Impact of human papillomavirus (HPV) vaccination on HPV 16/18-related prevalence in precancerous cervical lesions

Cancer vaccines: past, present and future; a review article

Immunotherapy and vaccines have revolutionized disease treatment and prevention. Vaccines against infectious diseases have been in use for several decades. In contrast, only few cancer vaccines have been approved for human use. These include preventative vaccines against infectious agents associated with cancers, and therapeutic vaccines used as immunotherapy agents to treat cancers. Challenges in developing cancer vaccines include heterogeneity within and between cancer types, screening and identification of appropriate tumour-specific antigens, and the choice of vaccine delivery platforms. Recent advances in all of these areas and the lessons learnt from COVID-19 vaccines have significantly boosted interest in cancer vaccines. Further advances in these areas are expected to facilitate development of effective novel cancer vaccines. In this review, we aim to discuss the past, the present, and the future of cancer vaccines.

Feasibility and acceptability of nationwide HPV vaccine introduction in Senegal: Findings from community-level cross-sectional surveys, 2020

In Senegal, cervical cancer is the most common cancer among women and the leading cause of morbidity and mortality from all cancers. In 2018, Senegal launched a national human papillomavirus (HPV) vaccination program with Gavi, the Vaccine Alliance (Gavi), support. HPV vaccination was incorporated into the national immunization program as a two-dose schedule, with a 6-12-month interval, to nine-year-old girls via routine immunization (RI) services at health facilities, schools and community outreach services throughout the year. During February to March 2020, we conducted interviews to assess the awareness, feasibility, and acceptability of the HPV vaccination program with a cross-sectional convenience sample of healthcare workers (HCWs), school personnel, community healthcare workers (cHCWs), parents, and community leaders from 77 rural and urban health facility catchment areas. Participants were asked questions on HPV vaccine knowledge, delivery, training, and community acceptability of the program. We conducted a descriptive analysis stratified by respondent type. Data were collected from 465 individuals: 77 HCW, 78 school personnel, 78 cHCWs, 152 parents, and community leaders. The majority of HCWs (83.1%) and cHCWs (74.4%) and school personnel (57.7%) attended a training on HPV vaccine before program launch. Of all respondents, most (52.5-87.2%) were able to correctly identify the target population. The majority of respondents (60.2-77.5%) felt that the vaccine was very accepted or accepted in the community. Senegal's HPV vaccine introduction program, among the first national programs in the African region, was accepted by community stakeholders. Training rates were high, and most respondents identified the target population correctly. However, continued technical support is needed for the integration of HPV vaccination as a RI activity for this non-traditional age group. The Senegal experience can be a useful resource for countries planning to introduce the HPV vaccine.

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.

Effectiveness of HPV vaccine by age at vaccination and number of doses: protocol for a population-based matched case-control study

INTRODUCTION

In 2006, the first human papillomavirus (HPV) vaccine was approved by the Food and Drug Administration in the USA based on pre-licensure clinical trials that found it to be highly efficacious at preventing persistent infection and precancerous, high-grade cervical lesions (HGCLs) caused by viral types the vaccine protects against. However, the real-world effectiveness of HPV vaccines as used in clinical practice may be quite different from the efficacy found in pre-licensure clinical trials. More than 10 years have passed since the introduction of the vaccine programme. It is critical to determine if the full benefits of HPV are being realised in real-world settings.

METHODS AND ANALYSIS

The objectives of this study were to estimate the effectiveness of HPV vaccines as used in real-world clinical settings and to determine the degree to which the vaccine's effectiveness varies based on age at the time of immunisation and the number of doses received. The study will be a population-based, matched case-control study. Cases will be women with newly diagnosed HGCL associated with HPV types 16 and 18. Matched controls will be women with a normal Pap test result, matched individually to cases in a 2:1 ratio by age, a practice and date of testing. Medical records will be reviewed to determine dates of receipt of the HPV vaccine for all participants. We will use multivariate conditional logistic regression to control for potential confounders.

ETHICS AND DISSEMINATION

This protocol presents minimal risk to the subjects. This protocol has received approval from the Institutional Review Board of Yale University (HIC: 1502015308), and a Health Insurance Portability and Accountability Act (HIPAA) Waiver of Authorisation has been granted to allow investigators to recruit subjects for the study. Findings will be disseminated through peer-reviewed, open-access scientific journals and conference presentations.

Immunology of HPV-mediated cervical cancer: current understanding

Human papilloma virus (HPV) has emerged as a primary cause of cervical cancer worldwide. HPV is a relatively small (55 nm in diameter) and non-enveloped virus containing approximately 8 kb long double stranded circular DNA genome. To date, 228 genotypes of HPV have been identified. Although all HPV infections do not lead to the development of malignancy of cervix, only persistent infection of high-risk types of HPV (mainly with HPV16 and HPV18) results in the disease. In addition, the immunity of the patients also acts as a key determinant in the carcinogenesis. Since, no HPV type specific medication is available for the patient suffering with cervical cancer, hence, a deep understanding of the disease etiology may be vital for developing an effective strategy for its prevention and management. From the immunological perspectives, the entire mechanisms of disease progression still remain unclear despite continuous efforts. In the present review, the recent developments in immunology of HPV-mediated cervix carcinoma were discussed. At the end, the prevention of disease using HPV type specific recombinant vaccines was also highlighted.

Effectiveness of 1, 2, and 3 Doses of Human Papillomavirus Vaccine Against High-Grade Cervical Lesions Positive for Human Papillomavirus 16 or 18

Before 2016, human papillomavirus (HPV) vaccination was recommended on a 3-dose schedule. However, many vaccine-eligible US females received fewer than 3 doses, which provided an opportunity to evaluate the real-world vaccine effectiveness (VE) of 1, 2, and 3 doses. We analyzed data on cervical intraepithelial neoplasia (CIN) grades 2-3 and adenocarcinoma in situ (designated CIN2+) from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT; 2008-2014). Archived tissue from CIN2+ lesions was tested for 37 types of HPV. Women were classified by number of doses received ≥24 months before CIN2+ detection. Using a test-negative design, VE was estimated as 1 minus the adjusted odds ratio from a logistic regression model that compared vaccination history for women whose lesions tested positive for HPV-16/18 (vaccine-type cases) with that for women who had all other CIN2+ lesions (controls). Among 3,300 women with available data on CIN2+, typing results, and vaccine history, 1,561 (47%) were HPV-16/18-positive, 136 (4%) received 1 dose of HPV vaccine, 108 (3%) received 2 doses, and 325 (10%) received 3 doses. Adjusted odds ratios for vaccination with 1, 2, and 3 doses were 0.53 (95% confidence interval (CI): 0.37, 0.76; VE = 47%), 0.45 (95% CI: 0.30, 0.69; VE = 55%), and 0.26 (95% CI: 0.20, 0.35; VE = 74%), respectively. We found significant VE against vaccine-type CIN2+ after 3 doses of HPV vaccine and lower but significant VE with 1 or 2 doses.

The factors associated with maternal consent to human papillomavirus vaccination among adolescents in Israel

Purpose: To evaluate the knowledge and attitudes toward the human papillomavirus (HPV) vaccine among mothers of 8th graders in Israel, and to determine the factors associated with maternal consent to the HPV vaccine.Methods: We conducted a cross-sectional study among mothers of 8th grade students in 27 schools in Haifa and Northern districts of Israel during the 2016-17 school year. Data were collected using a structured telephone questionnaire.Results: 313 mothers answered the questionnaire (response rate = 91.8%). The mean knowledge level score was low (3.96 points [out of 10] ±2.68). Knowledge level was positively associated with Jewish nationality, being secular in religious practice and higher education. The attitude mean score was low-moderate (11.22 points [out of 18] ± 5.01). Attitude score was positively associated with Arab nationality. No significant association was found between knowledge level and attitudes. According to multivariate analysis, mothers' consent to the HPV vaccine was associated with the knowledge level score (OR = 0.82; 95%CI 0.68-0.98), the attitude score (OR = 1.76; 95%CI 1.53-2.02) and nationality (OR = 27.86, 95%CI 3.41-227.56).Conclusions: The knowledge level and attitudes toward the HPV vaccine were found to be unsatisfactory with racial disparities between Arabs and Jews. Jewish mothers compared with Arab mothers, mothers with a higher knowledge level or less positive attitudes were less likely to consent to the vaccine. These findings could contribute toward adapting programs to the different Israeli sectors in order to improve the rates of HPV vaccine receipt among adolescents.

Clinical Controversies in Cervical Cancer Screening

Through the implementation of systematic cervical cancer screening in the mid-20th century, the United States and other developed countries have seen death rates from cervical cancer decreased by ≥70%.The purpose of this article is to address several of the most controversial issues associated with cervical cancer screening recommendations in light of historical and evolving data. In this article, we will explore the controversies around the age at which to initiate and exit screening, human papilloma virus testing alone as a primary screening approach, and the impact of human papilloma virus vaccination on cervical cancer rates.

Status of HPV vaccination among HPV-infected women aged 20-60 years with abnormal cervical cytology in South Korea: a multicenter, retrospective study

OBJECTIVES

Since 2007, human papillomavirus (HPV) vaccines have been administered for the prevention of cervical cancer in Korea. We investigated the status of HPV vaccination among HPV-infected adult women with abnormal cervical cytology before the introduction of National Immunization Program.

METHODS

From 2010 to 2016, HPV-positive women (age, 20-60 years) with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion (LSIL) were enrolled from five hospitals across Korea. Their HPV genotype, epidemiologic, and clinical data, including HPV vaccination history, were obtained. We compared the epidemiological characteristics and prevalence of HPV-16/18 genotypes between vaccinated and unvaccinated women.

RESULTS

Among the 1,300 women, approximately 26% had a history of vaccination. Vaccinated patients were significantly younger, unmarried, and had a higher education level than unvaccinated women. For HPV-vaccinated individuals by vaccine dose, there was a significant younger age at vaccination initiation (p=0.025), longer duration from HPV vaccination to Pap test date (p=0.001), and lower proportion of HPV-16/18 (p=0.028) in the women with three doses. There was a significantly lower prevalence of HPV-16/18 genotypes in women who were vaccinated at least 12 months prior than in unvaccinated women (adjusted prevalence ratio [aPR]=0.51; 95% confidence interval [CI]=0.29-0.88). For women with LSIL, the prevalence of the HPV-16/18 genotypes was significantly lower in women who were vaccinated more than 12 months prior than in unvaccinated women (aPR=0.35; 95% CI=0.13-0.96).

CONCLUSION

This study highlighted the status of HPV vaccination and the prevalence of HPV-16/18 genotypes among HPV-infected women with abnormal cervical cytology according to HPV vaccination. It provides preliminary information regarding the status of HPV vaccination among Korean adult women.

Cost-Effectiveness Analysis of Human Papillomavirus Vaccination in Adolescent Girls in Taiwan

Objective:

Three vaccines are available to Taiwanese young girls for cervical cancer (CC) prevention. Here we evaluate the cost-effectiveness of the two-dose (2D) AS04-adjuvanted HPV-16/18 vaccine (2D-AS04-HPV-16/18v)+screening compared with a screening programme alone, with 2D human papillomavirus 6/11/16/18 vaccine (2D-4vHPVv)+screening, and with 2D/three-dose (3D) human papillomavirus 6/11/16/18/31/33/45/52/58 vaccine (9vHPVv)+screening, for Taiwan universal mass vaccination.

Methods:

A static Markov cohort model simulated the natural history of human papillomavirus (HPV) infection and CC screening for a 12-year-old cohort of Taiwanese girls (N=120,000). The model ran in 1-year cycles over the cohort’s lifetime. Vaccine efficacy irrespective of HPV type was considered in the analysis for each vaccine. Input data were obtained from published literature, local databases, government reports and websites, and expert opinion. The analysis incorporated direct medical costs only, with an annual discount rate of 3.0%. The threshold was determined as 1 Gross Domestic Product per capita (New Taiwan dollar [NT$] 727,818; year 2016).

Results:

The 2D-AS04-HPV-16/18v+screening yielded 0.0365 quality-adjusted life year (QALY) gained at an additional cost of NT$ 5,770 per person compared with the screening programme alone. This resulted in an incremental cost-effectiveness ratio well below the threshold. Compared with 2D-4vHPVv+screening and 2D/3D-9vHPVv+screening, discounted results demonstrated additional QALYs gained at lower cost for 2D-AS04-HPV-16/18v+screening, making it dominant over both 2D-4vHPVv+screening and 2D/3D-9vHPVv+screening.

Conclusions:

Vaccinating Taiwanese girls with 2D-AS04-HPV-16/18v in addition to screening to prevent CC is cost-effective compared with using a screening programme alone and the dominant option compared with 2D-4vHPVv+screening and 2D/3D-9vHPVv+screening.

Development and validation of a method for human papillomavirus genotyping based on molecular beacon probes

We describe a new assaying system for the detection and genotyping of human papillomavirus (HPV) based on linear-after-the-exponential-PCR(LATE-PCR) and melting curve analysis. The 23 most prevalent HPV strains (types 6, 11, 16, 18, 31, 33, 35, 39, 42, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73, 81, 82, and 83) are assayed in two sealed reaction tubes within 2 h. Good sensitivity and specificity was evaluated by testing cloned HPV DNA and clinical samples. The detection limit was 5–500 copies/reaction depending on the genotype. No cross-reactivity was observed with the other HPV types that are not covered by our method or pathogens tested which were commonly found in female genital tract. When compared with the HPV GenoArray Diagnostic kit, the results from 1104 clinical samples suggest good overall agreement between the two methods,(98.37%, 95% CI: 97.44%–98.97%) and the kappa value was 0.954. Overall, this new HPV genotyping assay system presents a simple, rapid, universally applicable, sensitive, and highly specific detection methodology that should be useful for HPV detection and genotyping, therefore, is potentially of great value in clinical application.

Anticipating the Impact of Human Papillomavirus Vaccination on US Cervical Cancer Prevention Strategies

Cervical cancer prevention guidelines are benchmarked to risk of cervical precancer. In younger age cohorts, vaccination against high-risk types of human papillomavirus (HPV) has reduced HPV 16/18 prevalence and cervical intraepithelial neoplasia. Lower prevalence of precancer will impair the sensitivity of cytology and colposcopy, but negative predictive value will rise. Training and skills maintenance will become more difficult as abnormalities become less common. Primary screening with HPV assays will become more attractive but will require HPV genotyping as most positive HPV tests will reflect non-16/18 infections with lower oncogenicity. Screening will begin later and will occur at longer intervals. Colposcopy and treatment thresholds will become more stringent. Historical data sets will become inappropriate for guidelines development. As women immunized using nonavalent vaccine reach screening age, these trends will become still more pronounced.

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 varying number of doses and timing between doses of quadrivalent HPV vaccine against severe cervical lesions

BACKGROUND

Based on immunogenicity studies, a 2 dose HPV vaccination-schedule was recently recommended for girls younger than 15 years. We aimed to investigate the effectiveness of quadrivalent HPV (qHPV) vaccination against CIN2 or worse (CIN2+), by age at vaccination, number of doses, and to test whether optimal timing of 2 doses of qHPV vaccine can confer the same level of protection as the originally recommended three dose-schedule.

METHODS

A population-based cohort of all women aged 13-30 years, living in Denmark or Sweden during 2006-2013, was followed for qHPV vaccination status and first occurrence of CIN2+.

RESULTS

The study cohort comprised 2,253,561 women, of which 33% were vaccinated during follow-up, and 1.7% were diagnosed with CIN2+. Vaccination at ages 13-16 and 17-19 was associated with a reduced risk of CIN2+ after 3 doses (IRR = 0.23, 95% CI 0.11-0.49, and IRR = 0.65, 95% CI 0.41-1.03, respectively), compared to being unvaccinated. After 1 and 2 doses there was a reduced risk, but not statistically significant. Women vaccinated ages 13-16 with 2 doses, where time between first and second dose was 5 months or longer showed no difference in risk compared to 3 doses.

CONCLUSIONS

Women vaccinated with 3 doses of qHPV showed a reduced risk of CIN2+ if they were vaccinated before age 20, with a further reduced risk if vaccinated before age 17. Vaccination with 2 doses, with the second dose 5 months or longer after the first dose, did not yield an increased risk of CIN2+, compared to 3 doses.

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.

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.

Impact of Number of Human Papillomavirus Vaccine Doses on Genital Warts Diagnoses Among a National Cohort of U.S. Adolescents

BACKGROUND

The impact of fewer than 3 doses of human papillomavirus (HPV) vaccine on genital warts is uncertain.

METHODS

Using the Truven Health Analytics Marketscan administrative database, we compared rates of genital warts among women receiving 0, 1, 2, or 3 doses of HPV vaccine. Females aged 9 to 18 years on January 1, 2007, who were continuously enrolled in the database through December 31, 2013, were included. Patients were assigned an HPV dose state (0, 1, 2, or 3) based on the last recorded dose. The exposure period began on January 1, 2007, or the date of the final HPV dose, and lasted until the first diagnosis of genital warts or December 31, 2013. Multivariable Poisson regression was performed to determine the risk of genital warts associated with vaccine doses.

RESULTS

Among 387,906 subjects, mean age and exposure period were 14.73 and 5.64 years, respectively. The proportions of doses received were: 52.1%, 7.8%, 9.4%, and 30.7% for 0, 1, 2, and 3 doses, respectively. The rate of genital warts was 1.97/1000 person-years. Receipt of 0 or 1 dose was associated with more genital warts than 3 doses. The effectiveness of 2 doses following current Centers for Disease Control and Prevention guidelines was similar to 3 doses. The risk of genital warts rose with age.

CONCLUSIONS

Prevention of genital warts is higher with completion of 3 vaccine doses than with 1 dose, though 2-dose recommendations appear to provide similar protection. Prospective effectiveness studies of recommended 2-dose schedules against clinical endpoints including persistent infection, genital warts, and cervical dysplasia are necessary to ensure long-term protection of vaccinated cohorts.

Cancer Prevention: Lessons Learned and Future Directions

In this review, we address selected areas that are central to the state-of-the-art of cancer prevention science. The emphasis on prevention as a viable and critical approach to decreasing cancer mortality has gained traction in recent years, evidenced by its inclusion in the US Vice President's Cancer Initiative (also termed 'Moonshot'). Cancer prevention occurs by arresting, slowing down, or reversing the carcinogenic process before invasion into surrounding tissue or by avoiding or blocking causative exposure. An important challenge is to identify individuals who will benefit most from preventive interventions with the least possible harm. Preventive interventions range from avoiding known carcinogens (e.g., tobacco or asbestos) to intervening with anticarcinogenic strategies (behavioral modifications , such as diet and exercise; medications; nutritional agents; and vaccination against causative agents). Here, we focus on active intervention with measures involving pharmaceutical and immunological agents.

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.

Human papillomavirus vaccination: the population impact

We currently have the knowledge and experience to prevent much of human papillomavirus (HPV)-related disease burden globally. In many countries where prophylactic HPV vaccination programs have been adopted as highly effective public health programs with good vaccine coverage, we are already seeing, in real-world settings, reduction of vaccine-related HPV-type infections, genital warts and cervical pre-cancers with potential reductions in vulvar, vaginal and anal pre-cancers. Moreover, we are seeing a change in cervical screening paradigms, as HPV-based screening programs now have strong evidence to support their use as more sensitive ways to detect underlying cervical abnormalities, as compared with conventional cervical cytology. This article describes the impact of prophylactic vaccination on these outcomes and in settings where these vaccines have been implemented in national immunisation programs. Given the successes seen to date and the availability of essential tools, there has been a global push to ensure that every woman has access to effective cervical screening and every girl has the opportunity for primary prevention through vaccination. A gender-neutral approach by offering vaccination to young boys has also been adopted by some countries and is worthy of consideration given that HPV-related cancers also affect males. Furthermore, vaccination of young boys has the advantage of reducing the risk of HPV transmission to sexual partners, lowering the infectious pool of HPV in the general population and ultimately HPV-related diseases for both genders. Therefore, it is appropriate that all countries consider and promote national guidelines and programs to prevent HPV-related diseases.

Comparison of HPV prevalence between HPV-vaccinated and non-vaccinated young adult women (20-26 years)

There is some concern about the effectiveness of the HPV vaccine among young adult women due to the risk of prior HPV infection. This study used National Health and Nutrition Examination Survey (NHANES) 2007-2012 data to evaluate the effectiveness of HPV vaccination among women 20-26 years of age who were vaccinated after 12 years of age. This cross-sectional study examined 878 young adult women (20-26 years) with complete information on HPV prevalence and HPV vaccination status from NHANES 2007-2012. Vaginal swab specimens were analyzed for HPV DNA by L1 consensus polymerase chain reaction followed by type-specific hybridization. Multivariate logistic regression models controlling for sociodemographic characteristics and sexual behaviors were used to compare type-specific HPV prevalence between vaccinated and unvaccinated women. A total of 21.4% of young adult women surveyed through NHANES between 2007 and 2012 received the HPV vaccine. Vaccinated women had a lower prevalence of vaccine types than unvaccinated women (7.4% vs 17.1%, prevalence ratio 0.43, 95% CI 0.21-0.88). The prevalence of high-risk nonvaccine types was higher among vaccinated women than unvaccinated women (52.1% vs 40.4%, prevalence ratio 1.29, 95% CI 1.06-1.57), but this difference was attenuated after adjusting for sexual behavior variables (adjusted prevalence ratio 1.19, 95% CI 0.99-1.43). HPV vaccination was effective against all 4 vaccine types in young women vaccinated after age 12. However, vaccinated women had a higher prevalence of high-risk nonvaccine types, suggesting that they may benefit from newer vaccines covering additional types.

The impact and cost-effectiveness of nonavalent HPV vaccination in the United States: Estimates from a simplified transmission model

INTRODUCTION

The objective of this study was to assess the incremental costs and benefits of the 9-valent HPV vaccine (9vHPV) compared with the quadrivalent HPV vaccine (4vHPV). Like 4vHPV, 9vHPV protects against HPV types 6, 11, 16, and 18. 9vHPV also protects against 5 additional HPV types 31, 33, 45, 52, and 58.

METHODS

We adapted a previously published model of the impact and cost-effectiveness of 4vHPV to include the 5 additional HPV types in 9vHPV. The vaccine strategies we examined were (1) 4vHPV for males and females; (2) 9vHPV for females and 4vHPV for males; and (3) 9vHPV for males and females. In the base case, 9vHPV cost $13 more per dose than 4vHPV, based on available vaccine price information.

RESULTS

Providing 9vHPV to females compared with 4vHPV for females (assuming 4vHPV for males in both scenarios) was cost-saving regardless of whether or not cross-protection for 4vHPV was assumed. The cost per quality-adjusted life year (QALY) gained by 9vHPV for both sexes (compared with 4vHPV for both sexes) was < $0 (cost-saving) when assuming no cross-protection for 4vHPV and $8,600 when assuming cross-protection for 4vHPV.

CONCLUSIONS

Compared with a vaccination program of 4vHPV for both sexes, a vaccination program of 9vHPV for both sexes can improve health outcomes and can be cost-saving.

Monitoring the impact of HPV vaccine in males-Considerations and challenges

In this article, we examine the issues involved if national or sub-national programs are considering extending post HPV vaccine introduction monitoring to include males. Vaccination programs are now being extended to include males in some countries, in order to improve population level HPV infection control and to directly prevent HPV-related disease in males such as anogenital warts and anal cancers. Coverage and adverse events surveillance are essential components of post-vaccination monitoring. Monitoring the impact of vaccination on HPV infection and disease in men raises some similar challenges to monitoring in females, such as the long time frame until cancer outcomes, and also different ones given that genital specimens suitable for monitoring HPV prevalence are not routinely collected for other diagnostic or screening purposes in males. Thus, dedicated surveillance strategies must be designed; the framework of these may be country-specific, dependent upon the male population that is offered vaccination, the health care infrastructure and existing models of disease surveillance such as STI networks. The primary objective of any male HPV surveillance program will be to document changes in the prevalence of HPV infection and disease due to vaccine targeted HPV types occurring post vaccination. The full spectrum of outcomes to be considered for inclusion in any surveillance plan includes HPV prevalence monitoring, anogenital warts, potentially pre-cancerous lesions such as anal squamous intraepithelial lesions (SIL), and cancers. Ideally, a combination of short term and long term outcome measures would be included. Surveillance over time in specific targeted populations of men who have sex with men and HIV-infected men (populations at high risk for HPV infection and associated disease) could be an efficient use of resources to demonstrate impact.

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Males surveillance can provide information about both herd protection and direct impact.

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Dedicated specimen collection is needed for HPV prevalence surveillance in males.

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Anogenital wart monitoring is a useful early indicator of HPV vaccine impact.

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Trends in HPV-related male cancers will be the ultimate indicator of success.

Monitoring Effect of Human Papillomavirus Vaccines in US Population, Emerging Infections Program, 2008-2012

Methods for surveillance of cervical precancers and associated types were developed to monitor effect of HPV vaccination.

In 2007, five Emerging Infections Program (EIP) sites were funded to determine the feasibility of establishing a population-based surveillance system for monitoring the effect of human papillomavirus (HPV) vaccine on pre-invasive cervical lesions. The project involved active population-based surveillance of cervical intraepithelial neoplasia grades 2 and 3 and adenocarcinoma in situ as well as associated HPV types in women >18 years of age residing in defined catchment areas; collecting relevant clinical information and detailed HPV vaccination histories for women 18–39 years of age; and estimating the annual rate of cervical cancer screening among the catchment area population. The first few years of the project provided key information, including data on HPV type distribution, before expected effect of vaccine introduction. The project’s success exemplifies the flexibility of EIP’s network to expand core activities to include emerging surveillance needs beyond acute infectious diseases. Project results contribute key information regarding the impact of HPV vaccination in the United States.

Evaluation of safety and immunogenicity of a quadrivalent human papillomavirus vaccine in healthy females between 9 and 26 years of age in Sub-Saharan Africa

Due to sporadic and not easily accessible cervical cancer screening, human papillomavirus (HPV)-related cervical cancer is a leading cause of cancer death in Sub-Saharan African women. This study was designed to assess the safety and immunogenicity of a quadrivalent human papillomavirus (qHPV) vaccine in sub-Saharan African women. This seven month, double-blind study enrolled 250 healthy, human immunodeficiency virus (HIV)-uninfected females ages 9-26 residing in Ghana, Kenya, and Senegal. Thirty females ages 13-15 and 120 females ages 16-26 received qHPV vaccine. In addition, 100 females ages 9-12 y were randomized in a 4:1 ratio to receive either qHPV vaccine (n = 80) or placebo (n = 20 ). The primary immunogenicity hypothesis was that an acceptable percentage of subjects who received the qHPV vaccine seroconvert to HPV6/11/16/18 at 4 weeks post-dose 3, defined as the lower bound of the corresponding 95% confidence interval (CI) exceeding 90%. The primary safety objective was to demonstrate that qHPV vaccine was generally well tolerated when administered in a 3-dose regimen. The pre-specified statistical criterion for the primary immunogenicity hypothesis was met: the lower bound of the 95% exact binomial CI on the seroconversion rate was at least 98% for each vaccine HPV type and all subjects seroconverted by 4 weeks post-dose 3. Across vaccination groups, the most common adverse events (AE) were at the injection site, including pain, swelling, and erythema. No subject discontinued study medication due to an AE and no serious AEs were reported. There were no deaths. This study demonstrated that qHPV vaccination of sub-Saharan African women was highly immunogenic and generally well tolerated.

Quadrivalent HPV vaccine effectiveness against high-grade cervical lesions by age at vaccination: A population-based study

Human papillomavirus (HPV) types 16/18, included in HPV vaccines, contribute to the majority of cervical cancer, and a substantial proportion of cervical intraepithelial neoplasia (CIN) grades 2/3 or worse (CIN2+/CIN3+) including adenocarcinoma in situ or worse. The aim of this study was to quantify the effect of quadrivalent HPV (qHPV) vaccination on incidence of CIN2+ and CIN3+. A nationwide cohort of girls and young women resident in Sweden 2006–2013 and aged 13–29 (n = 1,333,691) was followed for vaccination and histologically confirmed high‐grade cervical lesions. Data were collected using the Swedish nationwide healthcare registers. Poisson regression was used to calculate incidence rate ratios (IRRs) and vaccine effectiveness [(1‐IRR)x100%] comparing fully vaccinated with unvaccinated individuals. IRRs were adjusted for attained age and parental education, and stratified on vaccination initiation age. Effectiveness against CIN2+ was 75% (IRR = 0.25, 95%CI = 0.18–0.35) for those initiating vaccination before age 17, and 46% (IRR = 0.54, 95%CI = 0.46–0.64) and 22% (IRR = 0.78, 95%CI = 0.65–0.93) for those initiating vaccination at ages 17–19, and at ages 20–29, respectively. Vaccine effectiveness against CIN3+ was similar to vaccine effectiveness against CIN2+. Results were robust for both women participating to the organized screening program and for women at prescreening ages. We show high effectiveness of qHPV vaccination on CIN2+ and CIN3+ lesions, with greater effectiveness observed in girls younger at vaccination initiation. Continued monitoring of impact of HPV vaccination in the population is needed in order to evaluate both long‐term vaccine effectiveness and to evaluate whether the vaccination program achieves anticipated effects in prevention of invasive cervical cancer.

What's new?

How well does quadrivalent HPV vaccination protect girls from cancer? These authors followed the entire population of Swedish girls ages 13–29 for high‐grade cervical lesions and quadrivalent HPV vaccination through a registry‐based study. Those receiving the quadrivalent HPV vaccine were less likely to develop of CIN2 and CIN3. In Sweden, the organized cervical screening program begins at age 23. This study showed that the vaccine was more effective against CIN2 and CIN3 if given before age 17 years. Longer follow‐up of vaccinated women is needed to determine the long‐term effectiveness of Sweden's vaccination program against invasive cervical cancer.

Incidence and incidence trends of the most frequent cancers in adolescent and young adult Americans, including "nonmalignant/noninvasive" tumors

BACKGROUND

Incidence rates and trends of cancers in adolescents and young adults (AYAs) ages 15 to 39 years were reexamined a decade after the US National Cancer Institute AYA Oncology Progress Review Group was established.

METHODS

Data from the Surveillance, Epidemiology, and End Results program through 2011 were used to ascertain incidence trends since the year 2000 of the 40 most frequent cancers in AYAs, including tumors with nonmalignant/noninvasive behavior.

RESULTS

Seven cancers in AYAs exhibited an overall increase in incidence; in 4, the annual percent change (APC) exceeded 3 (kidney, thyroid, uterus [corpus], and prostate cancer); whereas, in 3, the APC was between 0.7 and 1.4 (acute lymphoblastic leukemia and cancers of the colorectum and testis). Eight cancers exhibited statistically significant decreases in incidence among AYAs: Kaposi sarcoma (KS), fibromatous neoplasms, melanoma, and cancers of the anorectum, bladder, uterine cervix, esophagus, and lung, each with an APC less than -1. AYAs had a higher proportion of noninvasive tumors than either older or younger patients.

CONCLUSIONS

An examination of cancer incidence patterns in AYAs observed over the recent decade reveal a complex pattern. Thyroid cancer by itself accounts for most of the overall increase and is likely caused by overdiagnosis. Reductions in cervix and lung cancer, melanoma, and KS can be attributed to successful national prevention programs. A higher proportion of noninvasive tumors in AYAs than in children and older adults indicates a need to revise the current system of classifying tumors in this population.

Interventions to increase HPV vaccination coverage: A systematic review

We reviewed intervention studies designed to increase human papillomavirus (HPV) vaccination coverage to further understand the impact interventions can have on HPV vaccination coverage. We searched 5 databases for intervention studies published from June 2006 to May 2015. Studies were included if they quantitatively measured HPV vaccination coverage as an outcome and were conducted in the United States. We abstracted outcomes, methods, and results from each study and classified by type of intervention conducted. Findings from 34 studies suggest many types of intervention strategies can increase HPV vaccination coverage in different settings, and with modest cost. Interventions were effective especially when implemented in combination at both provider and community levels. However, not all interventions showed significant effects on coverage. More research is needed to identify the best methods for widespread implementation of effective strategies.

Cervical cancer screening of HPV vaccinated populations: Cytology, molecular testing, both or none

Cervical cancer control includes primary prevention through vaccination to prevent human papillomavirus (HPV) infection and secondary prevention through screening to detect and treat cervical precancerous lesions. This review summarizes the evidence for the population impact of vaccines against oncogenic HPV types in reducing the prevalence of cervical precancerous lesions. We examine the gradual shift in screening technology from cervical cytology alone to cytology and HPV cotesting, and finally to the recognition that HPV testing can serve alone as the new screening paradigm, particularly in the initial post-vaccination era. We should expect an impact on screening performance and practices, as cohorts of HPV-vaccinated girls and adolescents reach cervical cancer screening age. In preparation for changes in the screening paradigm for the vaccination era, we propose that policymaking on cervical cancer screening should mirror current practices with other cancers as benchmarks. Cervical precancerous lesions will become a very rare condition following the widespread implementation of HPV vaccines with broader coverage in the number of preventable oncogenic types. Irrespective of screening technology, the false positive results will far outnumber the true positive ones, a tipping point that will herald a new period when the harms from cervical cancer screening will outweigh its benefits. We present a conceptual framework to guide decision making when we reach this point within 25-30 years.

9-Valent HPV vaccine for cancers, pre-cancers and genital warts related to HPV

Human papillomavirus (HPV) is the causative agent of nearly all cervical cancer cases as well as a substantial proportion of anal, vulvar, vaginal, penile and oropharyngeal cancers, making it responsible for approximately 5% of the global cancer burden. The first-generation HPV vaccines that is, quadrivalent HPV type 6/11/16/18 vaccine and bivalent HPV type 16/18 vaccine were licensed in 2006 and 2007, respectively. A second-generation 9-valent HPV type 6/11/16/18/31/33/45/52/58 vaccine with broader cancer coverage was initiated even before the first vaccines were approved. By preventing HPV infection and disease due to HPV31/33/45/52/58, the 9vHPV vaccine has the potential to increase prevention of cervical cancer from 70 to 90%. In addition, the 9vHPV vaccine has the potential to prevent 85-95% of HPV-related vulvar, vaginal and anal cancers. Overall, the 9vHPV vaccine addresses a significant unmet medical need, although further health economics and implementation research is needed.

A Randomized, Double-Blind, Phase III Study of the Immunogenicity and Safety of a 9-Valent Human Papillomavirus L1 Virus-Like Particle Vaccine (V503) Versus Gardasil® in 9-15-Year-Old Girls

BACKGROUND

A 9-valent human papillomavirus (9vHPV) vaccine has been developed to prevent infections and diseases related to HPV 6/11/16/18 [as per the licensed quadrivalent HPV (qHPV) vaccine], as well as 5 additional oncogenic HPV types (HPV 31/33/45/52/58). Compared with the qHPV vaccine, the 9vHPV vaccine potentially increases the coverage of protection from 70% to 90% of cervical cancers. We compared the immunogenicity and safety of the 9vHPV vaccine versus the qHPV vaccine in 9-15-year-old girls.

METHODS

Participants (n = 600) were randomized to receive 9vHPV or qHPV vaccines on day 1, month 2 and month 6. Serology testing was performed on day 1 and month 7. HPV type-specific antibody titers (anti-HPV 6/11/16/18/31/33/45/52/58) were determined by competitive Luminex immunoassay and expressed as geometric mean titers and seroconversion rates. Vaccine safety was also assessed.

RESULTS

The HPV 6/11/16/18 immune responses elicited by the 9vHPV vaccine were comparable with those elicited by the qHPV vaccine. All participants (except 1 for HPV 45) receiving the 9vHPV vaccine seroconverted for HPV 31/33/45/52/58. The 9vHPV and qHPV vaccines showed comparable safety profiles, although the incidence of injection-site swelling was higher in the 9vHPV vaccine group.

CONCLUSIONS

In addition to immune responses to HPV 31/33/45/52/58, a 3-dose regimen of the 9vHPV vaccine elicited a similar immune response to HPV 6/11/16/18 when compared with the qHPV vaccine in girls aged 9-15 years. The safety profile was also similar for the 2 vaccines.

An Overview of Quadrivalent Human Papillomavirus Vaccine Safety: 2006 to 2015

BACKGROUND

A quadrivalent human papillomavirus (HPV4) type 6/11/16/18 vaccine (GARDASIL/SILGARD®) has been licensed in many countries around the world for the prevention of cervical, vulvar, vaginal, and anal cancers and precancers, as well as external genital warts causally related to HPV types 6/11/16/18. Across 7 phase 3 clinical trials involving more than 29,000 males and females ages 9-45 years, vaccination was generally well tolerated. Because of its expected public health benefit in reducing cervical cancer and other HPV-related diseases, the vaccine has been implemented in the national vaccination programs of several countries, with over 178 million doses distributed worldwide.

METHODS

Extensive efforts to assess the safety of the vaccine in routine practice have been conducted over the past 9 years since licensure, including more than 15 studies in more than 1 million preadolescents, adolescents and adults from various countries. Most have been performed in the general population although there have been some in special populations (pregnant women, HIV-infected individuals and those with systemic lupus erythematosus).

RESULTS

We present a summary of the published, postlicensure safety data from active and passive surveillance. Only syncope, and possibly skin infections were associated with vaccination in the postlicensure setting. Serious adverse events, such as adverse pregnancy outcomes, autoimmune diseases (including Guillain-Barre Syndrome and multiple sclerosis), anaphylaxis, venous thromboembolism and stroke, were extensively studied, and no increase in the incidence of these events was found compared with background rates.

CONCLUSIONS

These results, along with the safety data from the prelicensure clinical trials, confirm that the HPV4 vaccine has a favorable safety profile. Key policy, medical and regulatory organizations around the world have independently reviewed these data and continue to recommend routine HPV vaccination.

The efficacy and duration of vaccine protection against human papillomavirus: a systematic review and meta-analysis

BACKGROUND

The German Standing Committee on Vaccination (STIKO) recommends vaccination against human papillomaviruses (HPV) of the high-risk types 16 and 18. The duration of protection afforded by HPV vaccines has been reported in multiple studies to date but has not been systematically evaluated.

METHOD

Systematic literature review and meta-analysis on the efficacy of vaccination, with assessment of evidence by the GRADE criteria (Grading of Recommendations Assessment, Development and Evaluation).

RESULTS

15 studies were identified: 10 randomized controlled trials (RCTs) and 5 observational studies. The RCTs included a total of 46 436 participants. The duration of follow-up was short (median, 3 years) in 8 RCTs and long (median, 6 years) in 2 RCTs. During the period of short-term follow up, the pooled efficacy of vaccination for the study endpoint of incident HPV infection (percentage of infections prevented) was 83% (95% confidence interval [CI]: 70-90% ), while the pooled efficacy against persistent HPV infection was 90% (95% CI: 79-95% ). In this period, CIN 2+ lesions were prevented with 84% efficacy (95% CI: 50-95% ), and CIN 3+ lesions with 94% efficacy (95% CI: 83-98% ). During the period of long-term follow-up, incident infections were prevented with 94% efficacy (95% CI: 80-98% ) and persistent infections with 95% efficacy (95% CI: 84-99% ). The long-term efficacy against CIN 2+ lesions was 86% (95% CI: -166-99% ). No data are available on the long-term efficacy of vaccination against CIN 3+ lesions.

CONCLUSION

Long-term observation does not indicate any loss of antiviral protection after vaccination against HPV 16 and 18, although the evidence for long-term protection is of lesser quality than that for short-term protection.

Immunogenicity and Safety of a 9-Valent HPV Vaccine

OBJECTIVES

Prophylactic vaccination of youngwomen aged 16 to 26 years with the 9-valent (6/11/16/18/31/33/45/52/58) human papillomavirus (HPV) virus-like particle (9vHPV) vaccine prevents infection and disease. We conducted a noninferiority immunogenicity study to bridge the findings in young women to girls and boys aged 9 to 15 years.

METHODS

Subjects (N = 3066) received a 3-dose regimen of 9vHPV vaccine administered at day 1, month 2, and month 6. Anti-HPV serologic assays were performed at day 1 and month 7. Noninferiority required that the lower bound of 2-sided 95% confidence intervals of geometric mean titer ratios (boys:young women or girls:young women) be >0.67 for each HPV type. Systemic and injection-site adverse experiences (AEs) and serious AEs were monitored.

RESULTS

At 4 weeks after dose 3, >99% of girls, boys, and young women seroconverted for each vaccine HPV type. Increases in geometric mean titers to HPV types 6/11/16/18/31/33/45/52/58 were elicited in all vaccine groups. Responses in girls and boys were noninferior to those of young women. Persistence of anti-HPV responses was demonstrated through 2.5 years after dose 3. Administration of the 9vHPV vaccine was generally well tolerated. A lower proportion of girls (81.9%) and boys (72.8%) than young women (85.4%) reported injection-site AEs, most of which were mild to moderate in intensity.

CONCLUSIONS

These data support bridging the efficacy findings with 9vHPV vaccine in young women 16 to 26 years of age to girls and boys 9 to 15 years of age and implementing gender-neutral HPV vaccination programs in preadolescents and adolescents.

A cross-sectional study of high-risk human papillomavirus clustering and cervical outcomes in HIV-infected women in Rio de Janeiro, Brazil

Background

In Brazil, the rate of cervical cancer remains high despite the availability of screening programs. With ongoing vaccine development and implementation, information on the prevalence of specific HPV types is needed, particularly among high-risk populations, such as HIV-infected women.

Methods

We performed a study of HIV-infected women in Rio de Janeiro, Brazil, who underwent cervical HPV genotype testing between 2005-2013. We examined the prevalence of high-risk HPV types and the patterns of high-risk HPV type clustering. Using logarithmic binomial regression, we estimated the risk of abnormal cytology by HPV genotype result.

Results

Of the 562 women included, 498 (89 %) had at least one HPV type detected. 364 women (65 %) had at least one high-risk HPV type detected and 181 (32 %) had more than one high-risk type detected. HPV 58 was the most frequent HPV type detected overall (prevalence 19.8 % [95 % confidence interval 16.4–23.1]), followed by HPV 53 (prevalence 15.5 % [12.5–18.5]) and HPV 16 (prevalence 13 % [10.2–15.8]). Women infected with more than one high-risk HPV type were younger, had lower CD4+ lymphocyte counts, and were more likely to be infected with HPV 16 or 18. In adjusted analyses, presence of more than one high-risk HPV type was associated with a two-fold increased risk of abnormal cytology after adjusting for presence of individual high-risk type, age, and CD4+ lymphocyte count (adjusted prevalence ratios 1.88–2.07, all p <0.001). No single high-risk HPV type was statistically associated with abnormal cytology after adjusting for the presence of more than one high-risk HPV type.

Conclusions

In the largest study of cervical HPV genotypes among HIV-infected women in Latin America, infection by high-risk HPV types other than 16 or 18 and infection by more than one high-risk HPV types were common. Infection by more than one high-risk type was more strongly associated with abnormal cervical cytology than any individual high-risk HPV type, highlighting the need for multi-valent HPV vaccines.

Population-based trends in high-grade cervical lesions in the early human papillomavirus vaccine era in the United States

BACKGROUND

Cervical intraepithelial neoplasia grade 2, 3, and adenocarcinoma in situ (CIN2+) lesions can be monitored as early indicators of human papillomavirus (HPV) vaccine impact. Changes to screening utilization will affect observed reductions in CIN2+ rates and complicate the interpretation of vaccine impact.

METHODS

From 2008 to 2012, 9119 cases of CIN2+ among 18- to 39-year-old residents of catchment areas in California, Connecticut, New York, and Oregon were reported to the HPV-IMPACT Project, a sentinel system for monitoring the population impact of HPV vaccine. Age-stratified CIN2+ incidence rates were calculated for each catchment. Annual cervical screening was estimated for California, New York, and Oregon catchments with administrative and survey data. The Cochran-Armitage test was used to examine trends.

RESULTS

From 2008 to 2012, the incidence of CIN2+ significantly decreased among 18- to 20-year-olds (California, from 94 to 5 per 100,000 women; Connecticut, from 450 to 57 per 100,000 women; New York, from 299 to 43 per 100,000 women; and Oregon, from 202 to 37 per 100,000 women; Ptrend  < .0001) and among 21- to 29-year-olds in Connecticut (from 762 to 589 per 100,000 women) and New York (from 770 to 465 per 100,000 women; Ptrend  < .001); rates did not differ among 30- to 39-year-olds. During the same period, screening rates also declined, with the largest decreases among 18- to 20-year-olds (from 67% in Oregon to 88% in California) and with smaller declines among 21- to 29-year-olds (13%-27%) and 30- to 39-year-olds (3%-21%).

CONCLUSIONS

The declines in CIN2+ detection in young women were likely due to reduced screening but could also reflect the impact of vaccination. These data illustrate challenges in interpreting CIN2+ ecologic trends in the new era of cervical cancer prevention and emphasize the importance of information such as HPV types detected in lesions to assess the impact of HPV vaccine on cervical precancers.

EUROGIN 2014 roadmap: differences in human papillomavirus infection natural history, transmission and human papillomavirus-related cancer incidence by gender and anatomic site of infection

Human papillomaviruses (HPVs) cause cancer at multiple anatomic sites in men and women, including cervical, oropharyngeal, anal, vulvar and vaginal cancers in women and oropharyngeal, anal and penile cancers in men. In this EUROGIN 2014 roadmap, differences in HPV-related cancer and infection burden by gender and anatomic site are reviewed. The proportion of cancers attributable to HPV varies by anatomic site, with nearly 100% of cervical, 88% of anal and <50% of lower genital tract and oropharyngeal cancers attributable to HPV, depending on world region and prevalence of tobacco use. Often, mirroring cancer incidence rates, HPV prevalence and infection natural history varies by gender and anatomic site of infection. Oral HPV infection is rare and significantly differs by gender; yet, HPV-related cancer incidence at this site is several-fold higher than at either the anal canal or the penile epithelium. HPV seroprevalence is significantly higher among women compared to men, likely explaining the differences in age-specific HPV prevalence and incidence patterns observed by gender. Correspondingly, among heterosexual partners, HPV transmission appears higher from women to men. More research is needed to characterize HPV natural history at each anatomic site where HPV causes cancer in men and women, information that is critical to inform the basic science of HPV natural history and the development of future infection and cancer prevention efforts.

Immunizing adolescents: a selected review of recent literature and US recommendations

PURPOSE OF REVIEW

To provide a clinically relevant synopsis of the latest research and recommendations regarding adolescent immunizations.

RECENT FINDINGS

Immunization is an important and effective strategy for preventing morbidity and mortality in adolescents. Although there has been progress in recent years, coverage rates in the US remain suboptimal, particularly for the human papillomavirus vaccine. Much work has been done to better understand and address the barriers to adolescent immunization, so that all teens may be protected against serious vaccine-preventable diseases. In addition, several recent studies have focused on the effectiveness of current adolescent vaccines and the development of new vaccines to protect against additional types of human papillomavirus and serotype B Neisseria meningitidis. Decreased pertussis vaccine effectiveness has led to new recommendations for pregnant women, including adolescents, to protect them and their young infants. The present review highlights selected literature on acellular pertussis, meningococcal, and human papillomavirus vaccines. Research findings on various strategies to improve adolescent vaccine uptake are also discussed in this review.

SUMMARY

Research on adolescent immunizations and their delivery continues to have an impact on clinical practice and will shape future guidelines. Through this work, we can learn how best to protect adolescents against vaccine-preventable diseases.

An open-label, randomized study of a 9-valent human papillomavirus vaccine given concomitantly with diphtheria, tetanus, pertussis and poliomyelitis vaccines to healthy adolescents 11-15 years of age

BACKGROUND

A 9-valent human papillomavirus (9vHPV) vaccine has recently been reported to be safe and highly efficacious against infection and disease related to HPV6/11/16/18/31/33/45/52/58. We evaluated the immunogenicity and safety of the 9vHPV vaccine administered concomitantly with REPEVAX (diphtheria, tetanus, acellular pertussis and inactivated poliomyelitis vaccine).

METHODS

This open-label, randomized, multicenter study enrolled 1054 males and females ages 11-15 years. Subjects were randomly assigned to each group in a 1:1 ratio. Subjects received a 0.5 mL dose of 9vHPV vaccine intramuscularly at day 1, months 2 and 6 and a 0.5 mL dose of REPEVAX either on day 1 (concomitant vaccination group; n = 526) or at month 1 (nonconcomitant vaccination group, n = 528). Serologic responses for each vaccine component were tested by 1-sided tests of noninferiority between groups. Systemic and injection-site adverse experiences (AEs) and serious AEs were monitored.

RESULTS

Noninferiority of anti-HPV geometric mean titers and seroconversion rates for all 9vHPV antigens were demonstrated for the concomitant group compared with the nonconcomitant group. Seroconversion rates for the 9vHPV vaccine types were ≥99.8% in both groups at month 7. For REPEVAX, noninferiority of immune response was established for diphtheria, tetanus, all polio and pertussis antigens for both groups. There were no vaccine-related serious AEs.

CONCLUSION

Overall, concomitant administration of 9vHPV vaccine and REPEVAX was generally well tolerated and did not interfere with the immune response to either vaccine. This strategy would minimize the number of visits required to deliver each vaccine individually.

Present status of human papillomavirus vaccine development and implementation

Oncogenic human papillomavirus (HPV) infection is the cause of nearly all cervical cancers and a proportion of other anogenital and oropharyngeal cancers. A bivalent vaccine containing HPV 16 and 18 and a quadrivalent vaccine containing HPV 6, 11, 16, and 18 antigens are in use in vaccination programmes around the world. In clinical trials, three vaccine doses provided 90-100% protection against cervical infection and pre-cancer related to HPV 16 and 18 in women aged 15-26 years who were not infected at vaccination. Partial cross-protection against other HPV types has been reported but its duration is unknown. The vaccines were also efficacious at the prevention of HPV 16 and 18 infections at other anatomical sites in both sexes. Immunobridging studies allowed licensing of the vaccines for use starting at age 9 years for both sexes. Two-dose schedules elicit high antibody concentrations, leading to the recommendation of two-dose schedules for girls aged 9-14 years. Pre-licensure and post-licensure studies have provided data supporting vaccine safety. In 2014, a nonavalent vaccine containing HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58 antigens was licensed by the US Food and Drug Administration. HPV vaccination was first introduced in high-income countries owing to vaccine cost, logistic challenges, and competing health priorities. Since 2011, vaccine prices have lowered, allowing the introduction of the vaccine in some middle-income countries. Funding of the vaccine by the GAVI Alliance in 2012 led to demonstration projects in some low-income countries. By 2014, more than 57 countries had included the HPV vaccine in their national health programmes. Data from several countries have shown the effect of vaccination on HPV infection and associated disease, and provided evidence of herd immunity. Expansion of programmes to countries with the highest burden of disease is beginning, but further efforts are needed to realise the potential of HPV vaccines.

Design of a large outcome trial for a multivalent human papillomavirus L1 virus-like particle vaccine

BACKGROUND

The 9-valent human papillomavirus (HPV) (9vHPV) vaccine targets the four HPV types (6/11/16/18) covered by the licensed quadrivalent HPV (qHPV) vaccine and five additional types (31/33/45/52/58). A large outcome trial of 9vHPV vaccine was conducted.

METHODS

An active control (qHPV vaccine) was used because a placebo is not ethically acceptable. Since qHPV vaccine is (and 9vHPV vaccine was anticipated to be) highly efficacious against HPV 6/11/16/18, low incidence of HPV 6/11/16/18-associated disease was expected. Consequently, an efficacy comparison of 9vHPV versus qHPV vaccine for HPV 6/11/16/18 would have been prohibitively large in size. Moreover, no minimum antibody level predicting protection against infection or disease is defined for HPV vaccination. As an alternative approach, the two vaccines were compared using immunogenicity bridging for HPV 6/11/16/18 and clinical efficacy for HPV 31/33/45/52/58.

RESULTS

The two co-primary objectives were to demonstrate: (1) non-inferior anti-HPV 6/11/16/18 antibody response; and (2) superior efficacy in HPV 31/33/45/52/58-related clinical outcome, for 9vHPV vaccine versus qHPV vaccine. For HPV 6/11/16/18, supportive analyses included a non-inferiority assessment of the percent risk reduction (compared to historical placebo) for 9vHPV versus qHPV vaccine.

CONCLUSIONS

A Phase III study of 9vHPV vaccine was successfully implemented. Experience from this study design may be applicable when developing a multivalent vaccine covering the same serotypes as an existing vaccine plus additional serotypes and there is no immune correlate of protection. Also, this study established that efficacy of a new HPV vaccine may be demonstrated using immunogenicity endpoints, which may open new options in HPV vaccine development.

The next steps in cervical screening

Cervical cancer is fourth most common cancer among women with four-fifths of the global burden in low- and middle-income countries (LMICs). Persistent infection with one of the high-risk types of human papillomaviruses (HPV), particularly HPV 16/18, is the central cause of cervical neoplasia. Progress in developing feasible, alternative screening methods in LMICs and HPV vaccines have further improved cervical cancer prevention prospects. While existing screening programs in high-income countries should be re-organized, in view of the downstream effects of national HPV vaccination programs, LMICs should introduce national programs to vaccinate single year cohorts of girls aged 9-13 years with two or three doses and screen 30-35-year-old women with HPV testing to pragmatically decrease their high disease burden.

A 9-valent HPV vaccine against infection and intraepithelial neoplasia in women

BACKGROUND

The investigational 9-valent viruslike particle vaccine against human papillomavirus (HPV) includes the HPV types in the quadrivalent HPV (qHPV) vaccine (6, 11, 16, and 18) and five additional oncogenic types (31, 33, 45, 52, and 58). Here we present the results of a study of the efficacy and immunogenicity of the 9vHPV vaccine in women 16 to 26 years of age.

METHODS

We performed a randomized, international, double-blind, phase 2b-3 study of the 9vHPV vaccine in 14,215 women. Participants received the 9vHPV vaccine or the qHPV vaccine in a series of three intramuscular injections on day 1 and at months 2 and 6. Serum was collected for analysis of antibody responses. Swabs of labial, vulvar, perineal, perianal, endocervical, and ectocervical tissue were obtained and used for HPV DNA testing, and liquid-based cytologic testing (Papanicolaou testing) was performed regularly. Tissue obtained by means of biopsy or as part of definitive therapy (including a loop electrosurgical excision procedure and conization) was tested for HPV.

RESULTS

The rate of high-grade cervical, vulvar, or vaginal disease irrespective of HPV type (i.e., disease caused by HPV types included in the 9vHPV vaccine and those not included) in the modified intention-to-treat population (which included participants with and those without prevalent infection or disease) was 14.0 per 1000 person-years in both vaccine groups. The rate of high-grade cervical, vulvar, or vaginal disease related to HPV-31, 33, 45, 52, and 58 in a prespecified per-protocol efficacy population (susceptible population) was 0.1 per 1000 person-years in the 9vHPV group and 1.6 per 1000 person-years in the qHPV group (efficacy of the 9vHPV vaccine, 96.7%; 95% confidence interval, 80.9 to 99.8). Antibody responses to HPV-6, 11, 16, and 18 were noninferior to those generated by the qHPV vaccine. Adverse events related to injection site were more common in the 9vHPV group than in the qHPV group.

CONCLUSIONS

The 9vHPV vaccine prevented infection and disease related to HPV-31, 33, 45, 52, and 58 in a susceptible population and generated an antibody response to HPV-6, 11, 16, and 18 that was noninferior to that generated by the qHPV vaccine. The 9vHPV vaccine did not prevent infection and disease related to HPV types beyond the nine types covered by the vaccine. (Funded by Merck; ClinicalTrials.gov number, NCT00543543).

Reduction in HPV 16/18-associated high grade cervical lesions following HPV vaccine introduction in the United States - 2008-2012

BACKGROUND

Prevention of pre-invasive cervical lesions is an important benefit of HPV vaccines, but demonstrating impact on these lesions is impeded by changes in cervical cancer screening. Monitoring vaccine-types associated with lesions can help distinguish vaccine impact from screening effects. We examined trends in prevalence of HPV 16/18 types detected in cervical intraepithelial neoplasia 2, 3, and adenocarcinoma in situ (CIN2+) among women diagnosed with CIN2+ from 2008 to 2012 by vaccination status. We estimated vaccine effectiveness against HPV 16/18-attributable CIN2+ among women who received ≥1 dose by increasing time intervals between date of first vaccination and the screening test that led to detection of CIN2+ lesion.

METHODS

Data are from a population-based sentinel surveillance system to monitor HPV vaccine impact on type-specific CIN2+ among adult female residents of five catchment areas in California, Connecticut, New York, Oregon, and Tennessee. Vaccination and cervical cancer screening information was retrieved. Archived diagnostic specimens were obtained from reporting laboratories for HPV DNA typing.

RESULTS

From 2008 to 2012, prevalence of HPV 16/18 in CIN2+ lesions statistically significantly decreased from 53.6% to 28.4% among women who received at least one dose (Ptrend<.001) but not among unvaccinated women (57.1% vs 52.5%; Ptrend=.08) or women with unknown vaccination status (55.0% vs 50.5%; Ptrend=.71). Estimated vaccine effectiveness for prevention of HPV 16/18-attributable CIN2+ was 21% (95% CI: 1-37), 49% (95% CI: 28-64), and 72% (95% CI: 45-86) in women who initiated vaccination 25-36 months, 37-48 months, and >48 months prior to the screening test that led to CIN2+ diagnosis.

CONCLUSIONS

Population-based data from the United States indicate significant reductions in CIN2+ lesions attributable to types targeted by the vaccines and increasing HPV vaccine effectiveness with increasing interval between first vaccination and earliest detection of cervical disease.