Reduction in HPV 16/18 prevalence among young women following HPV vaccine introduction in a highly vaccinated district, Japan, 2008-2017

Genital and Oral HPV Geno-Prevalence Measured through Urine and Saliva Samples in Young Adults in Italy

BACKGROUND

The aims of the study were to determine, in the urine and oral samples of young adults, the genotype-specific prevalence of Human Papilloma Virus (HPV) infection, the HPV DNA type-specific prevalence in unvaccinated and vaccinated individuals, and the determinants of HPV infection.

METHODS

Selected participants were asked to fill in a self-administered questionnaire and to self-collect urine and saliva samples.

RESULTS

Among the 1002 participants, 81 (8.1%) resulted positive for HPV DNA. The most common low-risk genotype was HPV 42 (2.2%), followed by HPV 43 (0.8%), and 40 (0.5%). The HPV 51 was the most common high-risk genotype (1.5%) followed by HPV 66 (1%) and HPV 68 (1%), and no participants were infected with HPV genotypes 18, 33, 45. Females, those who have had one or more occasional sexual partner, those who never/rarely/sometimes used condoms during their sexual activity, those with a previous diagnosis of sexually transmitted infection, and those who were not vaccinated were more likely to be tested positive for HPV infection.

CONCLUSIONS

The low prevalence of genital HPV infections has provided evidence of the effectiveness of HPV vaccination both in vaccinated and not yet vaccinated subjects through herd immunity and indicated its decisive role in the changing epidemiology of circulating HPV genotypes in the population.

Effectiveness of prophylactic HPV vaccines against cervical abnormalities and HPV infection in Japan: The J-HERS 2021 multicenter study

This study investigated the efficacy of the prophylactic human papillomavirus (HPV) vaccine, which was initiated between 2009 and 2013 in Japan. The study involved 1529 eligible women aged 16-39 years who visited 11 outpatient clinics in Japan for various reasons. These patients underwent HPV genotype analysis and a Pap test of cervical cell samples. A total of 299 women (19.6%) had received the prophylactic HPV vaccine (bivalent:quadrivalent vaccine ratio = 2:1). Of the 5062 participants in the Japanese Human Papillomavirus Disease Education and Research Survey (J-HERS 2011), which was conducted in the pre-vaccination era, 3236 eligible participants were included as controls. In this study (J-HERS 2021), the highest rate of HPV vaccination (53%) was observed in patients aged 22-27 years. Vaccinated individuals exhibited a 49% rate of protection against low-grade intraepithelial lesions (LSILs) and atypical squamous cells, not excluding high-grade squamous intraepithelial lesions (ASCH) or worse (LSIL/ASCH+), and a 100% rate of protection against high-grade squamous intraepithelial lesions (HSILs) or worse (HSIL+). Significant reductions in HPV16 (95%) and HPV18 (100%) infections were noted, but no differences were observed in HPV6 and HPV11 infections. The prevalences of HPV51 and HPV59 increased with vaccination, although these changes were not confirmed in the comparative study with J-HERS 2011. Comparing the prevaccination (J-HERS 2011) and postvaccination (J-HERS 2021) periods, 43%, 51%, 88%, and 62% reductions in HPV16, HPV18, HPV16/18, and HPV31/58 infection rates were observed, respectively. Similarly, 62% and 71% reductions in LSIL/ASCH+ and HSIL+ rates were noted, respectively. There were 88% and 87% reductions in LSIL/ASCH+ and HSIL+ rates in 16-21- and 28-33-year-old patients, respectively. Bivalent or quadrivalent vaccines provided 100% protection against high-grade squamous cell lesions (suggestive of CIN2 or CIN3) in young women aged <39 years at 9-12 years after initiation of Japan's first nationwide HPV vaccination program. Cross-protection against HPV31 and HPV58 is likely to occur, although some HPV-type replacements are inconsistent across vaccination regimens. This demonstrates the effectiveness of the HPV vaccine. However, continuous monitoring of cervical cancer and precancer is necessary in younger generations (born 1997-2007), who were rarely vaccinated due to the prolonged suspension of the vaccine recommendations in Japan.

Distribution of cervical intraepithelial neoplasia is closely associated with HPV status and uterine position

Although cervical intraepithelial neoplasia (CIN) lesions are considered to be not randomly distributed across the cervix, but predominantly in the anterior wall, the clinicopathological etiology remains unknown. Herein, we aimed to elucidate the relationship between quantitatively measured area of CIN2/3 and cervical cancer associated factors by retrospective cohort study. We analyzed 235 consecutive therapeutic conization specimens dissected as a single intact section to determine CIN2/3 area and its correlation with both clinical risk factors including human papillomavirus (HPV) status (single or multiple infection) and uterine position defined by transvaginal ultrasound. Cervical wall was classified into three groups: anterior: (11, 12, 1, and 2 o'clock), posterior (5, 6, 7, and 8 o'clock) and lateral (3, 4, 9, and 10 o'clock). Multiple regression revealed that younger age and HPV16 status were significantly correlated with CIN2/3 area (p = 0.0224 and p = 0.0075, respectively). The Jonckheere-Terpstra test showed a significant trend: CIN2/3 area was highest in the single HPV16 group, followed by the multiple HPV16 group and the non-HPV16 group (p < 0.0001). CIN2/3 area in the anterior wall was statistically significantly larger than the posterior and lateral wall (p = 0.0059 and p = 0.0107, respectively). CIN2/3 area in the anterior wall was significantly greater with anteversion-anteflexion than retroversion-retroflexion (p = 0.0485), whereas CIN2/3 area in the posterior wall was significantly larger with retroversion-retroflexion than anteversion-anteflexion (p = 0.0394). In conclusion, the topographical distribution of CIN2/3 area is closely associated with patient age, high-risk HPV status, especially single HPV16 infection and uterine position.

Prevalence of Human Papillomavirus Types 16/18 and Effect of Vaccination among Japanese Female General Citizens in the Vaccine Crisis Era

The Japanese government withdrew its recommendation for human papillomavirus (HPV) vaccination in June 2013 and resumed it in April 2022. This period is known as the vaccine crisis in Japan. This study aimed to elucidate the prevalence and genotype distribution of HPV among Japanese female citizens, and the effect of vaccination against HPV-16/18 in the era of the vaccine crisis. We recruited Japanese female citizens and asked them to provide self-collected samples from the vaginal wall using cotton swabs for HPV genotyping. Furthermore, we collected the participants' characteristics, including lifestyle and experience of vaccination against HPV, to determine the significant association with HPV infection. HPV-16/18 positivity was found in 5.6% (115/2044) of participants. The highest vaccination rate was observed in the age group of 20-24 years (60.6%), whereas the lowest HPV-16/18 positivity was observed in the age group of 45-49 years (2.8%), followed by the age group of 20-24 years (4.0%). Experience with HPV vaccination significantly reduced the risk of HPV-16/18 infection (adjusted odds ratio, 0.047; 95% confidence interval, 0.011-0.196). Vaccinated women were much less likely to be infected by HPV-16/18, regardless of the HPV vaccine type or the vaccination dose.

Changes in genital Human Papillomavirus (HPV) prevalence among urban females a decade after the Malaysian HPV vaccination program

To increase the coverage of HPV vaccination, Malaysia implemented a national school-based vaccination program for all 13-year-old girls in 2010. Two years later, a clinic-based catch-up program was started for 16 to 21-year-old girls. We assessed the prevalence of a range of HPV genotypes, among a sample of urban women within the age groups of 18-24 and 35-45 years in 2019-2020, a decade into the national vaccination program. The HPV prevalence was then compared to that reported in an unvaccinated population in 2013-2015. We sampled a total of 1134 participants, comprising of 277 women aged 18-24 years and 857 women aged 35-45 years, from several urban clinics in the state of Selangor. Participants provided a self-acquired vaginal sample for HPV genotyping. Comprehensive sociodemographic and vaccination history were collected. The HPV vaccination coverage among women in the younger age group increased from 9.3% in 2013-2015 to 75.5% in 2019-2020. The prevalence of vaccine-targeted HPV16/18 decreased 91% (CI: 14.5%-99.0%) among the younger women, from 4.0% in 2013-2015 to 0.4% in 2019-2020. There was also an 87% (CI: 27.5%-97.5%) reduction in HPV6/11/16/18. There was no difference in the prevalence of non-vaccine targeted HPV genotypes among younger women. The HPV prevalence among older women, for both vaccine targeted and non-vaccine targeted genotypes in 2019-2020, did not differ from 2013-2015. The observed decline in prevalence of vaccine-targeted HPV genotype among younger women a decade after the national HPV vaccination program is an early indication of its effectiveness in reducing the burden of cervical cancer.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Which is the best management for women with normal cervical cytologic findings despite positivity for non-16/18 high risk human papillomaviruses?

Women who test positive for the human papillomavirus (HPV) but have normal cytology constitute the predominant subgroup of patients in the screening population in the post-vaccination era. The distribution of HPV genotypes changed dramatically, which was attributable to an increase in HPV vaccination coverage. These changes have created uncertainty about how to properly manage women with normal cytology, non-HPV16/18 infections, or persistent infections. Current recommendations include retesting and continued surveillance in the absence of HPV16/18 infection. However, these are not always applicable. The ability to implement genotyping or incorporate HPV16/18 with some additional high-risk HPV (HR-HPV) types for triage and management with the aim of identifying type-specific risks in this population could be acceptable. When the next set of guidelines is updated, generating potential triage strategies for detecting high-grade cervical lesions, such as the p16/Ki67 cytology assay and other alternatives that incorporate genotyping with newer tests, should be considered. Current clinical management is shifting to risk-based strategies; however, no specific risk threshold has been established in this population. Importantly, innovative triage testing should be evaluated in combination with primary screening and management. Furthermore, there is an untapped opportunity to coordinate HPV genotyping in combination with colposcopic characteristics to modify risk in this group. Hence, providing a more personalized schedule through the efficient application of risk stratification and improving the detection of pre-cancer and cancer is an option worth exploring.

Effectiveness of HPV vaccine against cervical precancer in Japan: multivariate analyses adjusted for sexual activity

Japanese girls aged 12–16 years are offered free human papillomavirus (HPV) vaccination and cervical cancer screening is conducted with cytology and not HPV testing from the age of 20 years. So far, no study has analyzed the effect of HPV vaccination against cervical precancers considering HPV infection status and sexual activity. We aimed to analyze the vaccine effectiveness (VE) against HPV infection and cytological abnormalities, adjusted for sexual activity. This study comprised women aged 20–26 years who underwent cervical screening in Niigata. We obtained HPV vaccination status from municipal records and a questionnaire along with information concerning sexual activity. Of 5194 women registered for this study, final analyses included 3167 women in the vaccinated group (2821 vaccinated women prior to sexual debut) and 1386 women in the unvaccinated group. HPV 16/18 (0.2% vs 3.5%), 31/45/52 (3.4% vs 6.6%), and 31/33/45/52/58 (5.0% vs 9.3%) positive rates were significantly lower in the vaccinated group (P < 0.001). No women vaccinated before sexual debut had HPV 16/18‐related cytological abnormalities. VE for HPV 16/18 infection and high‐grade cytological abnormalities in women vaccinated prior to sexual debut were 95.8% (95% CI 81.9–99.0%; P < 0.001) and 78.3% (95% CI 11.3–94.7%; P = 0.033), respectively, in multivariate analyses adjusted for age and number of sexual partners. However, analyses of all vaccinated women did not show significant effectiveness against cytological abnormalities. Our results showed the effectiveness of HPV vaccine against high‐grade cervical cytological abnormalities and the importance of the vaccination before sexual debut.

A community-based approach to cervical cancer prevention in western Kenya: An AMPATH feasibility project

Objectives

Centralized programs have been ineffective in reducing the burden of cervical cancer among Kenyan women. A community-based pilot study was initiated to screen Kenyan women for cervical cancer and to vaccinate their children against human papillomavirus (HPV).

Methods

Women were educated about cervical cancer prevention at community meetings. Women then provided self-collected vaginal swabs for oncogenic HPV testing using the Roche Cobas Assay. All women were then referred to the local clinic for Visual Inspection with Acetic Acid (VIA). Women were offered the quadrivalent HPV vaccine for their children if and when it became available for the study.

Results

Women in western Kenya were invited to participate in community meetings. A total of 200 women were enrolled: 151 (75.5%) were HIV-uninfected and 49 (24.5%) were HIV-infected; the median age for all women was 42 years. High-risk (HR)-HPV types were detected in 49 of swabs from all 200 participants (24.5%) including 20.5% of HIV-uninfected women and 36.7% of HIV-infected women (P = .022). VIA was performed on 198 women: 192 had normal examinations and six had abnormal examinations. Five cervical biopsies revealed two cases of CIN 2 and one CIN 3. Although all mothers were willing to have their children (N = 432) vaccinated, the HPV vaccine could not be delivered to Kenya during the study period.

Conclusions

Kenyan women were willing to attend community meetings to learn about prevention of cervical cancer, to provide self-collected vaginal swabs for HPV testing, to travel to the Webuye Clinic for VIA following the collection of swabs, and to have their children vaccinated against HPV. HR-HPV was prevalent, especially in HIV-infected women. As a result of this pilot study, this community-based strategy to prevent cervical cancer will be continued in western Kenya.

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.

Postvaccination prevalence of vaccine-Human Papillomavirus (vHPV) genotypes among the target population: A systematic review and meta-analysis

Human Papillomavirus (HPV) vaccines are safe and are highly effective in reducing the prevalence of HPV infections and subsequent HPV associated diseases in the target population. A systematic review and meta-analysis was carried out searching electronic databases for articles published between January 2007 and September 2020 reporting the prevalence estimates of vaccine HPV (vHPV) types in women who had received one or more doses of quadrivalent or bivalent vaccines. This systematic review was based on standard systematic review guidelines and the meta-analysis was performed by pooling the HPV vaccine type prevalence data with 95% confidence interval (CI) among 16,929 young women who had received the prophylactic HPV vaccines before the age of 27 years. The overall pooled prevalence of vHPV types was.0.04 (95% CI: 0.02, 0.05). The meta-analysis concludes that prophylactic HPV vaccination before the age of 27 years results in a decline of vHPV types in young women.

Human papillomavirus vaccine to prevent cervical intraepithelial neoplasia in Japan: A nationwide case-control study

Cervical cancer remains among the most common cancers in women worldwide and can be prevented by vaccination. The Ministry of Health, Labour and Welfare of Japan suspended active recommendation of regular human papillomavirus (HPV) vaccines in 2013 because of various symptoms including chronic pain and motor impairment. This nationwide case-control study from April 2013 to March 2017 targeted women aged 20-24 years old at cervical screening. We compared HPV vaccination exposure between those with abnormal and normal cytology. Abnormal cytology was classified based on the results of histological test and we calculated the odds ratio (OR) and 95% confidence interval (CI) of the above endpoints and vaccination exposure using the conditional logistic regression model and estimated vaccine effectiveness using the formula (1 - OR) × 100. A total of 2483 cases and 12 296 controls (one-to-five matching) were eligible in 31 municipalities in Japan. The distribution of histological abnormalities among cases was 797 CIN1 (including dysplasia) (32.1%), 165 CIN2 (6.7%), 44 CIN3 (1.8%), and eight squamous cell carcinoma (SCC) (0.3%). The OR of HPV vaccination compared with no vaccination for abnormal cytology, CIN1+, CIN2+, and CIN3+ versus controls was 0.42 (95% CI, 0.34-0.50), 0.42 (95% CI, 0.31-0.58), 0.25 (95% CI, 0.12-0.54), and 0.19 (95% CI, 0.03-1.15), respectively, equating to a vaccine effectiveness of 58.5%, 57.9%, 74.8%, and 80.9%, respectively. Eight patients had SCC, none was vaccinated. This nationwide case-control study in Japan demonstrated a substantial risk reduction in abnormal cytology and CIN among women who did versus those who did not receive HPV vaccination.