Evaluation of Type Replacement Following HPV16/18 Vaccination: Pooled Analysis of Two Randomized Trials

Prevalence of Human Papillomavirus (HPV) and HPV Type Distribution in Penile Samples in Young Men in Denmark: Results 10 Years After Implementation of a Girls-Only HPV Vaccination Program

BACKGROUND

In Denmark, a girls-only human papillomavirus (HPV) vaccination program was initiated in 2008-2009. The study aim was to assess the HPV prevalence and type distribution in younger men prior to HPV vaccination in men.

METHODS

The study population was younger men who attended information days regarding military service. At random days (2019-2020), 280 men were included. We collected questionnaire data regarding risk factors for HPV infection and a penile swab for HPV testing. We compared results in this study with those from a previous study of young men (2006-2007).

RESULTS

The majority of participants (94%) were 18-20 years old. The median number of lifetime sexual partners was 4. Altogether, 130 men (46.4%) were HPV positive. No infections with HPV types 6, 11, 16, 18, 31, and 45 were detected. The most frequent type was HPV-51 (detected in 11.1%). Comparison showed that the odds of high-risk HPV type infection were higher in 2019-2020 (prevalence odds ratio [POR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) compared with 2006-2007. In contrast, the odds were lower (POR, 0.3 [95% CI, .1-.6]) for HPV types targeted by the 9-valent HPV vaccine.

CONCLUSIONS

The multicohort girls-only vaccination program has to a large degree protected young men against the HPV types included in the licensed vaccines. This does not speak against gender-neutral vaccination as the HPV prevalence is still high, although consisting largely of less carcinogenic HPV types.

Betapapillomavirus natural history and co-detection with alphapapillomavirus in cervical samples of adult women

Human papillomaviruses (HPV) of the genus Betapapillomavirus can infect both cutaneous and mucosal sites, but research on their natural history at mucosal sites remains scarce. We examined the risk factors and co-detection patterns of HPVs of the Betapapillomavirus and Alphapapillomavirus genera in cervical samples of the Ludwig-McGill cohort study. We assessed a subset of 505 women from the Ludwig-McGill cohort study from São Paulo, Brazil. Cervical samples over the first year of follow-up were tested for DNA of over 40 alphapapillomavirus types and 43 betapapillomavirus types using a type-specific multiplex genotyping polymerase chain reaction assay. We assessed the risk factors for prevalent and incident betapapillomavirus type detection, and whether types were detected more frequently together than expected assuming independence using permutation tests, logistic regression, and Cox regression. We observed significant within-genus clustering but not cross-genus clustering. Multiple betapapillomavirus types were co-detected in the same sample 2.24 (95% confidence interval [CI]: 1.65-3.29) times more frequently than expected. Conversely, co-detections of alphapapillomavirus and betapapillomavirus types in the same sample occurred only 0.64 (95% CI: 0.51-0.83) times as often as expected under independence. In prospective analyses, positivity to one HPV genus was associated with a nonsignificant lower incidence of detection of types in the other genus. Lifetime number of sex partners and new sex partner acquisition were associated with lower risks of prevalent and incident betapapillomavirus detection. Betapapillomaviruses are commonly found in the cervicovaginal tract. Results suggest potentially different mechanisms of transmission for betapapillomavirus genital infections other than vaginal sex.

Harnessing the post-vaccination era: Do emerging HPV types represent a new threat?

While the HPV vaccine is highly effective, it is unknown whether other, untargeted viral types could occupy empty niches to become an emerging threat. In this issue of Cell Host & Microbe, Pimenoff and colleagues present a community-level epidemiological analysis of HPV types up to 8 years after different vaccination policies.

The Distribution of Cervical Human Papillomavirus Infection Among Chinese Adult Women

Background

The characteristics and genotypic distribution of human papillomavirus (HPV) infection differ in different countries and regions. The purpose of this study was to analyze the distribution of 27 HPV subtypes among adult women receiving health examinations in Jinan, China.

Methods

A retrospective analysis was performed to analyze HPV subtype infection among adult women who underwent cervical cancer screening from January 1, 2020, to December 31, 2020.

Results

Among 4746 women receiving HPV testing, 682 cases were positive, representing 14.4% of patients. In total, 514 cases were infected by a single HPV subtype (75.4%), 115 cases had dual infections (16.9%), and 53 cases had multiple infections (7.7%). Among the 682 cases of HPV infection, 503 cases (73.8%) were high-risk HPV infections. The most common high-risk HPV strains were HPV 52 (23.3%), HPV 16 (13.5%), and HPV 58 (12.7%). Low-risk HPV strains infected 179 cases (26.2%). The most common genotypes were HPV 61 (25.7%), HPV 81 (21.2%), and HPV 55 (15.6%).

Conclusion

The HPV infection rate in healthy women was high, and the mixed infection rate was as high as 24.6%, highlighting the need for increased attention to this virus.

High vaccine effectiveness persists for ten years after HPV16/18 vaccination among young Dutch women

The current study describes the long-term effectiveness of three-dose HPV16/18 vaccination among Dutch women who were eligible for vaccination during a catch-up campaign and were followed in an observational cohort study. Ten years post vaccination, vaccine effectiveness (VE) was estimated using generalized estimating equation models. VE against persistent infections with vaccine type infections (HPV16/18) was high at 95.8%. For cross protective type persistent infections (HPV31/33/45) this was 64.6%. There were no indications of waning of protection over time. This indicates solid long-term protection is provided by the vaccine and is promising with regard to the future clinical impact.

High Prevalence of HPV 51 in an Unvaccinated Population and Implications for HPV Vaccines

Human papillomavirus (HPV) is detected in 99.7% of cervical cancers. Current vaccines target types 16 and 18. Prior to vaccination implementation, a prospective cohort study was conducted to determine baseline HPV prevalence in unvaccinated women in Wales; after HPV16 and HPV18, HPV 51 was found to be most prevalent. This study aimed to re-assess the unexpected high prevalence of HPV 51 and consider its potential for type-replacement. Two hundred HPV 51 positive samples underwent re-analysis by repeating the original methodology using HPV 51 GP5+/6+ PCR-enzyme immunoassay, and additionally a novel assay of HPV 51 E7 PCR. Data were correlated with age, social deprivation and cytology. Direct repeat of HPV 51 PCR-EIA identified 146/195 (75.0%) samples as HPV 51 positive; E7 PCR identified 166/195 (85.1%) samples as HPV 51 positive. HPV 51 prevalence increased with cytological grade. The prevalence of HPV 51 in the pre-vaccinated population was truly high. E7 DNA assays may offer increased specificity for HPV genotyping. Cross-protection of current vaccines against less-prevalent HPV types warrants further study. This study highlights the need for longitudinal investigation into the prevalence of non-vaccine HPV types, especially those phylogenetically different to vaccine types for potential type-replacement. Ongoing surveillance will inform future vaccines.

Precancerous cervical lesions caused by non-vaccine-preventable HPV types after vaccination with the bivalent AS04-adjuvanted HPV vaccine: an analysis of the long-term follow-up study from the randomised Costa Rica HPV Vaccine Trial

BACKGROUND

In women vaccinated against human papillomavirus (HPV), reductions in cervical disease and related procedures results in more women having intact transformation zones, potentially increasing the risk of cervical lesions caused by non-vaccine-preventable HPV types, a phenomenon termed clinical unmasking. We aimed to evaluate HPV vaccine efficacy against cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and cervical intraepithelial neoplasia grade 3 or worse (CIN3+) attributed to non-preventable HPV types in the long-term follow-up phase of the Costa Rica HPV Vaccine Trial (CVT).

METHODS

CVT was a randomised, double-blind, community-based trial done in Costa Rica. Eligible participants were women aged 18-25 years who were in general good health. Participants were randomly assigned (1:1) to receive an HPV 16 and 18 AS04-adjuvanted vaccine or control hepatitis A vaccine, using a blocked randomisation method (permuted block sizes of 14, 16, and 18). Vaccines in both groups were administered intramuscularly with 0·5 mL doses at 0, 1, and 6 months. Masking of vaccine allocation was maintained throughout the 4-year randomised trial phase, after which participants in the hepatitis A virus vaccine control group were provided the HPV vaccine and exited the study; a screening-only, unvaccinated control group was enrolled. The unvaccinated control group and HPV vaccine group were followed up for 7 years, during which treatment allocation was not masked. One of the prespecified primary endpoints for the long-term follow-up phase was precancers associated with HPV types not prevented by the vaccine, defined as histologically confirmed incident CIN2+ events or CIN3+ events attributed to any HPV type except HPV 16, 18, 31, 33, and 45. Our primary analytical period was years 7-11. Primary analyses were in all participants with at least one follow-up visit and excluded participants with a previous endpoint (ie, modified intention-to-treat cohort). Safety endpoints have been reported elsewhere. This trial is registered with ClinicalTrials.gov, NCT00128661 and NCT00867464. The randomised, masked trial phase is completed; an unmasked subset of women in the HPV-vaccinated group is under active investigation.

FINDINGS

Between June 28, 2004, and Dec 21, 2005, 7466 participants were enrolled (HPV vaccine group n=3727 and hepatitis A virus vaccine control group n=3739). Between March 30, 2009, and July 5, 2012, 2836 women enrolled in the new unvaccinated control group. The primary analytical cohort (years 7 to 11) included 2767 participants in the HPV vaccine group and 2563 in the unvaccinated group for the CIN2+ events endpoint assessment and 2826 participants in the HPV vaccine group and 2592 in the unvaccinated control group for the CIN3+ events endpoint assessment. Median follow-up during years 7 to 11 for women included for the CIN2+ events analysis was 52·8 months (IQR 44·0 to 60·7) for the HPV vaccine group and 49·8 months (42·0 to 56·9) for the unvaccinated control group. During years 7 to 11, clinical unmasking was observed with a negative vaccine efficacy against CIN2+ events attributed to non-preventable HPV types (-71·2% [95% CI -164·0 to -12·5]), with 9·2 (95% CI 2·1 to 15·6) additional CIN2+ events attributed to non-preventable HPV types per 1000 HPV-vaccinated participants versus HPV-unvaccinated participants. 27·0 (95% CI 14·2 to 39·9) fewer CIN2+ events irrespective of HPV type per 1000 vaccinated participants were observed during 11 years of follow-up. Vaccine efficacy against CIN3+ events attributed to non-preventable HPV types during years 7 to 11 was -135·0% (95% CI -329·8 to -33·5), with 8·3 (3·0 to 12·8) additional CIN3+ events attributed to non-preventable HPV types per 1000 vaccinated participants versus unvaccinated participants.

INTERPRETATION

Higher rates of CIN2+ events and CIN3+ events due to non-preventable HPV types in vaccinated versus unvaccinated participants suggests clinical unmasking could attenuate long-term reductions in high-grade disease following successful implementation of HPV vaccination programmes in screened populations. Importantly, the net benefit of vaccination remains considerable; therefore, HPV vaccination should still be prioritised as primary prevention for cervical cancer.

FUNDING

National Cancer Institute and National Institutes of Health Office of Research on Women's Health.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Viral Causality of Human Cancer and Potential Roles of Human Endogenous Retroviruses in the Multi-Omics Era: An Evolutionary Epidemiology Review

Being responsible for almost 12% of cancers worldwide, viruses are among the oldest known and most prevalent oncogenic agents. The quality of the evidence for the in vivo tumorigenic potential of microorganisms varies, thus accordingly, viruses were classified in 4 evidence-based categories by the International Agency for Research on Cancer in 2009. Since then, our understanding of the role of viruses in cancer has significantly improved, firstly due to the emergence of high throughput sequencing technologies that allowed the “brute-force” recovery of unknown viral genomes. At the same time, multi-omics approaches unravelled novel virus-host interactions in stem-cell biology. We now know that viral elements, either exogenous or endogenous, have multiple sometimes conflicting roles in human pathophysiology and the development of cancer. Here we integrate emerging evidence on viral causality in human cancer from basic mechanisms to clinical studies. We analyze viral tumorigenesis under the scope of deep-in-time human-virus evolutionary relationships and critically comment on the evidence through the eyes of clinical epidemiology, firstly by reviewing recognized oncoviruses and their mechanisms of inducing tumorigenesis, and then by examining the potential role of integrated viruses in our genome in the process of carcinogenesis.

Characterization of HPV subtypes not covered by the nine-valent vaccine in patients with CIN 2-3 and cervical squamous cell carcinoma

BACKGROUND

As the second most common female malignant tumor, cervical cancer is also one of the most preventable and avoidable cancers. The World Health Organization has launched a global plan to accelerate the elimination of cervical cancer. Therefore, in the era of postvaccine, the role of HPV subtypes in cervical precancerous lesions and cervical cancer that are not covered by vaccine should be further discussed. The purpose of this study was to explore the role of HPV subtypes not covered by the nine-valent vaccine in high-grade cervical precancerous lesions and cervical cancer.

MATERIALS AND METHODS

A retrospective analysis was performed on the clinical data of 5220 patients with an HPV infection who were diagnosed and treated in the Department of Gynecology of Shanghai General Hospital between October 2016 and February 2020. In addition, the clinical characteristics of the biopsy results of 470 cases of cervical intraepithelial neoplasia (CIN) 2-3 and 205 cases of cervical squamous cell carcinoma were analyzed.

RESULTS

Among patients with HPV subtype infection not covered by the nine-valent vaccine, univariate analysis showed that compared with patients with CIN 2-3, age ≥ 50, not using condom and TCT reported as ASC-H were risk factors for cervical squamous cell carcinoma (P < 0.05). The detection rates of HPV subtype not covered by the nine-valent vaccine in CIN 2-3 and cervical squamous cell carcinoma patients were 7.23% and 6.34%, respectively.

CONCLUSION

In patients with CIN 2-3 and cervical squamous cell carcinoma, the infection rates of HPV subtype not covered by the nine-valent vaccine were 7.23% and 6.34%, respectively. With the increasing popularity of the vaccine, the infection rates of the corresponding HPV subtype decreased; however, HPV subtype infection not covered by the nine-valent vaccine should not be ignored.

Efficacy of AS04-Adjuvanted Vaccine Against Human Papillomavirus (HPV) Types 16 and 18 in Clearing Incident HPV Infections: Pooled Analysis of Data From the Costa Rica Vaccine Trial and the PATRICIA Study

Clinical trial data and real-world evidence suggest that the AS04-adjuvanted vaccine targeting human papillomavirus types 16 and 18 (AS04-HPV-16/18) vaccine provides nearly 90% protection against cervical intraepithelial neoplasia grade 3 or higher irrespective of type, among women vaccinated before sexual debut. This high efficacy is not fully explained by cross-protection. Although AS04-HPV-16/18 vaccination does not affect clearance of prevalent infections, it may accelerate clearance of newly acquired infections. We pooled data from 2 large-scale randomized controlled trials to evaluate efficacy of the AS04-HPV-16/18 vaccine against clearance of nontargeted incident infections. Results of our analysis do not suggest an effect in expediting clearance of incident infections.

Strong reduction in prevalence of HPV16/18 and closely related HPV types in sexually active adolescent women following the introduction of HPV vaccination in Argentina

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HPV16/18 decreased by >93% in vaccinated sexually active Argentine girls.

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Detected reduction of HPV31 and 45 would add to the success of immunization.

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No genotype replacement was observed.

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First HPV vaccination monitoring data reported from a Latin American country.

Efficacy of the AS04-Adjuvanted HPV16/18 Vaccine: Pooled Analysis of the Costa Rica Vaccine and PATRICIA Randomized Controlled Trials

BACKGROUND

The AS04-adjuvanted HPV16/18 (AS04-HPV16/18) vaccine provides excellent protection against targeted human papillomavirus (HPV) types and a variable degree of cross-protection against others, including types 6/11/31/33/45. High efficacy against any cervical intraepithelial neoplasia grade 3 or greater (CIN3+; >90%) suggests that lower levels of protection may exist for a wide range of oncogenic HPV types, which is difficult to quantify in individual trials. Pooling individual-level data from two randomized controlled trials, we aimed to evaluate AS04-HPV16/18 vaccine efficacy against incident HPV infections and cervical abnormalities .

METHODS

Data were available from the Costa Rica Vaccine Trial (NCT00128661) and Papilloma Trial Against Cancer in Young Adults trial (NCT00122681), two large-scale, double-blind randomized controlled trials of the AS04-HPV16/18 vaccine. Primary analyses focused on disease-free women with no detectable cervicovaginal HPV at baseline.

RESULTS

A total of 12 550 women were included in our primary analyses (HPV arm = 6271, control arm = 6279). Incidence of 6-month persistent oncogenic and nononcogenic infections, excluding known and accepted protected types 6/11/16/18/31/33/45 (focusing on 34/35/39/40/42/43/44/51/52/53/54/56/58/59/66/68/73/70/74), was statistically significantly lower in the HPV arm than in the control arm (efficacy = 9.9%, 95% confidence interval [CI] = 1.7% to 17.4%). Statistically significant efficacy (P < .05) was observed for individual oncogenic types 16/18/31/33/45/52 and nononcogenic types 6/11/53/74. Efficacy against cervical abnormalities (all types) increased with severity, ranging from 27.7% (95% CI = 21.7% to 33.3%) to 58.7% (95% CI = 34.1% to 74.7%) for cytologic outcomes (low-grade squamous intraepithelial neoplasia lesion or greater, and high-grade squamous intraepithelial neoplasia lesion or greater, respectively) and 66.0% (95% CI = 54.4% to 74.9%) to 87.8% (95% CI = 71.1% to 95.7%) for histologic outcomes (CIN2+ and CIN3+, respectively). Comparing Costa Rica Vaccine Trial and Papilloma Trial Against Cancer in Young Adults results, there was no evidence of heterogeneity, except for type 51 (efficacy = -28.6% and 20.7%, respectively; two-sided P = .03).

CONCLUSIONS

The AS04-HPV16/18 vaccine provides some additional cross-protection beyond established protected types, which partially explains the high efficacy against CIN3+.

B. Hanley S, Hara M, Adachi S, Ueda Y, Miyagi E, Ikeda S, Yagi A, Enomoto T. Epidemiologic Profile of Type-Specific Human Papillomavirus Infection after Initiation of HPV Vaccination

Organized human papillomavirus vaccination (OHPV) in Japan was introduced in 2010 for girls aged 12–16 years who were born in 1994 or later. The rate of OHPV coverage was 70–80%. However, after suspension of the government vaccination recommendation, the coverage dramatically decreased. We aim to investigate the change in prevalence of HPV infection after the initiation of HPV vaccination. We recruited females aged 20–21 years attending public cervical cancer screening from 2014 to 2017 fiscal years (April 2014 to March 2018). Residual Pap test specimens were collected for HPV testing. We compared the prevalence of HPV type-specific infection between women registered in 2014 (born in 1993–1994, including the pre-OHPV generation) and registered in 2015–2017 (born in 1994–1997, the OHPV generation). We collected 2379 specimens. The vaccination coverage figures were 30.7%, 86.6%, 88.4% and 93.7% (p < 0.01) from 2014 to 2017, respectively. The prevalence of HPV16/18 infection significantly decreased from 1.3% in 2014 to 0% in 2017 (p = 0.02). The three most prevalent types were HPV52, 16 and 56 in 2014, and HPV52, 58 and 56 in 2015–2017, respectively. HPV16 and 33 infection rates decreased. On the other hand, the HPV58 infection rate was obviously increased after OHPV from 0.3% to 2.1%. Our study demonstrates that the prevalence of HPV16/18 infection dramatically decreased and the profile of type-specific HPV infection was changed after OHPV.

Long-term follow-up of human papillomavirus type replacement among young pregnant Finnish females before and after a community-randomised HPV vaccination trial with moderate coverage

Large scale human papillomavirus (HPV) vaccination against the most oncogenic high-risk human papillomavirus (HPV) types 16/18 is rapidly reducing their incidence. However, attempts at assessing if this leads to an increase of nonvaccine targeted HPV types have been hampered by several limitations, such as the inability to differentiate secular trends. We performed a population-based serological survey of unvaccinated young women over 12 years. The women were under 23-years-old, residents from 33 communities which participated in a community-randomised trial (CRT) with approximately 50% vaccination coverage. Serum samples were retrieved pre-CRT and post-CRT implementation. Seropositivity to 17 HPV types was assessed. HPV seroprevalence ratios (PR) comparing the postvaccination to prevaccination era were estimated by trial arm. This was also assessed among the sexual risk-taking core group, where type replacement may occur more rapidly. In total, 8022 serum samples from the population-based Finnish Maternity Cohort were retrieved. HPV types 16/18 showed decreased seroprevalence among the unvaccinated in communities only after gender-neutral vaccination (PR_16/18A = 0.8, 95% CI 0.7-0.9). HPV6/11 and HPV73 were decreased after gender-neutral vaccination (PR_6/11A = 0.8, 95% CI 0.7-0.9, PR_73A = 0.7, 95% CI 0.6-0.9, respectively) and girls-only vaccination (PR_6/11B = 0.8, 95% CI 0.7-0.9, PR_73B = 0.9, 95% CI 0.8-1.0). HPV68 alone was increased but only after girls-only vaccination (PR_68B = 1.3, 95% CI 1.0-1.7, PR_core68B = 2.8, 95% CI 1.2-6.3). A large-scale, long-term follow-up found no type replacement in the communities with the strongest reduction of vaccine HPV types. Limited evidence for an increase in HPV68 was restricted to girls-only vaccinated communities and may have been due to secular trends (ClinicalTrials.gov number: NCT00534638).

Human Papillomavirus Genotype Replacement: Still Too Early to Tell?

Background

Although human papillomavirus (HPV) vaccines are highly efficacious in protecting against HPV infections and related diseases, vaccination may trigger replacement by nontargeted genotypes if these compete with the vaccine-targeted types. HPV genotype replacement has been deemed unlikely, based on the lack of systematic increases in the prevalence of nonvaccine-type (NVT) infection in the first decade after vaccination, and on the presence of cross-protection for some NVTs.

Methods

To investigate whether type replacement can be inferred from early postvaccination surveillance, we constructed a transmission model in which a vaccine type and an NVT compete through infection-induced cross-immunity. We simulated scenarios of different levels of cross-immunity and vaccine-induced cross-protection to the NVT. We validated whether commonly used measures correctly indicate type replacement in the long run.

Results

Type replacement is a trade-off between cross-immunity and cross-protection; cross-immunity leads to type replacement unless cross-protection is strong enough. With weak cross-protection, NVT prevalence may initially decrease before rebounding into type replacement, exhibiting a honeymoon period. Importantly, vaccine effectiveness for NVTs is inadequate for indicating type replacement.

Conclusions

Although postvaccination surveillance thus far is reassuring, it is still too early to preclude type replacement. Monitoring of NVTs remains pivotal in gauging population-level impacts of HPV vaccination.

Persisting Antibody Response 9 Years After Bivalent Human Papillomavirus (HPV) Vaccination in a Cohort of Dutch Women: Immune Response and the Relation to Genital HPV Infections

The bivalent human papillomavirus (HPV) vaccine is highly effective and induces robust serological responses. Using a Dutch prospective cohort initiated in 2009, including 744 vaccinated and 294 unvaccinated girls (1993–1994) who provide a vaginal self-swab sample, serum sample, and questionnaire yearly, we report a high, persisting antibody response up to 9 years after vaccination for vaccine types HPV-16 or HPV-18. Antibodies against nonvaccine HPV types 31, 33, 45, 52, and 58 were lower but still significantly higher than in unvaccinated individuals. This was also reflected in the seroprevalence. We compared participant characteristics and antibody levels between vaccinated women with and those without HPV infections 1 year before infection (204 incident and 64 persistent infections), but we observed no consistent difference in type-specific antibody levels. Having a high-risk HPV infection was associated with sexual risk behavior and smoking 1 year before infection. Although high antibody levels are necessary for protection, our study suggests that on the individual level other factors such as HPV exposure or antibody avidity could be important.

Bivalent Human Papillomavirus Vaccine Effectiveness in a Japanese Population: High Vaccine-Type-Specific Effectiveness and Evidence of Cross-Protection

Background

Proactive recommendations for human papillomavirus (HPV) vaccines in Japan have been suspended for 5 years because of safety concerns. While no scientific evidence exists to substantiate these concerns, one reason given for not reinstating recommendations is the lack of reliable vaccine effectiveness (VE) data in a Japanese population. This study reports the VE of the bivalent HPV vaccine in Japanese women aged 20–22 years.

Methods

During cervical screening between 2014 and 2016, women had Papanicolaou smears and HPV tests performed and provided data about their sexual history. Estimates of VE for vaccine-targeted HPV type 16 (HPV16) and 18 and cross-protection against other types were calculated.

Results

Overall, 2197 women were tested, and 1814 were included in the analysis. Of these, 1355 (74.6%) were vaccinated, and 1295 (95.5%) completed the 3-dose schedule. In women sexually naive at vaccination, the pooled VEs against HPV16 and 18 and for HPV31, 45, and 52 were 95.5% (P < .01) and 71.9% (P < .01), respectively. When adjusted for number of sex partners and birth year, pooled VEs were 93.9% (P = .01) and 67.7% (P = .01) for HPV16 and 18 and HPV31, 45, and 52, respectively.

Conclusions

The bivalent HPV vaccine is highly effective against HPV16 and 18. Furthermore, significant cross-protection against HPV31, 45, and 52 was demonstrated and sustained up to 6 years after vaccination. These findings should reassure politicians about the VE of bivalent HPV vaccine in a Japanese population.

Decline in vaccine-type human papillomavirus prevalence in young men from a Midwest metropolitan area of the United States over the six years after vaccine introduction

PURPOSE

The aim of this study was to determine changes in human papillomavirus (HPV) prevalence among young men from a Midwest metropolitan area over the six years after vaccine introduction, including HPV prevalence in men overall, in vaccinated men to examine vaccine impact and in unvaccinated men to examine herd protection. An exploratory aim was to examine associations between number of vaccine doses and HPV prevalence.

METHODS

Men aged 14-26 years reporting male-female and/or male-male sexual contact were recruited from a primary care clinic, sexually transmitted disease clinic, and community setting during two waves of data collection: 2013-2014 (N = 400) and 2016-2017 (N = 347). Participants completed a questionnaire and were tested for penile, scrotal and anal HPV. Changes in prevalence of any (≥1 type) and vaccine-type HPV (HPV6, 11, 16, and/or 18) were examined using propensity score weighted logistic regression. Associations between number of doses and HPV infection were determined using chi-square tests and logistic regression.

RESULTS

The proportion of men with a history of ≥1 HPV vaccine doses increased from 23% to 44% (p < 0.001) from waves 1 to 2. After propensity score weighting, infection with ≥1 vaccine-type HPV significantly decreased among all men (29% to 20%; 31% decrease; odds ratio [OR] = 0.62, 95% confidence interval [CI] = 0.44-0.88) and unvaccinated men (32% to 21%; 36% decrease; OR = 0.56, 95%CI = 0.34-0.86); there was a non-significant decrease (21%) among vaccinated men. Associations between number of doses and HPV prevalence were not statistically significant.

CONCLUSIONS

Prevalence of vaccine-type HPV decreased among all, vaccinated, and unvaccinated men six years after HPV vaccine recommendation, supporting vaccine impact and herd protection. Decreases in vaccine-type HPV in all men appear to be due to decreases in unvaccinated men, suggesting that the full impact of vaccination has yet to be realized. Continued monitoring and efforts to vaccinate men prior to sexual initiation are warranted.

Very Low Prevalence of Vaccine Human Papillomavirus Types Among 18- to 35-Year Old Australian Women 9 Years Following Implementation of Vaccination

Introduction

A quadrivalent human papillomavirus vaccination program targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of 14-26 year olds through 2009. We evaluated the program's impact on HPV prevalence among women aged 18-35 in 2015.

Methods

HPV prevalence among women aged 18-24 and 25-35 was compared with prevalence in these age groups in 2005-2007. For women aged 18-24, we also compared prevalence with that in a postvaccine study conducted in 2010-2012.

Results

For the 2015 sample, Vaccination Register-confirmed 3-dose coverage was 53.3% (65.0% and 40.3% aged 18-24 and 25-35, respectively). Prevalence of vaccine HPV types decreased from 22.7% (2005-2007) and 7.3% (2010-2012), to 1.5% (2015) (P trend < .001) among women aged 18-24, and from 11.8% (2005-2007) to 1.1% (2015) (P = .001) among those aged 25-35.

Conclusions

This study, reporting the longest surveillance follow-up to date, shows prevalence of vaccine-targeted HPV types has continued to decline among young women. A substantial fall also occurred in women aged 25-35, despite lower coverage. Strong herd protection and effectiveness of less than 3 vaccine doses likely contributed to these reductions.

High-resolution HLA allele and haplotype frequencies in majority and minority populations of Costa Rica and Nicaragua: Differential admixture proportions in neighboring countries

The HLA system shows the most extensive polymorphism in the human genome. Allelic and haplotypic frequencies of HLA genes vary dramatically across human populations. Due to a complex history of migration, populations in Latin America show a broad variety of admixture proportions, usually varying not only between countries, but also within countries. Knowledge of HLA allele and haplotype frequencies is essential for medical fields such as transplantation, but also serves as a means to assess genetic diversity and ancestry in human populations. Here, we have determined high-resolution HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies in a sample of 713 healthy subjects from three Mestizo populations, one population of African descent, and Amerindians of five different groups from Costa Rica and Nicaragua and compared their profiles to a large set of indigenous populations from Iberia, Sub-Saharan Africa, and the Americas. Our results show a great degree of allelic and haplotypic diversity within and across these populations, with most extended haplotypes being private. Mestizo populations show alleles and haplotypes of putative European, Amerindian, and Sub-Saharan African origin, albeit with differential proportions. Despite some degree of gene flow, Amerindians and Afro-descendants show great similarity to other Amerindian and West African populations, respectively. This is the first comprehensive study reporting high-resolution HLA diversity in Central America, and its results will shed light into the genetic history of this region while also supporting the development of medical programs for organ and stem cell transplantation.

HPV-related oropharyngeal cancer: a review on burden of the disease and opportunities for prevention and early detection

The incidence of oropharyngeal cancer (OPC) related to infection with human papillomavirus (HPV) is rising, making it now the most common HPV-related malignancy in the United States. These tumors present differently than traditional mucosal head and neck cancers, and those affected often lack classic risk factors such as tobacco and alcohol use. Currently, there are no approved approaches for prevention and early detection of disease, thus leading many patients to present with advanced cancers requiring intense surgical or nonsurgical therapies resulting in significant side effects and cost to the health-care system. In this review, we outline the evolving epidemiology of HPV-related OPC. We also summarize the available evidence corresponding to HPV-related OPC prevention, including efficacy and safety of the HPV vaccine in preventing oral HPV infections. Finally, we describe emerging techniques for identifying and screening those who may be at high risk for developing these tumors.

Eradication of human papillomavirus and elimination of HPV-related diseases - scientific basis for global public health policies

INTRODUCTION

Infections with oncogenic human papillomaviruses (HPV) globally cause about 9% of cancers in females and 1% of cancers in males. HPV disease burden can be effectively controlled by prophylactic HPV-vaccination provided it has high impact.

AREAS COVERED

A unique series of biobank-based and health registry-based studies that exploit randomized intervention cohorts has provided data on population-level safety of HPV vaccination, duration of vaccine-induced protection and impact of gender-neutral HPV vaccination, providing a scientific basis for policies to eradicate oncogenic HPV types and associated diseases worldwide.

EXPERT COMMENTARY

The ultimate goal of HPV vaccination is the eradication of high-risk (hr) HPVs. Seventy-five percent coverage gender-neutral vaccination of early adolescents will rapidly eradicate also HPV16 from the general population.

Distinct geographic clustering of oncogenic human papillomaviruses multiple infections in cervical cancers: Results from a worldwide cross-sectional study

Coinfections by multiple Human Papillomaviruses (HPVs) are observed in approximately 6-8% of invasive cervical cancer (ICC) cases worldwide. But neither the presence of persistent HPVs coinfections nor their etiological role in the development of ICC is well understood. Cervical HPVs coinfections have been observed randomly, mostly in women with preneoplastic lesions, and only few studies have globally analyzed ICC cases. Here we explored the HPVs multiple infection patterns in a large worldwide sample of cross-sectional ICC cases. Paraffin-embedded ICC biopsy samples were tested using stringent HPV genotyping. Logistic regression models were used to identify the most likely pairwise HPV types in multiple infections. Multivariate analysis was applied to detect significant HPV coinfection patterns beyond pairwise HPVs comparison. Among 8780 HPV DNA-positive ICC cases worldwide, 6.7% (N = 587) contained multiple HPVs. Pairwise analysis revealed that HPV16|74, HPV31|33, HPV31|44, HPV33|44 and HPV45|70 pairs were significantly more frequently found together in multiple infections compared to any other HPV type combination, which supports the occasional role of Alpha-10 LR-HPVs in cervical cancers. In contrast, HPV16|31, HPV16|45, HPV16|51 and HPV18|HPV45 pairs were significantly less frequently found together than with any other HPV pair combination. Multivariate analysis sustained the results and revealed for the first time a distinct coinfection pattern in African ICCs stemming from the clustering of oncogenic HPV51/35/18/52 coinfections in African women. We suggest that the differential geographic HPVs coinfections clustering observed might be compatible with a specific modulation of the natural history/oncogenic potential of particular HPVs multiple infections and warrant monitoring for post-vaccinated.

Age-Structured Population Modeling of HPV-related Cervical Cancer in Texas and US

Human papillomavirus (HPV)-related cervical cancer is a major public health threat to women, with >10,000 new cases diagnosed annually in the United States between 2008 and 2012. Since HPV vaccines can protect against ~80% of HPV-associated cervical cancers, the economic and epidemiological impacts of HPV vaccination have been extensively investigated, particularly at the national level. However, vaccination policies are state-specific, and state-level models are required for state-specific policy decisions. This study adapted an age-structured population model to describe the dynamics of HPV-related cervical cancer in Texas, with model parameters calibrated for Texas. The Year 2000 parameter set was the start point, and the model's predictions from 2001-2010 were well matched with the real incidence numbers in 23 age groups, suggesting the validity of the model. Application of the model to the Year 2010 parameter set predicted that, over the next 10 decades, incidence would decrease rapidly within the first decade and more slowly thereafter. Sensitivity analysis determined the impact of selected parameters (e.g., vaccine coverage rate) on future disease incidence. When compared with the US parameter sets, the Texas population was more sensitive to changes in HPV transmission and vaccination (e.g., ~8% difference in the predicted disease decline).

Proposal for cervical cancer screening in the era of HPV vaccination

Eradication of cervical cancer involves the expansion of human papillomavirus (HPV) vaccine coverage and the development of efficient screening guidelines that take vaccination into account. In Korea, the HPV National Immunization Program was launched in 2016 and is expected to shift the prevalence of HPV genotypes in the country, among other effects. The experiences of another countries that implement national immunization programs should be applied to Korea. If HPV vaccines spread nationwide with broader coverage, after a few decades, cervical intraepithelial lesions or invasive cancer should become a rare disease, leading to a predictable decrease in the positive predictive value of cervical screening cytology. HPV testing is the primary screening tool for cervical cancer and has replaced traditional cytology-based guidelines. The current screening strategy in Korea does not differentiate women who have received complete vaccination from those who are unvaccinated. However, in the post-vaccination era, newly revised policies will be needed. We also discuss on how to increase the vaccination rate in adolescence.

Prevalence and distribution of human papillomavirus genotypes in Chinese women between 1991 and 2016: A systematic review

BACKGROUND

Human papillomavirus (HPV) associated cervical cancer is one of the most common cancers and ranked as the eighth most common killer for Chinese women. A dozen of HPV vaccines are being developed in China without a solid China-specific distribution of carcinogenic HPV types, thus, we performed this systematic review to explore the China-specific spectrum of high-risk types causing cancer.

METHODS

Studies on HPV infection among Chinese women were searched. All retrieved articles were screened and reviewed by a standardized algorithm. Distribution of carcinogenic HPV types and age-specific prevalence were analyzed using random-effects model.

RESULTS

A total of 303 articles were included in the final analysis. The top 10 common HPV types detected in ICC patients, in descending order of frequency, were HPV 16 (62.5%), 18 (12.4%), 58 (8.6%), 52 (5.7%), 33 (4.6%), 31 (3.5%), 55 (2.4%), 68 (2.4%), 53 (2.2%) and 45 (2.0%) respectively. Similar spectrum was found in women with precancer. The prevalence of HPV infection peaked between 20 and 24 years with a rate of 24.3%, thereafter declined substantially and stabilized at middle-ages. Compared to women living in the developed provinces, the second peak was observed among women aged 45-55 years in less developed regions.

CONCLUSION

In general, the spectrum of HPV types in women with precancer/cancer and the pattern of age-specific prevalence were consistent with that of elsewhere worldwide. However, some distinguished characteristics could also be concluded, and these imprinting should be considered and integrated when developing vaccines and strategy for disease control in China.

Projected future impact of HPV vaccination and primary HPV screening on cervical cancer rates from 2017-2035: Example from Australia

Background

Many countries are transitioning from cytology-based to longer-interval HPV screening. Trials comparing HPV-based screening to cytology report an increase in CIN2/3 detection at the first screen, and longer-term reductions in CIN3+; however, population level year-to-year transitional impacts are poorly understood. We undertook a comprehensive evaluation of switching to longer-interval primary HPV screening in the context of HPV vaccination. We used Australia as an example setting, since Australia will make this transition in December 2017.

Methods

Using a model of HPV vaccination, transmission, natural history and cervical screening, Policy1-Cervix, we simulated the planned transition from recommending cytology every two years for sexually-active women aged 18–20 to 69, to recommending HPV screening every five years for women aged 25–74 years. We estimated rates of CIN2/3, cervical cancer incidence, and mortality for each year from 2005 to 2035, considering ranges for HPV test accuracy and screening compliance in the context of HPV vaccination (current coverage ~82% in females; ~76% in males).

Findings

Transient increases are predicted to occur in rates of CIN2/3 detection and invasive cervical cancer in the first two to three years following the screening transition (of 16–24% and 11–14% in respectively, compared to 2017 rates). However, by 2035, CIN2/3 and invasive cervical cancer rates are predicted to fall by 40–44% and 42–51%, respectively, compared to 2017 rates. Cervical cancer mortality rates are predicted to remain unchanged until ~2020, then decline by 34–45% by 2035. Over the period 2018–2035, switching to primary HPV screening in Australia is expected to avert 2,006 cases of invasive cervical cancer and save 587 lives.

Conclusions

Transient increases in detected CIN2/3 and invasive cancer, which may be detectable at the population level, are predicted following a change to primary HPV screening. This is due to improved test sensitivity bringing forward diagnoses, resulting in longer term reductions in both cervical cancer incidence and mortality. Fluctuations in health outcomes due to the transition to a longer screening interval are predicted to occur for 10–15 years, but cervical cancer rates will be significantly reduced thereafter due to the impact of HPV vaccination and HPV screening. In order to maintain confidence in primary HPV screening through the transitional phase, it is important to widely communicate that an initial increase in CIN2/3 and perhaps even invasive cervical cancer is expected after a national transition to primary HPV screening, that this phenomenon is due to increased prevalent disease detection, and that this effect represents a marker of screening success.

Differences between vaccinated and unvaccinated women explain increase in non-vaccine-type human papillomavirus in unvaccinated women after vaccine introduction

The aim of this study was to determine whether an observed increase in non-vaccine-type human papillomavirus (HPV) in unvaccinated women during the first eight years after vaccine introduction may be explained by differences in demographics or sexual behaviors, instead of type replacement. We analyzed data from three cross-sectional surveillance studies of 13-26 year-old women (total N = 1180). For women recruited from a health department clinic, older age (OR = 1.4, 95% CI: 1.2-1.6) and consistent condom use with main partner in the past 3 months (OR = 11.6, 95% CI: 3.4-40) were associated with being unvaccinated. For women recruited from a teen health center African American race (OR = 0.2, 95% CI: 0.07-0.7) and having Medicaid health insurance (OR = 0.3, 95% CI: 0.1-0.7) were inversely associated with being unvaccinated. The observed increase in non-vaccine-type HPV prevalence in unvaccinated women may be explained by differences between unvaccinated and vaccinated women.

Cervical cancer screening in the era of HPV vaccination: A review of shifting paradigms in cytopathology

Significant changes in cervical cancer screening practice, guidelines, and prevention of cervical cancer have taken place in recent years including the raising of initial cervical cancer screening age, changes in frequency of cytology screening, and the adoption of high risk HPV and cytology co-testing for some patients; the introduction of the bivalent, quadrivalent, and 9-valent HPV vaccines; and the recent approval of high risk HPV testing as primary screening with the use of cytology as triage in positive cases. This review discusses the significance of primary HPV screening, the impact of HPV vaccination in the prevalence of cervical cancer and its precursors, the interplay between high risk HPV testing and vaccination, and the implications for clinical and cytological management. Future strategies for cervical screening in the post-vaccination era are also discussed.