable to HPV infections acquired in 2018 among people aged 15 to 59 years was $774 million (in 2019 US dollars), of which approximately half was accounted for by infections in those aged 15 to 24 years. Human papillomavirus infections in women accounted for approximately 90% of the lifetime number of diagnosed cases of disease and 70% of the lifetime cost attributable to HPV infections acquired in 2018 among those aged 15 to 59 years.

CONCLUSIONS

We estimated the lifetime medical costs of diseases attributable to HPV infections acquired in 2018 to be $774 million. This estimate is lower than previous estimates, likely due to the impact of HPV vaccination. The lifetime cost of disease attributable to incident HPV infections is expected to decrease further over time as HPV vaccination coverage increases.

Surveillance systems for monitoring cervical cancer elimination efforts: Focus on HPV infection, cervical dysplasia, cervical screening and treatment

In order to achieve the global elimination of cervical cancer as a public health problem, close surveillance of progress in public health and clinical activities and outcomes across the three pillars of vaccination, screening and treatment will be required. Surveillance should ideally occur within an integrated system that is planned, funded, and regularly evaluated to ensure it is providing timely, accurate and relevant feedback for action. In this paper, we conceptualise the main public health surveillance objectives as process and outcome measures in each of the three pillars. Process measures include coverage/participation measures for vaccination, screening and treatment alongside the ongoing assessment of the quality and reach of these programs and activities. Outcome measures related to the natural history of human papillomavirus (HPV) infection include HPV infection prevalence, precursor cervical lesions and cervical cancers (including stage at diagnosis, cancer incidence and mortality). These outcome measures can be used for monitoring the effectiveness of the three core activities in the short, medium and long term to assess whether these interventions are effectively reducing their occurrence. We discuss possible methods for the surveillance of these measures in the context of country capacity, drawing from examples in Australia, the USA and in low and middle income countries.

Economic Value of Lost Productivity Attributable to Human Papillomavirus Cancer Mortality in the United States

Objectives: To estimate years of potential life lost (YPLL) and present value of future lost productivity (PVFLP) associated with premature mortality due to HPV-attributable cancers, specifically those targeted by nonavalent HPV (9vHPV) vaccination, in the United States (US) before vaccine use. Methods: YPLL was estimated from the reported number of deaths in 2017 due to HPV-related cancers, the proportion attributable to 9vHPV-targeted types, and age- and sex-specific US life expectancy. PVFLP was estimated as the product of YPLL by age- and sex-specific probability of labor force participation, annual wage, value of non-market labor, and fringe benefits markup factor. Results: An estimated 7,085 HPV-attributable cancer deaths occurred in 2017 accounting for 154,954 YPLL, with 5,450 deaths (77%) and 121,226 YPLL (78%) attributable to 9vHPV-targeted types. The estimated PVFLP was $3.3 billion for cancer deaths attributable to 9vHPV-targeted types (86% from women). The highest productivity burden was associated with cervical cancer in women and anal and oropharyngeal cancers in men. Conclusions: HPV-attributable cancer deaths are associated with a substantial economic burden in the US, much of which could be vaccine preventable.

Improving Cervical Precancer Surveillance: Validity of Claims-Based Prediction Models in ICD-9 and ICD-10 Eras

Background

Human papillomavirus vaccine (HPV) impact on cervical precancer (cervical intraepithelial neoplasia grades 2+ [CIN2+]) is observable sooner than impact on cancer. Biopsy-confirmed CIN2+ is not included in most US cancer registries. Billing codes could provide surrogate metrics; however, the International Classification of Diseases, ninth (ICD-9) to tenth (ICD-10) transition disrupts trends. We built, validated, and compared claims-based models to identify CIN2+ events in both ICD eras.

Methods

A database of Davidson County (Nashville), Tennessee, pathology-confirmed CIN2+ from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT) provided gold standard events. Using Tennessee Medicaid 2008-2017, cervical diagnostic procedures (N = 8549) among Davidson County women aged 18-39 years were randomly split into 60% training and 40% testing sets. Relevant diagnosis, procedure, and screening codes were used to build models from CIN2+ tissue diagnosis codes alone, least absolute shrinkage and selection operator (LASSO), and random forest. Model-classified index events were counted to estimate incident events.

Results

HPV-IMPACT identified 983 incident CIN2+ events. Models identified 1007 (LASSO), 1245 (CIN2+ tissue diagnosis codes alone), and 957 (random forest) incident events. LASSO performed well in ICD-9 and ICD-10 eras: 77.3% (95% confidence interval [CI] = 72.5% to 81.5%) vs 81.1% (95% CI = 71.5% to 88.6%) sensitivity, 93.0% (95% CI = 91.9% to 94.0%) vs 90.2% (95% CI = 87.2% to 92.7%) specificity, 61.3% (95% CI = 56.6% to 65.8%) vs 60.3% (95% CI = 51.0% to 69.1%) positive predictive value, 96.6% (95% CI = 95.8% to 97.3%) vs 96.3% (95% CI = 94.1% to 97.8%) negative predictive value, 91.0% (95% CI = 89.9% to 92.1%) vs 88.8% (95% CI = 85.9% to 91.2%) accuracy, and 85.1% (95% CI = 82.9% to 87.4%) vs 85.6% (95% CI = 81.4% to 89.9%) C-indices, respectively; performance did not statistically significantly differ between eras (95% confidence intervals all overlapped).

Conclusions

Results confirmed model utility with good performance across both ICD eras for CIN2+ surveillance. Validated claims-based models may be used in future CIN2+ trend analyses to estimate HPV vaccine impact where population-based biopsies are unavailable.

Trends in High-grade Cervical Lesions and Cervical Cancer Screening in 5 States, 2008-2015

BACKGROUND

We describe changes in rates of cervical intraepithelial neoplasia grades 2, 3 and adenocarcinoma in situ (CIN2+) during a period of human papillomavirus (HPV) vaccine uptake and changing cervical cancer screening recommendations.

METHODS

We conducted population-based laboratory surveillance for CIN2+ in catchment areas in 5 states, 2008-2015. We calculated age-specific CIN2+ rates per 100000 women by age groups. We estimated incidence rate ratios (IRR) of CIN2+ for 2-year periods among all women and among screened women to evaluate changes over time.

RESULTS

A total of 16572 CIN2+ cases were reported. Among women aged 18-20 and 21-24 years, CIN2+ rates declined in all sites, whereas in women aged 25-29, 30-34, and 35-39 years, trends differed across sites. The percent of women screened annually declined in all sites and age groups. Compared to 2008-2009, rates among screened women were significantly lower for all 3 periods in women aged 18-20 years (2010-2011: IRR 0.82, 95% confidence interval [CI] 0.67-0.99; 2012-2013: IRR 0.63, 95% CI 0.47-0.85; 2014-2015: IRR 0.44, 95% CI 0.28-0.68) and lower for the latter 2 time periods in women aged 21-24 years (2012-2013: IRR 0.86, 95% CI 0.79-0.94; 2014-2015: IRR 0.61, 95% CI 0.55-0.67).

CONCLUSIONS

From 2008-2015, both CIN2+ rates and cervical cancer screening declined in women aged 18-24 years. The significant decreases in CIN2+ rates among screened women aged 18-24 years are consistent with a population-level impact of HPV vaccination.

Analysis of community-based studies related with knowledge, awareness, attitude, and behaviors towards HPV and HPV vaccine published in Turkey: A systematic review

Human papilloma virus (HPV) vaccine is a proven method for preventing HPV-related cancers and genital warts, especially preventing cervical cancer. It is aimed to systematically review and synthesize conclusions in detail from community-based studies published in Turkey between 2009 and 2019, which evaluate the knowledge, awareness, attitude, and behaviors of individuals towards HPV and HPV vaccination. This systematic review is conducted based on the PRISMA reporting method and includes community-based, descriptive cross-sectional and cross-sectional studies published between 2009 and 2019. In this systematic review, 5132 studies from six databases were scanned in total. It was determined that there were 23 studies that met the eligibility criteria for this systematic review. In the reviewed studies, it was determined that the rate of “Hearing of HPV before” was 3.8% at the lowest and 57.0% at the highest, and the rate of “Hearing of HPV vaccine before” was 2.2% at the lowest and 74.7% at the highest. In the reviewed studies, it was reported that although parents’ willingness to have their daughters vaccinated with HPV vaccine varied between 14.4% and 68.0%, their willingness to have their sons vaccinated with HPV vaccine varied between 11.0% and 62.0%. In addition, it was reported that the lowest rate of vaccination with HPV vaccine among participants was 0.3% at the lowest and 6.0% at the highest. Consequently, it is considered that conducting common, systematic, and continuous health education programs aimed at both sexes and including both parents, which will increase the knowledge and awareness on HPV and its vaccine, would provide positive attitudes, and will be effective in protecting against HPV-related cancers.

HPV: Injecting Truth into the Vaccine and Making Effective Recommendations

Human papillomavirus (HPV) immunization rates are significantly below the Healthy People 2020 target of 80% and lag behind other adolescent vaccines that are given at the same time. There is no top reason for parents' lack of HPV initiation, and many concerns could be addressed by talking to a health care provider. This article aims to equip clinicians with information regarding the impa-cts of HPV, address vaccine concerns, and guide clinicians with best practices regarding effective vaccine recommendations.[Pediatr Ann. 2020;49(6):e244-e247.].

Human Papillomavirus 16/18-Associated Cervical Lesions: Differences by Area-Based Measures of Race and Poverty

INTRODUCTION

This analysis evaluates trends in cervical lesions with human papillomavirus 16/18 detected by area-based measures of race, ethnicity, and poverty during 2008-2015.

METHODS

Trends in the proportion of lesions with human papillomavirus 16/18 detected among residents of New Haven County, Connecticut were examined by area-based measures of race, ethnicity, and poverty. Area-based measures are aggregate descriptors of census tract characteristics useful for measuring differences in health outcomes in the context of where people live. Multivariable logistic regression modeling was conducted, adjusted for individual-level race, ethnicity, and insurance status to assess the independent effects of area-based measures. Data were analyzed in 2018-2019.

RESULTS

Among women aged 21-24 years and 25-29 years, significant declines in the proportion of lesions with human papillomavirus 16/18 were observed. Among women aged 21-24 years, declines began earlier and were greater in magnitude in areas of lower poverty (OR=0.55, 95% CI=0.36, 0.85 for 2010-2012 vs 2008-2009 and OR=0.30, 95% CI=0.18, 0.51 for 2013-2015 vs 2008-2009) compared with higher poverty (OR=1.66, 95% CI=0.86, 3.21 and OR=0.48, 95% CI=0.19, 1.20). Similar patterns were observed for women aged 25-29 years, and for area-based measures of race and ethnicity.

CONCLUSIONS

Differences were observed in declines in the proportion of human papillomavirus 16/18 lesions by area-based measures since the introduction of human papillomavirus vaccines, with greater and earlier declines in areas with fewer residents living in poverty and racial minorities. Ongoing human papillomavirus vaccine impact monitoring is necessary to track differences by sociodemographic characteristics.

Cervical adenocarcinoma in situ: Human papillomavirus types and incidence trends in five states, 2008-2015

Primary prevention through the use of human papillomavirus (HPV) vaccination is expected to impact both cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS). While CIN is well described, less is known about the epidemiology of AIS, a rare cervical precancer. We identified AIS and CIN grade 3 (CIN3) cases through population-based surveillance, and analyzed data on HPV types and incidence trends overall, and among women screened for cervical cancer. From 2008 to 2015, 470 AIS and 6,587 CIN3 cases were identified. The median age of women with AIS was older than those with CIN3 (35 vs. 31 years; p < 0.01). HPV16 was the most frequently detected type in both AIS and CIN3 (57% in AIS; 58% in CIN3), whereas HPV18 was the second most common type in AIS and less common in CIN3 (38% vs. 5%; p < 0.01). AIS lesions were more likely than CIN3 lesions to be positive for high-risk types targeted by the bivalent and quadrivalent vaccines (HPV16/18, 92% vs. 63%; p < 0.01), and 9-valent vaccine (HPV16/18/31/33/45/52/58, 95% vs. 87%; p < 0.01). AIS incidence rates decreased significantly in the 21-24 year age group (annual percent change [APC] overall: -22.1%, 95% CI: -33.9 to -8.2; APC among screened: -16.1%, 95% CI: -28.8 to -1.2), but did not decrease significantly in any older age group. This report on the largest number of genotyped AIS cases to date suggests an important opportunity for vaccine prevention of AIS, and is the first to document a decline in AIS incidence rates among young women during the vaccine era.

Assessing sociodemographic differences in human papillomavirus vaccine impact studies in the United States: a systematic review using narrative synthesis

OBJECTIVES

Sociodemographic disparities in the incidence and mortality of human papillomavirus (HPV)-associated conditions have been well documented in the pre-HPV vaccine era. It is still unknown if the introduction of routine vaccination has been effective in reducing these prevaccine era inequalities. The purpose of this review was to determine the utilization of sociodemographic variables to assess for disparities in population-level HPV vaccine impact research and to evaluate the current evidence for disparities in the reduction of HPV-associated conditions after vaccine introduction in the United States (US).

STUDY DESIGN

A systematic review of the literature from January 2007 through March 2018 was carried out to identify studies evaluating the impact HPV vaccines have had on the rates of HPV infection, genital warts, and cervical dysplasia (cervical intraepithelial neoplasia grades 1+) in the US. An in-depth review was then performed to synthesize these data and to assess the way prior studies have reported and evaluated for potential disparities in the vaccine's impact within various racial, ethnic, and/or socio-economic subgroups of the population.

METHODS

Vaccine impact studies measure the change in the population-level burden of disease prelicensure versus postlicensure of the vaccine. We systematically searched PubMed/Medline and Embase, combining search terms related to the HPV vaccine, sentinel surveillance, and HPV-associated conditions. Eligible studies were those with population-level, postvaccine introduction data that were conducted in the US. Finally, a cited reference search was conducted for all included articles using the Web of Science platform that accesses three major citation indexes: Science Citation Index, Social Sciences Citation Index, and Arts and Humanities Citation Index. This allowed us to screen not only the articles that were cited by our final collection of studies but also the articles that used our selected studies as one of their references. The study protocol is registered in PROSPERO (#CRD42018107579).

RESULTS

Overall, 23 of the 4139 references retrieved assessed the population-level impact of HPV vaccines between January 1, 2007, and March 29, 2018. Among these, 13 (57%) reported sociodemographic data. Only two articles reported stratified results by sociodemographic factors, thereby allowing assessment for potential disparate impact. One of these studies described differences in the impact of the vaccine by race, ethnicity, and income.

CONCLUSION

Although approximately half of the studies that assessed the impact of the HPV vaccine measured sociodemographic characteristics, few presented results in a way that allowed for the identification of potential differences in impact between the relevant subgroups of the population. Determining to what extent, if any, vaccines are reducing known sociodemographic disparities is an important public health priority and an essential step in developing immunization strategies that are beneficial for all.

Longitudinal assessment of abnormal Papanicolaou test rates among women with HIV

OBJECTIVE

To describe longitudinal changes in the prevalence of abnormal Papanicolau testing among women living with HIV.

DESIGN

Prospective cohort study with sequential enrollment subcohorts.

METHODS

Four waves of enrollment occurred in the Women's Interagency HIV Study, the US women's HIV cohort (1994-1995, 2001-2002, 2011-2012, 2013-2015). Pap testing was done at intake, with colposcopy prescribed for any abnormality. Rates of abnormal Pap test results (atypical squamous cells of uncertain significance or worse) and cervical intraepithelial neoplasia grade 2 (CIN2) or worse were calculated. Logistic regression models assessed changes in prevalence across cohorts after controlling for severity of HIV disease and other risk factors for abnormal Pap tests.

RESULTS

The unadjusted prevalence of any Pap abnormality was 679/1769 (38%) in the original cohort, 195/684 (29%) in the 2001-2002 cohort, 46/231 (20%) in the 2011-2012 cohort, and 71/449 (16%) in the 2013-2015 cohort. In multivariable analysis, compared with risk in the 1994-1995 cohort, the adjusted risk in the 2001-2002 cohort was 0.79 (95% CI 0.59-1.05), in the 2011-2012 cohort was 0.67 (95% CI 0.43-1.04), and in the 2013-2015 cohort was 0.41 (95% CI 0.27-0.62) with P for trend less than 0.0001.

CONCLUSION

Rates of abnormal cytology among women with HIV have fallen during the past two decades.

Facts or stories? How to use social media for cervical cancer prevention: A multi-method study of the effects of sender type and content type on increased message sharing

Social media has become a valuable tool for disseminating cancer prevention information. However, the design of messages for achieving wide dissemination remains poorly understood. We conducted a multi-method study to identify the effects of sender type (individuals or organizations) and content type (personal experiences or factual information) on promoting the spread of cervical cancer prevention messages over social media. First, we used observational Twitter data to examine correlations between sender type and content type with retweet activity. Then, to confirm the causal impact of message properties, we constructed 900 experimental tweets according to a 2 (sender type) by 2 (content type) factorial design and tested their probabilities of being shared in an online platform. A total of 782 female participants were randomly assigned to 87 independent 9-person online groups and each received a unique message feed of 100 tweets drawn from the 4 experimental cells over 5 days. We conducted both tweet-level and group-level analyses to examine the causal effects of tweet properties on influencing sharing behaviors. Personal experience tweets and organizational senders were associated with more retweets. However, the experimental study revealed that informational tweets were shared significantly more (19%, 95% CI: 11 to 27) than personal experience tweets; and organizational senders were shared significantly more (10%, 95% CI: 3 to 18) than individual senders. While rare personal experience messages can achieve large success, they are generally unsuccessful; however, there is a reproducible causal effect of messages that use organizational senders and factual information for achieving greater peer-to-peer dissemination.

Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

BACKGROUND

More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+) to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.

METHODS

In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.

FINDINGS

We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+. After 5-8 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0·17, 95% CI 0·11-0·25) among girls aged 13-19 years, and decreased significantly by 66% (RR 0·34, 95% CI 0·23-0·49) among women aged 20-24 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0·46, 95% CI 0·33-0·66) among girls aged 13-19 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0·33, 95% CI 0·24-0·46) among girls aged 15-19 years, decreased significantly by 54% (RR 0·46, 95% CI 0.36-0.60) among women aged 20-24 years, and decreased significantly by 31% (RR 0·69, 95% CI 0·53-0·89) among women aged 25-29 years. Among boys aged 15-19 years anogenital wart diagnoses decreased significantly by 48% (RR 0·52, 95% CI 0·37-0·75) and among men aged 20-24 years they decreased significantly by 32% (RR 0·68, 95% CI 0·47-0·98). After 5-9 years of vaccination, CIN2+ decreased significantly by 51% (RR 0·49, 95% CI 0·42-0·58) among screened girls aged 15-19 years and decreased significantly by 31% (RR 0·69, 95% CI 0·57-0·84) among women aged 20-24 years.

INTERPRETATION

This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects.

FUNDING

WHO, Canadian Institutes of Health Research, Fonds de recherche du Québec - Santé.

Declines in HPV vaccine type prevalence in women screened for cervical cancer in the United States: Evidence of direct and herd effects of vaccination

BACKGROUND

Human papillomavirus (HPV) vaccine has been recommended in the United States since 2006 for routine vaccination of girls at age 11-12 years and through age 26 years for women not previously vaccinated. Changes in vaccine-type HPV (VT) prevalence can be used to evaluate vaccine impact, including herd effects.

METHODS

We determined type-specific HPV in cytology specimens from women aged 20-29 years screened for cervical cancer at Kaiser Permanente Northwest in 2007 and in two vaccine era periods: 2012-2013 and 2015-2016. Detection and typing used L1 consensus PCR with hybridization for 37 types, including quadrivalent vaccine types (HPV 6/11/16/18).

RESULTS

Among 20-24 year-olds in 2012-2013 and 2015-2016, 44% and 64% had a history of ≥1-dose vaccination. VT prevalence decreased from 13.1% in 2007 to 2.9% in 2015-2016 (prevalence ratio [PR] = 0.22; 95% confidence interval [CI] 0.17-0.29). HPV 31 prevalence was also lower in the vaccine periods compared with 2007. VT prevalence in 2015-2016 among 20-24 year-olds was lower in both vaccinated, 1.3% (PR = 0.10; 95% CI 0.06-0.16), and unvaccinated women, 5.8% (PR = 0.45; 95% CI 0.33-0.61). Among 25-29 year-olds, 21% and 32% had a history of ≥1-dose vaccination. VT prevalence decreased from 8.1% in 2007 to 5.0% in 2015-2016 (PR = 0.62; 95% CI 0.50-0.78). Non-VT high risk prevalence was higher in the vaccine periods compared with the pre-vaccine era in both age groups, however, not in 2015-2016 compared with 2012-2013.

CONCLUSION

Within 9-10 years of vaccine introduction, VT prevalence decreased 78% among 20-24 year-olds and 38% in 25-29 year-olds. There were declines in both vaccinated and unvaccinated women, showing evidence of direct and herd protection.

HPV Vaccine: Updates and Highlights

HPV is the most common sexually transmitted biological agent and is the cause of many conditions in men and women, including precancer lesions and cancer. Three prophylactic HPV vaccines targeting high-risk HPV types are available in many countries worldwide: 2-, 4- and 9-valent vaccines. All the 3 vaccines use recombinant DNA technology and are prepared from the purified L1 protein that self-assembles to form HPV type-specific empty shells. This non-systematic review aims to summarize the HPV epidemiology and the vaccine development to review the landmark trials of HPV vaccine, to present to most remarkable results from clinical trials and the real world, and to stress the challenges and the barriers for HPV vaccine implementation.

Trends in Human Papillomavirus Vaccine Types 16 and 18 in Cervical Precancers, 2008-2014

BACKGROUND

The impact of human papillomavirus (HPV) vaccination has been observed in the United States through declining cervical precancer incidence in young women. To further evaluate vaccine impact, we described trends in HPV vaccine types 16/18 in cervical precancers, 2008-2014.

METHODS

We analyzed data from a 5-site, population-based surveillance system. Archived specimens from women age 18-39 years diagnosed with cervical intraepithelial neoplasia grades 2-3 or adenocarcinoma in situ (CIN2+) were tested for 37 HPV types. We described the proportion and estimated number of cases of CIN2+ by HPV-type groups over time. Trends in HPV16/18-positive CIN2+ were examined, overall and by vaccination status, age, histologic grade, and race/ethnicity, using Cochrane-Armitage tests.

RESULTS

In 10,206 cases, the proportion and estimated number of cases of HPV16/18-positive CIN2+ declined from 52.7% (1,235 cases) in 2008 to 44.1% (819 cases) in 2014 (P < 0.001). Declining trends in the proportion of HPV16/18-positive CIN2+ were observed among vaccinated (55.2%-33.3%, P < 0.001) and unvaccinated (51.0%-47.3%, P = 0.03) women; ages 18-20 (48.7%-18.8%, P = 0.02), 21-24 (53.8%-44.0%, P < 0.001), 25-29 (56.9%-42.4%, P < 0.001), and 30-34 (49.8%-45.8%, P = 0.04) years; CIN2 (40.8%-29.9%, P < 0.001) and CIN2/3 (61.8%-46.2%, P < 0.001); non-Hispanic white (59.5%-47.9%, P < 0.001) and non-Hispanic black (40.7%-26.5%, P < 0.001).

CONCLUSIONS

From 2008-2014, the proportion of HPV16/18-positive CIN2+ declined, with the greatest declines in vaccinated women; declines in unvaccinated women suggest herd protection.

IMPACT

The declining proportion of HPV16/18-positive CIN2+ provides additional evidence of vaccine impact in the United States.

Cost-effectiveness of nonavalent HPV vaccination among males aged 22 through 26 years in the United States

INTRODUCTION

In the United States, routine human papillomavirus (HPV) vaccination is recommended for females and males at age 11 or 12 years; the series can be started at age 9 years. Vaccination is also recommended for females through age 26 years and males through age 21 years. The objective of this study was to assess the health impact and cost-effectiveness of harmonizing female and male vaccination recommendations by increasing the upper recommended catch-up age of HPV vaccination for males from age 21 to age 26 years.

METHODS

We updated a published model of the health impact and cost-effectiveness of 9-valent human papillomavirus vaccine (9vHPV). We examined the cost-effectiveness of (1) 9vHPV for females aged 12 through 26 years and males aged 12 through 21 years, and (2) an expanded program including males through age 26 years.

RESULTS

Compared to no vaccination, providing 9vHPV for females aged 12 through 26 years and males aged 12 through 21 years cost an estimated $16,600 (in 2016 U.S. dollars) per quality-adjusted life year (QALY) gained. The estimated cost per QALY gained by expanding male vaccination through age 26 years was $228,800 and ranged from $137,900 to $367,300 in multi-way sensitivity analyses.

CONCLUSIONS

The cost-effectiveness ratios we estimated are not so favorable as to make a strong economic case for recommending expanding male vaccination, yet are not so unfavorable as to preclude consideration of expanding male vaccination. The wide range of plausible results we obtained may underestimate the true degree of uncertainty, due to model limitations. For example, the cost per QALY might be less than our lower bound estimate of $137,900 had our model allowed for vaccine protection against re-infection. Models that specifically incorporate men who have sex with men (MSM) are needed to provide a more comprehensive assessment of male HPV vaccination strategies.

Effectiveness of catch-up human papillomavirus vaccination on incident cervical neoplasia in a US health-care setting: a population-based case-control study

BACKGROUND

The population effectiveness of human papillomavirus (HPV) catch-up vaccination, defined in the USA as first vaccination at ages 13-26 years, has not been studied extensively. We aimed to assess the risk of cervical intraepithelial neoplasia (CIN) 2, CIN3, adenocarcinoma in situ, or cancer (CIN2+ and CIN3+) by prior HPV vaccination status, age at first dose, and number of doses in women participating in a screening programme within a large integrated health-care system.

METHODS

We performed a nested case-control study of women enrolled in Kaiser Permanente Northern California (an integrated health-care delivery system in California, USA). Cases were women with CIN2+ or CIN3+ confirmed by histology between Jan 1, 1995, and June 30, 2014, and incidence density-selected controls were age-matched women without CIN2+ or CIN3+ at the time each case occurred. For each case, we randomly selected five controls. Cases and controls were aged 26 years or younger when the HPV quadrivalent vaccine became available in 2006. Rate ratios (RRs) from conditional logistic regression were estimated by age at time of first HPV quadrivalent vaccine dose (14-17 years, 18-20 years, and ≥21 years), and number of doses (one, two, and three or more doses) compared with no prior vaccination, with adjustment for smoking, hormonal contraceptive prescription, race or ethnicity, sexually transmitted infections, immunosuppression, parity, and number of outpatient visits.

FINDINGS

4357 incident CIN2+ cases and 21 773 matched controls were included in the study. Of these, 1849 were incident CIN3+ cases with 9242 matched controls. The youngest age at time of first vaccination was 14 years. One or more HPV vaccine doses conferred protection against CIN2+ (RR 0·82, 95% CI 0·73-0·93) and CIN3+ (0·77, 0·64-0·94). We found the strongest protection against CIN2+ in women who had received at least three vaccine doses and had received their first dose aged 14-17 years (0·52, 0·36-0·74) or aged 18-20 years (0·65, 0·49-0·88). No significant protection was found in women aged 21 years or older at time of first dose (0·94, 0·81-1·09). Inferences were similar for CIN3+, but with stronger effects for women who received at least three vaccine doses and had received their first dose aged 14-17 years (0·27, 0·13-0·56) or aged 18-20 years (0·59, 0·36-0·97).

INTERPRETATION

Catch-up quadrivalent HPV vaccination with three doses was effective against CIN2+ and CIN3+ in girls and women aged 14-20 years at time of first vaccine dose but not for women aged 21 years and older at first dose.

FUNDING

US National Cancer Institute.

Cervical Cancer Incidence in Young U.S. Females After Human Papillomavirus Vaccine Introduction

INTRODUCTION

Since 2006, human papillomavirus vaccine has been recommended for young females in the U.S. This study aimed to compare cervical cancer incidence among young women before and after the human papillomavirus vaccine was introduced.

METHODS

This cross-sectional study used data from the National Program for Cancer Registries and Surveillance, Epidemiology, and End Results Incidence-U.S. Cancer Statistics 2001-2014 database for U.S. females aged 15-34 years. This study compared the 4-year average annual incidence of invasive cervical cancer in the 4 years before human papillomavirus vaccine was introduced (2003-2006) and the 4 most recent years in the vaccine era (2011-2014). Joinpoint regression models of cervical incidence from 2001 to 2014 were fitted to identify the discrete joints (year) that represent statistically significant changes in the direction of the trend after the introduction of human papillomavirus vaccination in 2006. Data were collected in 2001-2014, released, and analyzed in 2017.

RESULTS

The 4-year average annual incidence rates for cervical cancer in 2011-2014 were 29% lower than that in 2003-2006 (6.0 vs 8.4 per 1,000,000 people, rate ratio=0.71, 95% CI=0.64, 0.80) among females aged 15-24 years, and 13.0% lower among females aged 25-34 years. Joinpoint analyses of cervical cancer incidence among females aged 15-24 years revealed a significant joint at 2009 for both squamous cell carcinoma and non-squamous cell carcinoma. Among females aged 25-34 years, there was no significant decrease in cervical cancer incidence after 2006.

CONCLUSIONS

A significant decrease in the incidence of cervical cancer among young females after the introduction of human papillomavirus vaccine may indicate early effects of human papillomavirus vaccination.

Trends in High-Grade Cervical Cancer Precursors in the Human Papillomavirus Vaccine Era

INTRODUCTION

The 2006 introduction of human papillomavirus vaccine targeted against genotypes 6, 11, 16, and 18 should result in decreased cervical dysplasia in vaccinated women. However, new cervical cancer guidelines to increase screening intervals complicate interpretation of trends. The hypothesis is that cervical dysplasia would decrease only in young vaccine-eligible women, and not older women.

METHODS

The authors identified Davidson County, Tennessee, women aged 18-39 years with cervical intraepithelial neoplasia (CIN) grade 2 or greater and adenocarcinoma in situ, denoted as CIN2+, through pathology reports from laboratories serving this population. Biopsy specimens for human papillomavirus genotyping were collected. Trends in CIN2+ rates and associated human papillomavirus genotypes, 2008 through 2013, were examined.

RESULTS

The authors identified 2,031 women with CIN2+. Rates of CIN2+ fell from 188.9 to 58.7 per 100,000 women aged 18-20 years (annual percentage change= -24.2, 95% CI= -41.4, -2.1) and from 495.6 to 332.4 per 100,000 women aged 21-24 years (annual percentage change= -10.2%, 95% CI= -16.3, -3.4). There was no significant change in CIN2+ rates for women aged 25-29 or 30-39 years. In biopsy specimens from 1,319 of 2,031 (65%) women, at least one human papillomavirus genotype was identified in 1,270 (96%). The prevalence of at least one of four vaccine human papillomavirus genotypes (6, 11, 16, and 18) declined from 59% in 2008 to 52% in 2013 (p=0.003).

CONCLUSIONS

Diagnosis of CIN2+ decreased in women aged 18-24 years, but not in older women. Both changes in screening and human papillomavirus vaccination could have contributed to the decline of CIN2+ in young women.

Human papillomavirus vaccination coverage among females and males, National Health and Nutrition Examination Survey, United States, 2007-2016

BACKGROUND

Human papillomavirus (HPV) vaccination has been routinely recommended at age 11-12 years in the United States for females since 2006 and males since 2011. Coverage can be estimated using self/parent-reported HPV vaccination collected in the National Health and Nutrition Examination Survey (NHANES) for a wider age range than other national surveys. We assessed vaccination coverage in 2015-2016, temporal trends by age, and the validity of self/parent-reported vaccination status.

METHODS

Participants aged 9-59 years completed an interview collecting demographic and vaccination information. Weighted coverage was estimated for two-year NHANES cycles by age group for 2007-2008 to 2015-2016 for females (N = 14318) and 2011-2012 to 2015-2016 for males (N = 7847). Temporal trends in coverage were assessed from 2007-2008 to 2011-2012 for females and from 2011-2012 to 2015-2016 for both sexes. Sensitivity and specificity of self/parent-reported vaccination were assessed using provider-verified vaccination records from a pilot study in 14-29 year-olds.

RESULTS

In 2015-2016, ≥1 dose coverage among females was highest in 14-19 (54.7%) and 20-24 (56.0%) year-olds and lower in successively older age groups. Among males, ≥1 dose coverage was highest in 14-19 year-olds (39.5%) and lower at older ages. Coverage was similar in 9-13 year-old females and males. Between 2007-2008 and 2011-2012, there were increases among females younger than 30 years. Between 2011-2012 and 2015-2016, there were increases among female age groups including 20-39 year-olds; male coverage increased among ages 9-13, 14-19, and 20-24 years. Self/parent-reported receipt of ≥1 dose had a sensitivity and specificity of 87.0% and 83.3%. Performance was lower for 3 doses.

CONCLUSIONS

While overall HPV vaccination coverage remains low, it is higher in females than males, except in 9-13 year-olds. There have been increases in coverage among many age groups, but coverage has stalled in younger females. Adequate validity was demonstrated for self/parent-reported vaccination of ≥1 dose, but not 3 doses, in a pilot study.

Ten Years of Human Papillomavirus Vaccination in the United States

Since human papillomavirus (HPV) vaccine was first introduced for females in the United States in 2006, vaccination policy has evolved as additional HPV vaccines were licensed and new data became available. The United States adopted a gender neutral routine HPV immunization policy in 2011, the first country to do so. Vaccination coverage is increasing, although it remains lower than for other vaccines recommended for adolescents. There are various reasons for low coverage, and efforts are ongoing to increase vaccine uptake. The safety profile of HPV vaccine has been well established from 10 years of postlicensure monitoring. Despite low coverage, the early effects of the HPV vaccination program have exceeded expectations.

Declines in Human Papillomavirus (HPV)-Associated High-Grade Cervical Lesions After Introduction of HPV Vaccines in Connecticut, United States, 2008-2015

Background

Trends in human papillomavirus (HPV)-associated cervical lesions can provide an indication of vaccine impact. Our purpose was to measure trends in cervical lesions during 2008-2015 and to consider possible explanations including vaccination coverage, changes in screening for cervical cancer, and risk behaviors for acquiring HPV.

Methods

Connecticut (CT) implemented mandatory reporting of cervical intraepithelial neoplasia grades 2/3 and adenocarcinoma in situ (cervical intraepithelial neoplasia grade 2 or higher [CIN2+]) in 2008. Trends by age and birth cohort were modeled using negative binomial regression and change-point methods. To evaluate possible explanations for changes, these trends were compared to changes in HPV vaccination coverage, cervical cancer screening, an antecedent event to detection of a high-grade lesion, and changes in sexual behaviors and Chlamydia trachomatis, an infection with similar epidemiology to and shared risk factors for HPV.

Results

A significant decline in CIN2+ was first evident among women aged 21 years in 2010, followed by successive declines in women aged 22-26 years during 2011-2012. During 2008-2015, the rates of CIN2+ declined by 30%-74% among women aged 21-26 years, with greater declines observed in the younger women. Birth cohorts between 1985 and 1994 all experienced significant declines during the surveillance period, ranging from 25% to 82%. Ecological comparisons revealed substantial increases in HPV vaccination during this time period, and more modest reductions in cervical cancer screening and sexual risk behaviors.

Conclusions

The age and cohort patterns in our data suggest that declines in CIN2+ during 2008-2015 are more likely driven by HPV vaccination, introduced in 2006, than by changes in screening or risk behavior.

Clinical management and risk reduction in women with low-grade squamous intraepithelial lesion cytology: A population-based cohort study

We analyzed the management and risk of subsequent cervical intraepithelial neoplasm 3 (CIN3) and invasive cervical cancer in women with low-grade squamous intraepithelial lesion (LSIL) cytology. A total of 53,293 women with a new diagnosis of cytologic LSIL were identified in Taiwan’s national cervical screening registration database. Based on the retrieved clinical management data, the incidence of subsequent CIN3+ lesions was determined, and the hazard ratios (HRs) were estimated using a Cox proportional hazards model. The average follow-up was 5.02 years. A total of 988 women developed CIN3+ lesions during this period, with an overall incidence of 369.3 women per 100,000 person-years. Cryotherapy and conization/loop electrosurgical excision procedure (LEEP) decreased the subsequent risk of CIN3+ lesions in women younger than 50 years (HR 0.49, 95% confidence interval [CI] 0.37–0.64, p<0.0001 for cryotherapy; HR 0.39, 95% CI 0.27–0.55, p<0.0001 for LEEP). Cryotherapy and conization/LEEP were two significant protective factors for developing CIN3+ lesions, especially in women with biopsy-proven CIN1 (HR 0.55, 95% CI 0.37–0.82, p = 0.003 for cryotherapy; HR 0.43, 95% CI 0.24–0.77, p = 0.005 for LEEP). These results suggest that when women are first screened LSIL and lack prior abnormal cervical cytology, cryotherapy should be one of the treatment options. Younger women with a histological biopsy diagnosis of CIN1 were most likely to benefit from cryotherapy.

Declines in Anogenital Warts Among Age Groups Most Likely to Be Impacted by Human Papillomavirus Vaccination, United States, 2006-2014

OBJECTIVES

To detect decreases in anogenital warts (AGW) among sex and age groups likely to be affected by human papillomavirus vaccination.

METHODS

We estimated annual AGW prevalence during 2006 to 2014 using health care claims among US private health insurance enrollees aged 15 to 39 years. We derived AGW diagnoses using 1 of the following: (1) condylomata acuminata diagnosis, (2) viral wart diagnosis combined with a benign anogenital neoplasm diagnosis or destruction or excision of an anogenital lesion, or (3) AGW medication combined with a benign anogenital neoplasm diagnosis or destruction or excision of an anogenital lesion.

RESULTS

Prevalence decreased during 2008 to 2014 among females aged 15 to 19 years (annual percentage change [APC] = -14.1%; P < .001) and during 2009 to 2014 among women aged 20 to 24 years (APC = -12.9%; P < .001) and among women aged 25 to 29 years (APC = -6.0%; P = .001). We observed significant declines among men aged 20 to 24 years (APC = -6.5%; P = .005). Prevalence increased or was stable in all other sex and age groups.

CONCLUSIONS

We observed AGW decreases among females in the age groups most likely to be affected by human papillomavirus vaccination and decreases in men aged 20 to 24 years. Decreased prevalence in young men is likely attributable to herd protection from vaccination among females.

Prevalence of Human Papillomavirus Among Females After Vaccine Introduction-National Health and Nutrition Examination Survey, United States, 2003-2014

Background

Human papillomavirus (HPV) vaccine was recommended in 2006 for routine vaccination of US females aged 11-12 years. Most vaccine used through 2014 was quadrivalent vaccine (4vHPV), which prevents HPV-6, -11, -16, and -18 infection. To evaluate vaccine impact, we measured HPV prevalence in the National Health and Nutrition Examination Survey (NHANES).

Methods

We analyzed HPV DNA types detected in self-collected cervicovaginal specimens and demographic, sexual behavior, and self-reported vaccination data from females 14-34 years old. We estimated HPV prevalence in the prevaccine (2003-2006) and vaccine eras (2007-2010 and 2011-2014).

Results

Among 14- to 19-year-olds, 4vHPV-type prevalence decreased from 11.5% (95% confidence interval [CI], 9.1%-14.4%) in 2003-2006 to 3.3% (95% CI, 1.9%-5.8%) in 2011-2014, when ≥1-dose coverage was 55%. Among 20- to 24-year-olds, prevalence decreased from 18.5% (95% CI, 14.9%-22.8%) in 2003-2006 to 7.2% (95% CI, 4.7%-11.1%) in 2011-2014, when ≥1-dose coverage was 43%. Compared to 2003-2006, 4vHPV prevalence in sexually active 14- to 24-year-olds in 2011-2014 decreased 89% among those vaccinated and 34% among those unvaccinated. Vaccine effectiveness was 83%.

Conclusions

Within 8 years of vaccine introduction, 4vHPV-type prevalence decreased 71% among 14- to 19-year-olds and 61% among 20- to 24-year-olds. Estimated vaccine effectiveness was high. The decrease in 4vHPV-type prevalence among unvaccinated females suggests herd protection.

Progress in prophylactic human papillomavirus (HPV) vaccination in 2016: A literature review

Prophylactic human papillomavirus (HPV) vaccine represents a revolutionary step forward in preventing HPV-related cancers, especially cervical carcinoma. Alongside appropriate screening, it has the potential to dramatically reduce cervical cancer incidence and even eradicate it. Following extensive evaluations in clinical trials, the first decade of routine HPV vaccine use provides overwhelming evidence of the vaccines' safety and their real-life effectiveness. In 2016, further clinical trials showed high vaccine efficacy in adult women, especially those that were HPV DNA-negative at baseline, and indicated possible protection from HPV-related diseases after treatment of precancerous cervical lesions. The recommendation for a two-dose schedule in individuals under 15 is further supported for all three licensed vaccines by immunogenicity studies that show non-inferior immune responses and similar clinical efficacy compared to the three-dose schedule. So far, natural competition between HPV types has not been confirmed and therefore vaccine-induced clinically significant type replacement is unlikely. The real-world effectiveness data showed cross-sectional reduction in the prevalence/incidence of vaccine-related HPV types, genital warts and precancerous cervical lesions in countries and regions with HPV vaccination coverage. These declines were evident not only in vaccinated females, but also in unvaccinated females and males, strongly suggesting herd protection. Despite an excellent safety profile consistently demonstrated in clinical trials and confirmed in real-life settings, recently invented controversial syndromes allegedly linked to HPV vaccines temporarily compromised some previously very successful vaccination programs and significantly contributed to the failure of HPV vaccine implementation in some countries with the highest prevalence of cervical cancer. However, several safety studies failed to confirm any association of these syndromes with HPV vaccination in various settings and geographic locations. The main challenges remain implementing HPV vaccination in national vaccination programs, especially in low-and middle-income countries with the highest burden of cervical cancer, and achieving and sustaining high vaccine coverage rates.