Cross-protective efficacy of HPV-16/18 AS04-adjuvanted vaccine against cervical infection and precancer caused by non-vaccine oncogenic HPV types: 4-year end-of-study analysis of the randomised, double-blind PATRICIA trial

Lack of detectable HPV18 antibodies in 14% of quadrivalent vaccinees in a longitudinal cohort study

Although HPV vaccines are highly efficacious, a notable proportion of quadrivalent vaccinees are HPV18 seronegative post-vaccination. We have investigated this findings' validity by comparing vaccine-induced antibody responses using two different immunoassays. 6558 16-17-year-old females participated in the FUTURE II (NCT00092534) and PATRICIA (NCT00122681) trials in 2002-2004. Both the quadrivalent and bivalent vaccine recipients (QVR and BVR) received three doses. Twelve-year follow-up for 648 vaccinees was conducted by the Finnish Maternity Cohort. The presence of neutralising and binding HPV antibodies was analysed via HPV pseudovirion-based neutralisation and pseudovirion-binding assays. Four percent and 14.3% of the QVRs were seronegative for neutralising and binding antibodies to HPV16 and HPV18, respectively. No BVRs were HPV16/18 seronegative post-vaccination. The antibody titres were strongly correlated between the assays, Pearson's correlation coefficient, r[HPV16] = 0.92 and 0.85, and r[HPV18] = 0.91 and 0.86 among the QVRs and BVRs respectively. Fourteen percent of QVRs lacked detectable HPV18 antibodies in long-term follow-up.

Investigating under-reported human papillomavirus genotypes in Grenadian women through self-sampling for cervical cancer screening

Objective

To compare the adequacy, agreement, and acceptability of Papanicolaou testing (cytology) for cervical cancer screening using self-collected samples compared to physician-collected samples in Grenada in the Caribbean. Furthermore, the study identifies the human papillomavirus (HPV) genotypes present among asymptomatic women testing positive for HPV, the etiologic cause of cervical cancer.

Methods

Participants were divided into two groups and two cervical samples were collected from the women in each group: a self-collected sample and a physician-collected sample. Cervical specimens were tested for cytology and HPV. HPV genotyping was performed on positive specimens.

Results

Self-collected samples were adequate and in agreement with physician-collected samples, showing no difference between the two sampling methods. Oncogenic high-risk HPV genotypes were identified in cervical samples which were positive for atypical squamous cells and low-grade squamous intraepithelial lesions. The high-risk HPV genotypes found, notably HPV 45 and 53, differed from those most commonly reported. Although the commonly reported high-risk genotypes HPV 16 and 18 were found, so were 31, 33, 35, 52, 66, 68, and 82.

Conclusions

Using self-collection facilitated the discovery of unexpected HPV genotypes among asymptomatic women in Grenada. These findings add new information to the literature regarding cervical cancer and neoplasia screening and HPV genotypes in the Caribbean. This genotype information may impact surveillance of women with low-grade lesions, HPV vaccine selection, and possibly further vaccine research. Research regarding HPV in Caribbean pathology samples of cervical neoplasia and cancer is needed.

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Differential long-term bivalent HPV vaccine cross-protection by variants in the Costa Rica HPV vaccine trial

The AS04-adjuvanted human papillomavirus (HPV)16/18 vaccine, an L1-based vaccine, provides strong vaccine efficacy (VE) against vaccine-targeted type infections, and partial cross-protection to phylogenetically-related types, which may be affected by variant-level heterogeneity. We compared VE against incident HPV31, 33, 35, and 45 detections between lineages and SNPs in the L1 region among 2846 HPV-vaccinated and 5465 HPV-unvaccinated women through 11-years of follow-up in the Costa Rica HPV Vaccine Trial. VE was lower against HPV31-lineage-B (VE=60.7%;95%CI = 23.4%,82.8%) compared to HPV31-lineage-A (VE=94.3%;95%CI = 83.7%,100.0%) (VE-ratio = 0.64;95%CI = 0.25,0.90). Differential VE was observed at several lineage-associated HPV31-L1-SNPs, including a nonsynonymous substitution at position 6372 on the FG-loop, an important neutralization domain. For HPV35, the only SNP-level difference was at position 5939 on the DE-loop, with significant VE against nucleotide-G (VE=65.0%;95%CI = 28.0,87.8) but not for more the common nucleotide-A (VE=7.4%;95%CI = -34.1,36.7). Because of the known heterogeneity in precancer/cancer risk across cross-protected HPV genotype variants by race and region, our results of differential variant-level AS04-adjuvanted HPV16/18 vaccine efficacy has global health implications.

Evaluation of an E6/E7 PCR-capillary electrophoresis fragment analysis in the genotyping of human papillomavirus in archival FFPE samples of oropharyngeal cancer

Accumulating evidence has demonstrated that high-risk human papillomaviruses (HR-HPVs) are involved in the etiology of a subset of oropharyngeal squamous cell carcinoma (OPSCC). In this regard, the International Agency for Research on Cancer (IARC) has recommended direct molecular HPV testing. So far, there is no agreement on the most appropriate method for HPV detection on OPSCC formalin-fixed paraffin-embedded (FFPE) materials. In this study, we aimed to evaluate the performance of the high-sensitive SureX HPV assay in OPSCC FFPE tissues compared with LiPA-25 and p16ink4a immunostaining. A retrospective series of FFPE primary OPSCC cases were diagnosed between 2008 and 2019 and provided by the Henan Cancer Hospital, China. The level of agreement of two assays was determined using Cohen's Kappa (κ) statistics. A total of 230 FFPE OPSCC samples from tumor resections (n = 160) and diagnostic biopsies (n = 70) were detected. Sixty-six (28.7%) and 70 (30.4%) samples were identified as HPV-DNA-positive by LiPA-25 and SureX, respectively, of which HPV16 was largely the most common type (95.5% vs 94.3%). We found a perfect concordance between LiPA-25 and SureX for HPV-DNA status (κ = 0.906, 95% CI: 0.875-0.937) and for HPV16 (κ = 0.925, 95% CI: 0.897-0.953). In addition, SureX and p16ink4a immunostaining had a perfect concordance (κ = 0.917, 95% CI: 0.888-0.946). Moreover, the HPV-driven fraction, based on double positivity for HPV-DNA and p16ink4a, was similar between SureX (63 of 230, 27.4%) and LiPA-25 (60 of 230, 26.1%). Similar results were found in samples from resections and biopsies. SureX and LiPA-25 are comparable. SureX could be used for routine HPV-DNA detection and genotyping on archival OPSCC FFPE tissues.

Comparative Effects of Bivalent, Quadrivalent, and Nonavalent Human Papillomavirus Vaccines in The Prevention of Genotype-Specific Infection: A Systematic Review and Network Meta-Analysis

BACKGROUND

Human papillomavirus (HPV) infection is a major global disease burden and the main cause of cervical cancer. Certain HPV genotypes, with are the most common etiologic pathogens and cause a significant disease burden, are being targeted for vaccine development. However, few studies have focused on the comparative effectiveness of the bivalent HPV (2v-HPV), quadrivalent HPV (4v-HPV), and nonavalent HPV (9v-HPV) vaccines against HPV strain-specific infection. This study investigated the comparative effects of these vaccines against genotype-specific infection.

MATERIALS AND METHODS

We conducted a pairwise and network meta-analysis of published randomized clinical trials of HPV vaccines according to sex and HPV infection status for nine HPV genotypes (HPV 6/11/16/18/31/33/45/52/58).

RESULTS

Overall, 10 randomized controlled trials (12 articles) were included in this study. In the network meta-analysis, no statistically significant differences were observed in the prevention of carcinogenic HPV strains (16/18/31/33/45/52/58) between the 2v-HPV and 4v-HPV vaccines in female HPV infection-naïve populations. However, the 9v-HPV vaccine showed a significantly superior effect compared with 2v-HPV and 4v-HPV vaccines in preventing HPV 31/33/45/52/58 infections. Although 2v-HPV and 4v-HPV vaccines provided some cross-protection against HPV 31/33/45/52/58 infections, the effect was significant only on HPV 31 infection. For HPV 16 and 18, neither statistically significant nor small differences were found in the prevention of HPV infection among the 2v-HPV, 4v-HPV, and 9v-HPV vaccines.

CONCLUSION

Our study complements previous understanding of how the effect of HPV vaccines differs according to the HPV genotype. This is important because HPV genotype prevalence varies among countries. We advocate for continued efforts in vaccinating against HPV, while public health agencies should consider the difference in the vaccine effect and HPV genotype prevalence when implementing HPV vaccination in public vaccination programs.

High rate of non-vaccine targeted high-risk HPV genotypes circulate among women in Eastern Ethiopia

The World Health Organization [WHO] recommends a genotype-specific human papillomavirus [HPV] vaccination as a primary prevention strategy to control the burden of cervical cancer globally. In Ethiopia, where the non-vaccine-targeted HPV genotypes have not been adequately studied, a vaccination initiative was launched in 2018 targeting HPV-6,-11, -16, and -18 for girls aged 14-18 years. The co-existence of both vaccine-targeted and non-targeted genotypes is a serious concern, as it can accelerate cancer progression. Therefore, this study was conducted to determine the prevalence of non-vaccine-targeted HPV genotypes and assess the level of multiple infections with other genotypes in eastern Ethiopia. A health facility-based cross-sectional study including 110 women with positive HPV DNA results was conducted from April to August 2021. A structured questionnaire to collect demographic and clinical data was used. Cervical swabs were collected using L-shaped FLOQSwabs. Women's cytological profile was determined based on Pap smear test results. An automated nucleic acid extraction system using STARMag 96 ProPrep Universal Extraction Kit was utilized following the manufacturer's protocol. An amplification assay in real-time was employed to amplify and identify the HPV Late 1 [L1] gene, which is utilized for genotyping purposes. Following this, the collected data was entered into Epi data version 3.1 software, and the analysis was performed using STATA version 14. A total of 110 women [age range 30-60 years, mean age = 36.5 years and SD ± 6.9] had positive HPV DNA results and were included in the study. Among these, 108 women had valid co-testing [Pap test and HPV DNA test] results for further analysis, and the results of the remaining 2 women were rejected. Overall, the prevalence of non-vaccine-targeted HPV was 56 (51.8%, 95%CI [0.42, 0.61]), of which 28 women (25.4%, 95%CI [0.18, 0.34]) had a single non-vaccine HPV genotype infection. The remaining 29 women (26.4%, 95% CI: 0.190-0.355) experienced multiple infections. The non-vaccine-targeted genotypes of HPV-35 accounted for 11 cases (10%, 95%CI [0.06, 0.17]), HPV-68 was detected in 9 women (8.2%, 95%CI [0.04, 0.15]), HPV-56 and HPV-66 were both found in 8 cases each (7.3%, 95%CI [0.04, 0.14]) of the total. In addition, out of these 108 women, 93 (86.1%, 95%CI [0.78, 0.91]) had low-grade squamous intraepithelial lesions, 13 (12%, 95%CI [0.07, 0.20]) no intraepithelial lesion or malignancy, and two (1.9%, 95%CI [0.01, 0.07]) high-grade squamous intraepithelial lesions. Furthermore, there was no statistical difference [p = 0.755] between vaccine-targeted and non-vaccine-targeted genotypes as the primary cause of cervical lesions. In conclusion, the findings of the present study highlight the existence of a notable prevalence of multiple infections caused by non-vaccine-targeted HPV genotypes. Therefore, it is recommended that both the Federal and regional health bureaus to evaluate the range of hr HPV genotypes protected by the current HPV vaccine and explore the option of transitioning from the quadrivalent HPV vaccine to a novavalent vaccine that includes seven high-risk HPV genotypes.

Cost-effectiveness of human papillomavirus (HPV) vaccination in Burkina Faso: a modelling study

BACKGROUND

Africa has some of the highest cervical cancer incidence and mortality rates globally. Burkina Faso launched a human papillomavirus (HPV) vaccination programme for 9-year-old girls in 2022 with support from Gavi, the Vaccine Alliance (Gavi). An economic evaluation of HPV vaccination is required to help sustain investment and inform decisions about optimal HPV vaccine choices.

METHODS

We used a proportionate outcomes static cohort model to evaluate the potential impact and cost-effectiveness of HPV vaccination for 9-year-old girls over a ten-year period (2022-2031) in Burkina Faso. The primary outcome measure was the cost (2022 US$) per disability-adjusted life year (DALY) averted from a limited societal perspective (including all vaccine costs borne by the government and Gavi, radiation therapy costs borne by the government, and all other direct medical costs borne by patients and their families). We evaluated four vaccines (CERVARIX®, CECOLIN®, GARDASIL-4®, GARDASIL-9®), comparing each to no vaccination (and no change in existing cervical cancer screening and treatment strategies) and to each other. We combined local estimates of HPV type distribution, healthcare costs, vaccine coverage and costs with GLOBOCAN 2020 disease burden data and clinical trial efficacy data. We ran deterministic and probabilistic uncertainty analyses.

RESULTS

HPV vaccination could prevent 37-72% of cervical cancer cases and deaths. CECOLIN® had the most favourable cost-effectiveness (cost per DALY averted < 0.27 times the national gross domestic product [GDP] per capita). When cross-protection was included, CECOLIN® remained the most cost-effective (cost per DALY averted < 0.20 times the national GDP per capita), but CERVARIX® provided greater health benefits (66% vs. 48% reduction in cervical cancer cases and deaths) with similar cost-effectiveness (cost per DALY averted < 0.28 times the national GDP per capita, with CECOLIN® as the comparator). We estimated the annual cost of the vaccination programme at US$ 2.9, 4.1, 4.4 and 19.8 million for CECOLIN®, GARDASIL-4®, CERVARIX® and GARDASIL-9®, respectively. A single dose strategy reduced costs and improved cost-effectiveness by more than half.

CONCLUSION

HPV vaccination is cost-effective in Burkina Faso from a limited societal perspective. A single dose strategy and/or alternative Gavi-supported HPV vaccines could further improve cost-effectiveness.

The impact of over ten years of HPV vaccination in England: Surveillance of type-specific HPV in young sexually active females

INTRODUCTION

The UK national human papillomavirus (HPV) vaccination programme was introduced in 2008 using the bivalent HPV16/18 vaccine, changing to the quadrivalent HPV6/11/16/18 vaccine from 2012. We provide an analysis of type-specific HPV prevalence in young sexually active females in England to end 2020 (when the first routinely HPV vaccinated females were reaching 25 years of age and entering the National Health Service Cervical Screening Programme), showing the impact of over ten years of high coverage HPV vaccination.

METHODS

Residual vulvovaginal swabs (VVS) were collected from 16 to 24 year old women attending for chlamydia screening between 2010 and 2020, anonymised and tested for type-specific HPV DNA. Trends in vaccine and non-vaccine HPV type prevalence were compared over time and association with vaccination coverage was evaluated within the post-vaccination period.

RESULTS

A total of 21,168 eligible VVS specimens were tested for HPV DNA. The prevalence of HPV16/18 in sexually active 16-18 year old females who were offered vaccination aged 12-13 years was <1% in the most recent years tested, compared to over 15% prior to the vaccination programme in 2008. The magnitude of these decreases also suggests reduced transmission is offering some herd protection to unvaccinated females. HPV31/33/45 prevalence also steadily decreased, providing evidence of cross-protection. HPV6/11 prevalence remained stable during the bivalent vaccine period, with more recent declines, as expected due to the use of the quadrivalent vaccine. There has been no substantive increase in the prevalence of other high-risk (HR) HPV types.

DISCUSSION

More than ten years of high coverage HPV vaccination in adolescent females in England has delivered dramatic declines in the prevalence of HPV vaccine-types and closely related HPV types in females in the vaccine eligible age group, and no indication of type replacement. These findings should enable confidence in planning for cervical screening of these females, and in predicting declines in HPV-related cancers.

Effects of 2 and 3 Vaccinations With the Bivalent Human Papillomavirus (HPV) Vaccine on the Prevalence and Load of HPV in Clearing and Persistent Infections in Young Women

BACKGROUND

Human papillomavirus (HPV) viral load (VL) is associated with persistence, which increases cervical cancer risk. The bivalent vaccine protects against oncogenic HPV-16/18 and cross-protects against several nonvaccine types. We examined the effect of 2-dose (2D) and 3-dose (3D) vaccination on HPV prevalence and VL in clearing infections and persistent infections, 6 years and 12 years postvaccination, respectively.

METHODS

Vaginal swabs collected from the "HPV Amongst Vaccinated and Non-vaccinated Adolescents" study (HAVANA, 3D-eligible) and HAVANA-2 (2D-eligble) participants were genotyped for HPV with the SPF10-DEIA-LiPA25 system. HPV VL was measured with type-specific quantitative polymerase chain reaction (qPCR).

RESULTS

HPV-16, -18, -31, -33, and -45 clearing and/or persistent infection prevalence and HPV-16, -18, and -31 VLs in clearing infections were significantly reduced in 3D-vaccinated women compared to unvaccinated women. Except for HPV-11 and -59 clearing infections, no significant VL differences were observed among vaccinated women, ≤6 and >6 years post-vaccination. Infection numbers were low in 2D-eligible women, with no HPV-16/18 in vaccinated women. No VL differences for the remaining types were found.

CONCLUSIONS

3D vaccination reduces HPV prevalence in clearing infections and persistent infections and decreases HPV VLs in clearing infections, 12 years post-vaccination for vaccine and several nonvaccine types. 2D-eligible women had low infection numbers, with no HPV-16/18 among vaccinated women.

Impact, cost-effectiveness, and budget implications of HPV vaccination in Kenya: A modelling study

BACKGROUND

Sub-Saharan Africa has the highest rate of cervical cancer cases and deaths worldwide. Kenya introduced a quadrivalent HPV vaccine (GARDASIL, hereafter referred to as GARDASIL-4) for ten-year-old girls in late 2019 with donor support from Gavi, the Vaccine Alliance. As Kenya may soon graduate from Gavi support, it is important to evaluate the potential cost-effectiveness and budget impact of the current HPV vaccine, and potential alternatives.

METHODS

We used a proportionate outcomes static cohort model to evaluate the annual budget impact and lifetime cost-effectiveness of vaccinating ten-year-old girls over the period 2020-2029. We included a catch-up campaign for girls aged 11-14 years in 2020. We estimated cervical cancer cases, deaths, disability adjusted life years (DALYs), and healthcare costs (government and societal perspective) expected to occur with and without vaccination over the lifetimes of each cohort of vaccinated girls. For each of the four products available globally (CECOLIN©, CERVARIX©, GARDASIL-4©, and GARDASIL-9 ©), we estimated the cost (2021 US$) per DALY averted compared to no vaccine and to each other. Model inputs were obtained from published sources, as well as local stakeholders.

RESULTS

We estimated 320,000 cases and 225,000 deaths attributed to cervical cancer over the lifetimes of the 14 evaluated birth cohorts. HPV vaccination could reduce this burden by 42-60 %. Without cross-protection, CECOLIN had the lowest net cost and most attractive cost-effectiveness. With cross-protection, CERVARIX was the most cost-effective. Under either scenario the most cost-effective vaccine had a 100 % probability of being cost-effective at a willingness-to-pay threshold of US$ 100 (5 % of Kenya's national gross domestic product per capita) compared to no vaccination. Should Kenya reach its target of 90 % coverage and graduate from Gavi support, the undiscounted annual vaccine program cost could exceed US$ 10 million per year. For all three vaccines currently supported by Gavi, a single-dose strategy would be cost-saving compared to no vaccination.

CONCLUSION

HPV vaccination for girls is highly cost-effective in Kenya. Compared to GARDASIL-4, alternative products could provide similar or greater health benefits at lower net costs. Substantial government funding will be required to reach and sustain coverage targets as Kenya graduates from Gavi support. A single dose strategy is likely to have similar benefits for less cost.

Impact and Cost-Effectiveness of Alternative Human Papillomavirus Vaccines for Preadolescent Girls in Mozambique: A Modelling Study

Mozambique has one of the highest rates of cervical cancer in the world. Human papillomavirus (HPV) vaccination was introduced in 2021. This study evaluated the health and economic impact of the current HPV vaccine (GARDASIL^® hereafter referred to as GARDASIL-4) and two other vaccines (CECOLIN^® and CERVARIX^®) that could be used in the future. A static cohort model was used to estimate the costs and benefits of vaccinating girls in Mozambique over the period 2022-2031. The primary outcome measure was the incremental cost per disability-adjusted life-year averted from a government perspective. We conducted deterministic and probabilistic sensitivity analyses. Without cross-protection, all three vaccines averted approximately 54% cervical cancer cases and deaths. With cross-protection, CERVARIX averted 70% of cases and deaths. Without Gavi support, the discounted vaccine program costs ranged from 60 million to 81 million USD. Vaccine program costs were approximately 37 million USD for all vaccines with Gavi support. Without cross-protection, CECOLIN was dominant, being cost-effective with or without Gavi support. With cross-protection and Gavi support, CERVARIX was dominant and cost-saving. With cross-protection and no Gavi support, CECOLIN had the most favorable cost-effectiveness ratio. Conclusions: At a willingness-to-pay (WTP) threshold set at 35% of Gross Domestic Product (GDP) per capita, HPV vaccination is cost-effective in Mozambique. The optimal vaccine choice depends on cross-protection assumptions.

Virus-like Particle Vaccines and Platforms for Vaccine Development

Virus-like particles (VLPs) have gained a lot of interest within the past two decades. The use of VLP-based vaccines to protect against three infectious agents-hepatitis B virus, human papillomavirus, and hepatitis E virus-has been approved; they are very efficacious and offer long-lasting immune responses. Besides these, VLPs from other viral infectious agents (that infect humans, animals, plants, and bacteria) are under development. These VLPs, especially those from human and animal viruses, serve as stand-alone vaccines to protect against viruses from which the VLPs were derived. Additionally, VLPs, including those derived from plant and bacterial viruses, serve as platforms upon which to display foreign peptide antigens from other infectious agents or metabolic diseases such as cancer, i.e., they can be used to develop chimeric VLPs. The goal of chimeric VLPs is to enhance the immunogenicity of foreign peptides displayed on VLPs and not necessarily the platforms. This review provides a summary of VLP vaccines for human and veterinary use that have been approved and those that are under development. Furthermore, this review summarizes chimeric VLP vaccines that have been developed and tested in pre-clinical studies. Finally, the review concludes with a snapshot of the advantages of VLP-based vaccines such as hybrid/mosaic VLPs over conventional vaccine approaches such as live-attenuated and inactivated vaccines.

Associations of human papillomavirus genotypes and cervical vascular abnormality in a cohort of women underwent colposcopy, a retrospective study of 6716 patients

Aims

Abnormal vessel patterns are specific signs in patients with early cervical abnormality and cervical cancer(CC) by colposcopy, but the impact of human papillomavirus (HPV) infections on abnormal vessel patterns remains unknown.

Methods

A total of 6716 female patients with HPV infections or cytological abnormalities who underwent a colposcopy following abnormal CC screening results were included in the study. The final pathological diagnosis was confirmed to be the most severe pathological grade across cervical biopsy, endocervical canal curettage (ECC) and conization. Univariate and multivariate logistic regression analyses were used to investigate the association between HPV infections and abnormal vessel patterns, adjusting for age, gravidity and parity.

Results

There were 6124 normal vascular cases by colposcopy and 592 cases with cervical vascular abnormality. The prevalence of HPV infections was 4284 (70%) in normal patients, and the prevalence of HPV infections was 479 (80%) in cervical vascular abnormality patients. HPV high-risk type 16 infection alone increased the risk of cervical heteromorphic blood vessels (aOR=3.66, 95%CI: 2.54~5.27). HPV 16 and 33 alone (other than the commonly recognized subtype of 18) or coinfection of these two genotypes could increase the risk of cervical punctate vascular and cervical vascular mosaic features and abnormal cervical blood vessels. An increased risk of abnormal cervical lesions was observed for HPV 16 and 33 alone or combined in coinfection compared to the negative group. The risk of cervical vascular abnormality was increased 10-fold by coinfection with HPV 16 and 33 (aOR=10.67, 95% CI: 4.54~25.09, P&lt;0.001). HPV 16, 33 alone or combined in coinfection were associated with an increased risk of lesions more advanced than high-grade squamous intraepithelial lesion (HSIL) when compared to the negative group. The risk of lesions more advanced than HSIL was up to 26-fold higher in the coinfection with HPV 16 and 33 group than in the negative group (aOR=26.23, 95%CI: 11.23~61.27, P&lt;0.001).

Conclusion

HPV16 and 33 are the most dangerous HPV genotypes correlated with abnormal vascular patterns. Combined HPV16 and HPV33 infection increases the risk of abnormal vascular patterns. Combined HPV16 and HPV33 infection increases the risk of developing HSIL+.

Differences in HPV-specific antibody Fc-effector functions following Gardasil® and Cervarix® vaccination

Gardasil® (Merck) and Cervarix® (GlaxoSmithKline) both provide protection against infection with Human Papillomavirus 16 (HPV16) and Human Papillomavirus 18 (HPV18), that account for around 70% of cervical cancers. Both vaccines have been shown to induce high levels of neutralizing antibodies and are known to protect against progression beyond cervical intraepithelial neoplasia grade 2 (CIN2+), although Cervarix® has been linked to enhanced protection from progression. However, beyond the transmission-blocking activity of neutralizing antibodies against HPV, no clear correlate of protection has been defined that may explain persistent control and clearance elicited by HPV vaccines. Beyond blocking, antibodies contribute to antiviral activity via the recruitment of the cytotoxic and opsonophagocytic power of the immune system. Thus, here, we used systems serology to comprehensively profile Gardasil®- and Cervarix®- induced antibody subclass, isotype, Fc-receptor binding, and Fc-effector functions against the HPV16 and HPV18 major capsid protein (L1). Overall, both vaccines induced robust functional humoral immune responses against both HPV16 and HPV18. However, Cervarix® elicited higher IgG3 and antibody-dependent complement activating responses, and an overall more coordinated response between HPV16 and 18 compared to Gardasil®, potentially related to the distinct adjuvants delivered with the vaccines. Thus, these data point to robust Fc-effector functions induced by both Gardasil® and Cervarix®, albeit with enhanced coordination observed with Cervarix®, potentially underlying immunological correlates of post-infection control of HPV.

Experimental Validation of MHC Class I and II Peptide-Based Potential Vaccine Candidates for Human Papilloma Virus Using Sprague-Dawly Models

Human papilloma virus (HPV) causes cervical and many other cancers. Recent trend in vaccine design is shifted toward epitope-based developments that are more specific, safe, and easy to produce. In this study, we predicted eight immunogenic peptides of CD4+ and CD8+ T-lymphocytes (MHC class I and II as M1 and M2) including early proteins (E2 and E6), major (L1) and minor capsid protein (L2). Male and female Sprague Dawly rats in groups were immunized with each synthetic peptide. L1M1, L1M2, L2M1, and L2M2 induced significant immunogenic response compared to E2M1, E2M2, E6M1 and E6M2. We observed optimal titer of IgG antibodies (>1.25 g/L), interferon-γ (>64 ng/L), and granzyme-B (>40 pg/mL) compared to control at second booster dose (240 µg/500 µL). The induction of peptide-specific IgG antibodies in immunized rats indicates the T-cell dependent B-lymphocyte activation. A substantial CD4+ and CD8+ cell count was observed at 240 µg/500 µL. In male and female rats, CD8+ cell count for L1 and L2 peptide is 3000 and 3118, and CD4+ is 3369 and 3484 respectively compared to control. In conclusion, we demonstrated that L1M1, L1M2, L2M1, L2M2 are likely to contain potential epitopes for induction of immune responses supporting the feasibility of peptide-based vaccine development for HPV.

Exploiting RIG-I-like receptor pathway for cancer immunotherapy

RIG-I-like receptors (RLRs) are intracellular pattern recognition receptors that detect viral or bacterial infection and induce host innate immune responses. The RLRs family comprises retinoic acid-inducible gene 1 (RIG-I), melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2) that have distinctive features. These receptors not only recognize RNA intermediates from viruses and bacteria, but also interact with endogenous RNA such as the mislocalized mitochondrial RNA, the aberrantly reactivated repetitive or transposable elements in the human genome. Evasion of RLRs-mediated immune response may lead to sustained infection, defective host immunity and carcinogenesis. Therapeutic targeting RLRs may not only provoke anti-infection effects, but also induce anticancer immunity or sensitize "immune-cold" tumors to immune checkpoint blockade. In this review, we summarize the current knowledge of RLRs signaling and discuss the rationale for therapeutic targeting RLRs in cancer. We describe how RLRs can be activated by synthetic RNA, oncolytic viruses, viral mimicry and radio-chemotherapy, and how the RNA agonists of RLRs can be systemically delivered in vivo. The integration of RLRs agonism with RNA interference or CAR-T cells provides new dimensions that complement cancer immunotherapy. Moreover, we update the progress of recent clinical trials for cancer therapy involving RLRs activation and immune modulation. Further studies of the mechanisms underlying RLRs signaling will shed new light on the development of cancer therapeutics. Manipulation of RLRs signaling represents an opportunity for clinically relevant cancer therapy. Addressing the challenges in this field will help develop future generations of cancer immunotherapy.

The second HPV serology meeting: Progress and challenges in standardization of human papillomavirus serology assays

The HPV Serology Laboratory in the Frederick National Laboratory for Cancer Research is working in partnership with the scientific community with the goal of standardizing and harmonizing current HPV serology assay platforms in response to the increasing number of immunobridging trials relying on serology data for approval of new vaccine dosing schedules and new formulations. A virtual meeting was held on June 29-30, 2021, to review the progress of the standardization initiative thus far and to bridge scientific gaps and outstanding questions. The main aims and outcomes of the meeting were to discuss: 1) standardization of assays and reagents; 2) International Standard calibration procedures; 3) assay cut-off values; 4) current immunobridging clinical trials; and 5) gaps and challenges in standardization of HPV serology.

Ability of epidemiological studies to monitor HPV post-vaccination dynamics: a simulation study

Genital human papillomavirus (HPV) infections are caused by a broad diversity of genotypes. As available vaccines target a subgroup of these genotypes, monitoring transmission dynamics of nonvaccine genotypes is essential. After reviewing the epidemiological literature on study designs aiming to monitor those dynamics, we evaluated their abilities to detect HPV-prevalence changes following vaccine introduction. We developed an agent-based model to simulate HPV transmission in a heterosexual population under various scenarios of vaccine coverage and genotypic interaction, and reproduced two study designs: post-vs.-prevaccine and vaccinated-vs.-unvaccinated comparisons. We calculated the total sample size required to detect statistically significant prevalence differences at the 5% significance level and 80% power. Although a decrease in vaccine-genotype prevalence was detectable as early as 1 year after vaccine introduction, simulations indicated that the indirect impact on nonvaccine-genotype prevalence (a decrease under synergistic interaction or an increase under competitive interaction) would only be measurable after >10 years whatever the vaccine coverage. Sample sizes required for nonvaccine genotypes were >5 times greater than for vaccine genotypes and tended to be smaller in the post-vs.-prevaccine than in the vaccinated-vs.-unvaccinated design. These results highlight that previously published epidemiological studies were not powerful enough to efficiently detect changes in nonvaccine-genotype prevalence.

Head-to-head comparison of genotyping of human papillomavirus by real-time multiplex PCR assay using type-specific primers and SPF10-PCR-based line probe assay

The SPF10-polymerase chain reaction (PCR)-based line probe assay (LiPA-25) with high analytical sensitivity and specificity for human papillomavirus (HPV) genotyping in clinical samples has been widely used in vaccine and epidemiologic studies. A real-time multiplex PCR assay using type-specific primers (Hybribio-23) with low workload and cost has been developed recently. The study aimed to compare the performance of LiPA-25 and Hybribio-23 in selected 1731 cervical swab and 117 tissue samples, with a focus on 20 common HPV types (14 high-risk: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68/73; 6 low-risk: 6, 11, 42, 43, 44, and 53). The level of agreement of two assays was determined using Cohen's Kappa (κ) statistics. A total of 1296 (74.9%) swab samples were identified as HPV-positive by Hybribio-23 or LiPA-25, of which 814 (62.8%) samples exhibited concordant, 358 (27.6%) showed additional or fewer types (compatible), and 124 (9.6%) were discordant. In addition, the two assays showed a perfect agreement for 20 HPV-combined detection (κ = 0.838) and 17 individual HPV types (all κ > 0.800), a good agreement for HPV31 (κ = 0.792) and 43 (κ = 0.696), and a moderate agreement for HPV42 (κ = 0.504). Hybribio-23 was significantly more sensitive for HPV58, 59, 68/73, 42, 43, and 44, and less sensitive for HPV35 and 66 than LiPA-25 (McNemar's test: all p < 0.05). For 117 HPV-positive tissue specimens, the identification of genotypes was 85.2% identical, 12.2% compatible, and only 2.6% discordant. The agreement for HPV31 (κ = 0.786), 68/73 (κ = 0.742), and HPV53 (κ = 0.742) was good, while for other types (all κ > 0.853) and 20 HPV-combined detection (κ = 0.936) was perfect (all p > 0.05). In conclusion, Hybribio-23 and LiPA-25 are comparable. Hybribio-23 could be used for the detection and genotyping of HPV in cervical samples for epidemiological and vaccine studies worldwide.

Head-to-head comparison of genotyping of human papillomavirus by GP5+/6+-PCR-based reverse dot blot hybridization assay and SPF10-PCR-based line probe assay

The SPF10-PCR-based line probe assay (LiPA-25) for human papillomavirus (HPV) genotyping with high analytical sensitivity and specificity was widely used in HPV vaccine clinical trials and epidemiologic studies. In the study, we aimed to compare a novel GP5+/6+-PCR-based reverse dot blot hybridization assay (Yaneng-23) with LiPA-25. The performance of two assays was evaluated in 1735 cervical swab and 117 tissue samples, with a focus on 19 common HPV types (14 high-risk: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68/73; 5 low-risk: 6, 11, 42, 43, and 53). A total of 1197 (69.0%) swab samples were identified as HPV-positive by two assays. Of these, 878 (73.4%) samples displayed absolute agreement (concordant), 255 (21.3%) showed additional or fewer types (compatible), and the remaining 64 (5.3%) samples were discordant. Additionally, the two assays showed an excellent strength of agreement for 19 HPV-combined detection (κ = 0.886) and 17 individual HPV types (all κ > 0.800), and displayed a good agreement for HPV39 (κ = 0.780) and 42 (κ = 0.699). Yaneng-23 was more sensitive than LiPA-25 for HPV58, 59, 68/73, 42, 43 and 53 (McNemar's test: all p < 0.05), while LiPA-25 was more sensitive for HPV31, 39, 52, and 66 than Yaneng-23 (all p < 0.05). In 113 HPV-positive tissue specimens, the identification of genotypes was 82.3% identical and 17.7% compatible. The agreement between the tests for HPV45 (κ = 0.796) and 51 (κ = 0.742) was good, and for other types (all κ > 0.843) and 19 HPV-combined detection (κ = 0.929) was perfect (all p > 0.05). In conclusion, Yaneng-23 and LiPA-25 are comparable. Yaneng-23 could be used for the detection and genotyping of HPV in cervical samples for epidemiological and vaccine studies worldwide.

Updates on HPV Vaccination

Cervical cancer still poses a significant global challenge. Developed countries have mitigated this challenge by the introduction of structured screening programmes and, more recently, the HPV vaccine. Countries that have successfully introduced national HPV vaccination programmes are on course for cervical cancer elimination in a few decades. In developing countries that lack structured screening and HPV vaccination programmes, cervical cancer remains a major cause of morbidity and mortality. The HPV vaccine is key to addressing the disproportionate distribution of cervical cancer incidence, with much to be gained from increasing vaccine coverage and uptake globally. This review covers the history and science of the HPV vaccine, its efficacy, effectiveness and safety, and some of the considerations and challenges posed to the achievement of global HPV vaccination coverage and the consequent elimination of cervical cancer.

Pseudotyped Virus for Papillomavirus

Papillomavirus is difficult to culture in vitro, which limits its related research. The development of pseudotyped virus technology provides a valuable research tool for virus infectivity research, vaccine evaluation, infection inhibitor evaluation, and so on. Depending on the application fields, different measures have been developed to generate various kinds of pseudotyped papillomavirus. L1-based and L2-based HPV vaccines should be evaluated using different pseudotyped virus system. Pseudotyped papillomavirus animal models need high-titer pseudotyped virus and unique handling procedure to generate robust results. This paper reviewed the development, optimization, standardization, and application of various pseudotyped papillomavirus methods.

Comparative efficacy of human papillomavirus vaccines: systematic review and network meta-analysis

OBJECTIVES

Despite their use, differences in human papillomavirus (HPV) vaccine efficacies remain uncertain. This study assesses efficacy differences among bivalent, quadrivalent, and nine-valent HPV (2vHPV, 4vHPV, and 9vHPV) vaccines.

METHODS

PubMed, Web of Science, Embase, and the Cochrane Library were searched for randomized controlled trials comparing HPV vaccine efficacy against persistent infection (≥6 months) and cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Network meta-analysis yielded direct and indirect comparisons. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were reported, and robustness was evaluated via sensitivity analysis.

RESULTS

In 11 randomized controlled trials with 58,881 healthy women, for persistent infection with HPV 16, 9vHPV was most effective at 97% (RR = 0.03, 95% CI: 0.01-0.08); for HPV 18, 2vHPV (Cecolin) was most effective at 98% (RR = 0.02, 95% CI: 0.00-0.29); for CIN2+ associated with HPV 16 and 18, 4vHPV was most effective at 99% (RR = 0.01, 95% CI: 0.00-0.10) and 97% (RR = 0.03, 95% CI: 0.00-0.45), respectively; for persistent infection with HPV 31, 33, 45, 52, and 58, 9vHPV was ≥ 95% effective; both 2vHPV vaccines were cross-effective against HPV 31, 33, and 45; and 4vHPV was cross-effective against HPV 31.

CONCLUSIONS

HPV vaccine efficacies differ for different HPV types. Additional data are needed to determine the cross-efficacy of 2vHPV (Cecolin).

Prevalence of multiple human papillomavirus infections and association with cervical lesions among outpatients in Fujian, China: A cross-sectional study

Multiple human papillomavirus (HPV) infections are common, but their impact on cervical lesions remains controversial. A total of 6225 female patients who underwent colposcopies/conization following abnormal cervical cancer screening results were included in the study. The final pathological diagnosis was determined by the most severe pathological grade among the cervical biopsy, endocervical curettage, and conization. Univariate and multivariate logistic regression analyses were used to investigate the association between multiple HPV infections and cervical lesions, adjusting for age, HPV genotype, gravidity and parity. In total, 33.3% (n = 2076) of the study population was infected with multiple HPV genotypes. Multiple HPV infections were more prevalent in patients younger than 25 years and older than 55 years, with the rate of multiple HPV infections at 52.8% and 44.3%, respectively. HPV16\52\18\58 are the most common HPV genotypes and usually appear as a single infection. Compared to single HR-HPV infection, multiple HR-HPV infections do not increase the risk of HSIL+, while single HR-HPV coinfected with LR-HPV seems to reduce the risk of HSIL+ (odds ratio = 0.515, confidence interval: 0.370-0.719, p < 0.001). Multiple HR-HPV infections cannot be risk-stratified for triage of HR-HPV-positive women.

Cost-Benefit Analysis of Human Papillomavirus Vaccine in Iran

Despite increasing global attention to the national human papillomavirus (HPV) immunization program, this program is controversial in Iran. Evidence indicates that HPV vaccination is not cost-effective in Iran. Using cost-effectiveness analysis for decision-making about public health interventions such as vaccination is controversial because its potential benefits may not fit this framework. This study aimed to evaluate the economic effects of the HPV vaccination by cost-benefit analysis (CBA) using bivalent and quadrivalent in Iran in 2020. We performed a CBA from a societal perspective. We used two approaches of the vaccine's economic benefits: willingness to pay by discrete choice experiment and cost of illness. Costs only included the vaccine cost. The cost of two doses of bivalent and quadrivalent vaccines were US $29 and the US $151, respectively (US $1 = IRR 42,000). The benefits of bivalent and quadrivalent vaccines were US $ - 432, US $380 per person using the willingness to pay approach, and they were US $7375 and US $6590 thorough cost-of-illness approach. The cost-benefit ratio (CBR) of bivalent and quadrivalent vaccines was - 15.11 and 2.51 by the willingness to pay approach, and 258.12 and 43.51 by the cost of illness approach. This study confirms the benefits of the national bivalent and quadrivalent vaccination programs and provides reliable evidence for policy-makers programming HPV vaccination.

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.

Case report: Anti-GAD65 antibody-associated autoimmune encephalitis following HPV vaccination

Human papillomavirus (HPV) infection is a sexually transmitted disease that may lead to cervical cancer. HPV vaccines have been implemented widely to prevent this. While generally few complications of vaccination are reported, there have been occasional reports of adverse reactions post-vaccination. The safety profile of the HPV vaccine is reassuring. However, since its introduction, several serious post-vaccination central nervous system complications have been reported; however, causality has not been established. Herein, we describe a 39-year-old woman who developed seizures and experienced a rapid decline in memory shortly after her first dose of the HPV vaccine. Cranial magnetic resonance imaging and cerebrospinal fluid analysis were performed, and the patient was diagnosed with anti-glutamic acid decarboxylase 65 (anti-GAD65) antibody-associated autoimmune encephalitis. She responded well to high-dose glucocorticoids. Four-month follow-up revealed full recovery and absence of recurrence. Since the HPV vaccine is administered worldwide, this case should raise clinicians' awareness regarding the possible CNS complications related to vaccinations, such as anti-GAD65 antibody-associated AE.

Head-to-head comparison of 7 high-sensitive human papillomavirus nucleic acid detection technologies with the SPF10 LiPA-25 system

Background

The SPF10 LiPA-25 system for human papillomavirus (HPV) detection with high analytical performance is widely used in HPV vaccine clinical trials. To develop and evaluate more valent HPV vaccines, other comparable methods with simpler operations are needed.

Methods

The performance of the LiPA-25 against that of other 7 assays, including 4 systems based on reverse hybridization (Bohui-24, Yaneng-23, Tellgen-27, and Hybribio-16) and 3 real-time polymerase chain reaction (PCR) assays (Hybribio-23, Bioperfectus-21, and Sansure-26), was evaluated in selected 1726 cervical swab and 56 biopsy samples. A total of 15 HPV genotypes (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 66) were considered for comparison for each HPV type.

Results

Among the swab samples, compared to LiPA-25, compatible genotypes were observed in 94.1% of samples for Hybribio-23, 92.8% for Yaneng-23, 92.6% for Bioperfectus-21, 92.4% for Hybribio-16, 91.3% for Sansure-26, 89.7% for Bohui-24, and 88.0% for Tellgen-27. The highest overall agreement of the 15 HPV genotypes combined was noted for Hybribio-23 (κ = 0.879, McNemar's test: P = 0.136), followed closely by Hybribio-16 (κ = 0.877, P< 0.001), Yaneng-23 (κ = 0.871, P < 0.001), Bioperfectus-21 (κ = 0.848, P < 0.001), Bohui-24 (κ = 0.847, P < 0.001), Tellgen-27 (κ = 0.831, P < 0.001), and Sansure-26 (κ = 0.826, P < 0.001). Additionally, these systems were also highly consistent with LiPA-25 for biopsy specimens (all, κ > 0.897).

Conclusions

The levels of agreement for the detection of 15 HPV types between other 7 assays and LiPA-25 were all good, and Hybribio-23 was most comparable to LiPA-25. The testing operation of HPV genotyping should also be considered for vaccine and epidemiological studies.

Single-dose HPV vaccine immunity: is there a role for non-neutralizing antibodies?

A single dose of human papillomavirus (HPV) vaccine against HPV infection (prerequisite for cervical cancer) appears to be as efficacious as two or three doses, despite inducing lower antibody titers. Neutralizing antibodies are thought to be the primary mediator of protection, but the threshold for protection is unknown. Antibody functions beyond neutralization have not been explored for HPV vaccines. Here, we discuss the immune mechanisms of HPV vaccines, with a focus on non-neutralizing antibody effector functions. In the context of single-dose HPV vaccination where antibody is limiting, we propose that non-neutralizing antibody functions may contribute to preventing HPV infection. Understanding the immunological basis of protection for single-dose HPV vaccination will provide a rationale for implementing single-dose HPV vaccine regimens.

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.

Resolving adjuvant mode of action to enhance vaccine efficacy

Adjuvants are a miscellaneous range of molecules and materials that can enhance the magnitude, functionality, breadth and durability of immune responses. Despite the multiplicity of compounds with adjuvant properties, less than a dozen are in clinical use in vaccines against infectious diseases. While many factors have contributed to their slow development, among the major challenges are the high safety and efficacy standards set by current adjuvants in human vaccines and our limited understanding of how adjuvants mediate their effects. This review outlines why it is so difficult to elucidate their mechanism of action, highlights areas that require in-depth research and discusses recent advancements that are revitalising adjuvant development. It is hoped that a fuller understanding of adjuvant sensing, signalling and function will facilitate the design of vaccines that promote sustained protective immunity against challenging bacterial and viral pathogens.

Disparities in Human Papillomavirus vaccination coverage among adolescents in Australia: A geospatial analysis

AIM

This ecological study aimed to examine the geographic patterns in Human Papillomavirus (HPV) vaccination rates among boys and girls aged 15 years across locations in Australia, in addition to assessing contextual area-level factors that may explain the variations in HPV vaccination coverage.

METHODS

Aggregate HPV vaccination data for Australian girls and boys aged 15 years from 2015 to 16 was obtained from the Australian Institute of Health and Welfare for each Statistical Area level 4 (SA4). A Gradient Boosting Machine learning model was applied to assess the predictors' importance for the study outcomes. Geographically weighted regression (GWR) models were run to assess whether substantially different relationships between predictors and outcomes occur at different locations in space.

RESULTS

Completed HPV vaccination across the 88 SA4 regions ranged from 57.6% to 90.6% among girls, and from 53.6% to 85.5% among boys. The 2016 SEIFA Index of Economic Resources was the variable with the highest contribution to the predictions of both girls' and boys' HPV vaccination rates. Selected predictors explained 45% and 72% of the geographic variance in vaccination rates among boys and girls, respectively. Normalised coefficients for both GWR models showed a high variation in the associations between predictors and HPV vaccination rates across regions.

CONCLUSION

Socioeconomic and education factors were important predictors for HPV vaccination rates among Australian boys and girls aged 15 years, although no variable presented a uniform effect on HPV vaccination across SA4 regions. Important spatial heterogeneity in the effect of predictors was identified across the study area.

HPV51-associated Leiomyosarcoma: A Novel Class of TP53/RB1-Wildtype Tumor With Predilection for the Female Lower Reproductive Tract

Inactivating mutations in tumor suppressor genes TP53 and RB1 are considered central drivers in leiomyosarcomas (LMSs). In high-risk human papillomavirus (HPV)-related tumors, a similar functional outcome is achieved through oncoproteins E6 and E7, which inactivate the p53 and RB1 proteins, respectively. Here, we hypothesized that HPV infection could provide an alternative mechanism for tumorigenesis in a subset of TP53/RB1-wildtype LMS. We evaluated tumor samples from 2585 consecutive unique patients carrying a diagnosis of gynecologic or soft tissue LMS. Tumor DNA and available RNA were analyzed by hybrid-capture-based next-generation sequencing/comprehensive genomic profiling of 406 genes and transcripts (FoundationOneHeme). Of the initial 2585 cases, we excluded 16 based on the presence of molecular alterations that are considered defining for sarcomas other than LMS. In the remaining 2569 cases, we searched for LMS that were TP53/RB1-wildtype (n=486 of 2569; 18.9%). We also searched LMS tumors for HPV sequences that we then classified into genotypes by de novo assembly of nonhuman sequencing reads followed by alignment to the RefSeq database. Among TP53/RB1-wildtype LMS, we identified 18 unique cases harboring HPV sequences. Surprisingly, most (n=11) were HPV51-positive, and these 11 represented all HPV51-positive tumors in our entire LMS database (n=11 of 2569; 0.4%). The absence of genomic alterations in TP53 or RB1 in HPV51-positive LMS represented a marked difference from HPV51-negative LMS (n=2558; 0% vs. 72% [P<0.00001], 0% vs. 53% [P=0.0002]). In addition, compared with HPV51-negative LMS, HPV51-positive LMS were significantly enriched for genomic alterations in ATRX (55% vs. 24%, P=0.027) and TSC1 (18% vs. 0.6%, P=0.0047). All HPV51-positive LMS were in women; median age was 54 years at surgery (range: 23 to 74 y). All known primary sites were from the gynecologic tract or adjacent anogenital area, including 5 cases of vaginal primary site. Histology was heterogeneous, with evaluable cases showing predominant epithelioid (n=5) and spindle (n=5) morphology. In situ hybridization confirmed the presence of high-risk HPV E6/E7 mRNA in tumor cells in three of three evaluable cases harboring HPV51 genomic sequences. Overall, in our pan-LMS analysis, HPV reads were identified in a subset of TP53/RB1-wildtype LMS. For all HPV51-associated LMS, the striking absence of any detectable TP53 or RB1 mutations and predilection for the female lower reproductive tract supports our hypothesis that high-risk HPV can be an alternative tumorigenic mechanism in this distinct class of LMS.

Vaccine safety in an era of novel vaccines: a proposed research agenda

In this Comment article, Gregory Poland and Richard Kennedy outline the importance of continued funding and infrastructure support for research into vaccine safety to inform public health decisions and increase public trust in new vaccine technologies.

Cost-Effectiveness of Bivalent, Quadrivalent, and Nonavalent HPV Vaccination in South Africa

BACKGROUND AND OBJECTIVES

In South Africa, the prevalence of human papillomavirus (HPV) and associated diseases, such as cervical cancer and genital warts, is among the highest in the world. This study evaluates the cost-effectiveness of bivalent, quadrivalent, and nonavalent HPV vaccination for 9- to 14-year-old girls from the South African healthcare system perspective.

METHODS

A Markov model portraying the natural HPV disease progression from high-risk infection to cervical intraepithelial neoplasia (CIN) I, CIN II/III, or cervical cancer and from low-risk infection to genital warts was built. Transition probability, utility, and efficacy data were sourced from peer-reviewed literature. Vaccination costs were calculated based on the World Health Organization (WHO) guidelines. The model was populated with a cohort of 520,000 9-year-old girls to calculate incremental cost-effectiveness ratios (ICER) in South African Rand (R) per quality-adjusted life-years (QALYs) gained for each vaccination strategy.

RESULTS

All HPV vaccination strategies dominate the no vaccine strategy. Compared with the bivalent vaccine, the nonavalent strategy increases QALYs by 0.14 and costs by R1793 (ICER: R13,013 per QALY) per person, while the quadrivalent vaccination provides -0.02 incremental QALYs and R1748 costs (ICER: -R116,397 per QALY). Consequently, at the South African willingness-to-pay threshold of R23,630 per QALY, nonavalent vaccination is the preferred strategy, with a probability of 90.2%. Scenario analysis demonstrated that results are influenced by vaccine coverage, efficacy, and duration of efficacy.

CONCLUSIONS

The introduction of nonavalent for bivalent HPV vaccination is a cost-effective intervention in South Africa. HPV vaccination should be part of a multifaceted public health strategy entailing screening, condoms, and education of all stakeholders to reduce the significant burden of sexual transmitted diseases in South Africa. Sex-neutral and catch-up vaccinations are subjects for further research.

Phytocompounds from the medicinal and dietary plants: Multi-target agents for cancer prevention and therapy

Cervical cancer is the fourth leading cause of cancer death among women worldwide. Due to cervical cancer's high incidence and mortality, there is an unmet demand for effective diagnostic, therapeutic, and preventive agents. At present, the preferred treatment strategies for advanced metastatic cervical cancer include surgery, radiotherapy, and chemotherapy. However, cervical cancer is gradually developing resistance to chemotherapy, thereby reducing its efficacy. Over the last several decades, phytochemicals, a general term for compounds produced from plants, have gained attention for their role in preventing cervical cancer. This role in cervical cancer prevention has garnered attention on the medicinal properties of fruits and vegetables. Phytochemicals are currently being evaluated for their ability to block proteins involved in carcinogenesis and chemoresistance against cervical cancer. Chemoresistance to cancer drugs like cisplatin, doxorubicin, and 5-fluorouracil has become a significant limitation of drug-based chemotherapy. However, the combination of cisplatin with other phytochemicals has been identified as a promising alternative to subjugate cisplatin resistance. Phytochemicals are promising chemo-preventive and chemotherapeutic agents as they possess antioxidant, anti-inflammatory, and anti-proliferative potential against many cancers, including cervical cancer. Furthermore, the ability of the phytochemicals to modulate cellular signaling pathways through up and down regulation of various proteins has been claimed for their therapeutic potential. Phytochemicals also display a wide range of biological functions, including cell cycle arrest, apoptosis induction, inhibition of invasion, and migration in cervical cancer cells. Numerous studies have revealed the critical role of different signaling proteins and their signaling pathways in the pathogenesis of cervical cancer. Here, we review the ability of several dietary phytochemicals to alter carcinogenesis by modulating various molecular targets.

Recent Advances in the Development of Toll-like Receptor Agonist-Based Vaccine Adjuvants for Infectious Diseases

Vaccines are powerful tools for controlling microbial infections and preventing epidemic diseases. Efficient inactive, subunit, or viral-like particle vaccines usually rely on a safe and potent adjuvant to boost the immune response to the antigen. After a slow start, over the last decade there has been increased developments on adjuvants for human vaccines. The development of adjuvants has paralleled our increased understanding of the molecular mechanisms for the pattern recognition receptor (PRR)-mediated activation of immune responses. Toll-like receptors (TLRs) are a group of PRRs that recognize microbial pathogens to initiate a host’s response to infection. Activation of TLRs triggers potent and immediate innate immune responses, which leads to subsequent adaptive immune responses. Therefore, these TLRs are ideal targets for the development of effective adjuvants. To date, TLR agonists such as monophosphoryl lipid A (MPL) and CpG-1018 have been formulated in licensed vaccines for their adjuvant activity, and other TLR agonists are being developed for this purpose. The COVID-19 pandemic has also accelerated clinical research of vaccines containing TLR agonist-based adjuvants. In this paper, we reviewed the agonists for TLR activation and the molecular mechanisms associated with the adjuvants’ effects on TLR activation, emphasizing recent advances in the development of TLR agonist-based vaccine adjuvants for infectious diseases.

Human papillomavirus vaccine efficacy against invasive, HPV-positive cancers: population-based follow-up of a cluster-randomised trial

BACKGROUND

Human papillomavirus (HPV) vaccination protects against HPV, a necessary risk factor for cervical cancer. We now report results from population-based follow-up of randomised cohorts that vaccination provides HPV-type-specific protection against invasive cancer.

METHODS

Individually and/or cluster randomised cohorts of HPV-vaccinated and non-vaccinated women were enrolled in 2002-2005. HPV vaccine cohorts comprised originally 16-17 year-old HPV 16/18-vaccinated PATRICIA (NCT00122681) and 012 trial (NCT00169494) participants (2465) and HPV6/11/16/18-vaccinated FUTURE II (NCT00092534) participants (866). Altogether, 3341 vaccines were followed by the Finnish Cancer Registry in the same way as 16 526 non-HPV-vaccinated controls. The control cohort stemmed from 15 665 originally 18-19 years-old women enrolled in 2003 (6499) or 2005 (9166) and 861 placebo recipients of the FUTURE II trial. The follow-up started 6 months after the clinical trials in 2007 and 2009 and ended in 2019. It was age aligned for the cohorts.

FINDINGS

During a follow-up time of up to 11 years, we identified 17 HPV-positive invasive cancer cases (14 cervical cancers, 1 vaginal cancer, 1 vulvar cancer and 1 tongue cancer) in the non-HPV-vaccinated cohorts and no cases in the HPV-vaccinated cohorts. HPV typing of diagnostic tumour blocks found HPV16 in nine cervical cancer cases, HPV18, HPV33 and HPV52 each in two cases and HPV45 in one cervical cancer case. The vaginal, vulvar and tongue cancer cases were, respectively, positive for HPV16, HPV52/66 and HPV213. Intention-to-treat vaccine efficacy against all HPV-positive cancers was 100% (95% CI 2 to 100, p<0.05).

INTERPRETATION

Vaccination is effective against invasive HPV-positive cancer.

TRIAL REGISTRATION NUMBER

NCT00122681, Post-results; NCT00169494, Post-results; NCT00092534, Post-results.

Generation of potent cellular and humoral immunity against SARS-CoV-2 antigens via conjugation to a polymeric glyco-adjuvant

The SARS-CoV-2 virus has caused an unprecedented global crisis, and curtailing its spread requires an effective vaccine which elicits a diverse and robust immune response. We have previously shown that vaccines made of a polymeric glyco-adjuvant conjugated to an antigen were effective in triggering such a response in other disease models and hypothesized that the technology could be adapted to create an effective vaccine against SARS-CoV-2. The core of the vaccine platform is the copolymer p(Man-TLR7), composed of monomers with pendant mannose or a toll-like receptor 7 (TLR7) agonist. Thus, p(Man-TLR7) is designed to target relevant antigen-presenting cells (APCs) via mannose-binding receptors and then activate TLR7 upon endocytosis. The p(Man-TLR7) construct is amenable to conjugation to protein antigens such as the Spike protein of SARS-CoV-2, yielding Spike-p(Man-TLR7). Here, we demonstrate Spike-p(Man-TLR7) vaccination elicits robust antigen-specific cellular and humoral responses in mice. In adult and elderly wild-type mice, vaccination with Spike-p(Man-TLR7) generates high and long-lasting titers of anti-Spike IgGs, with neutralizing titers exceeding levels in convalescent human serum. Interestingly, adsorbing Spike-p(Man-TLR7) to the depot-forming adjuvant alum amplified the broadly neutralizing humoral responses to levels matching those in mice vaccinated with formulations based off of clinically-approved adjuvants. Additionally, we observed an increase in germinal center B cells, antigen-specific antibody secreting cells, activated T follicular helper cells, and polyfunctional Th1-cytokine producing CD4+ and CD8+ T cells. We conclude that Spike-p(Man-TLR7) is an attractive, next-generation subunit vaccine candidate, capable of inducing durable and robust antibody and T cell responses.

Effectiveness of various human papillomavirus vaccination strategies: A community randomized trial in Finland

INTRODUCTION

We conducted a community-randomized trial (NCTBLINDED) in Finland to assess gender-neutral and girls-only vaccination strategies with the AS04-adjuvanted human papillomavirus (HPV)-16/18 (AS04-HPV-16/18)vaccine.

METHODS

Girls and boys (12-15 years) were invited. We randomized 33 communities (1:1:1 ratio): Arm A: 90% of randomly selected girls and boys received AS04-HPV-16/18 vaccine and 10% received hepatitis B vaccine (HBV); Arm B: 90% of randomly selected girls received AS04-HPV-16/18 vaccine, 10% of girls received HBV, and all boys received HBV; Arm C: all participants received HBV. Effectiveness measurements against prevalence of HPV-16/18 cervical infection were estimated in girls at 18.5 years. The main measures were: (1) overall effectiveness comparing Arms A or B, regardless of vaccination status, vs Arm C; (2) total effectiveness comparing AS04-HPV-16/18 vaccinated girls in pooled Arms A/B vs Arm C; (3) indirect effectiveness (herd effect) comparing girls receiving HBV or unvaccinated in Arm A vs Arm C. Co-primary objectives were overall effectiveness following gender-neutral or girls-only vaccination.

RESULTS

Of 80,272 adolescents invited, 34,412 were enrolled. Overall effectiveness was 23.8% (95% confidence interval: -19.0, 51.1; P = 0.232) with gender-neutral vaccination. Following girls-only vaccination, overall effectiveness was 49.6% (20.1, 68.2; P = 0.004). Total effectiveness was over 90% regardless of vaccination strategy. No herd effect was found. Immunogenicity of the AS04-HPV-16/18 vaccine was high in both sexes.

CONCLUSIONS

This study illustrates the difficulty in conducting community randomized trials. It is not plausible that vaccinating boys would reduce overall effectiveness, and the apparent lack of herd effect was unexpected given findings from other studies. This analysis was likely confounded by several factors but confirms the vaccine's high total effectiveness as in clinical trials.

Sustainability of neutralising antibodies induced by bivalent or quadrivalent HPV vaccines and correlation with efficacy: a combined follow-up analysis of data from two randomised, double-blind, multicentre, phase 3 trials

BACKGROUND

Quadrivalent and bivalent vaccines against oncogenic human papillomavirus (HPV) are used worldwide with different reported overall efficacies against HPV infections. Although protective concentrations of vaccine-induced antibodies are still not formally defined, we evaluated the sustainability of neutralising antibodies in vaccine trial participants 2-12 years after vaccination and the correlation with reported vaccine efficacy.

METHODS

We did a follow-up analysis of data from the Finnish cohorts of two international, randomised, double-blind, phase 3 trials of HPV vaccines, PATRICIA (bivalent, HPV16 and 18) and FUTURE II (quadrivalent, HPV6, 11, 16, and 18). In 2002 and 2004-05, respectively, Finnish girls aged 16-17 years participated in one of these two trials and consented to health registry follow-up with the Finnish Cancer Registry. The cohorts were also linked with the Finnish Maternity Cohort (FMC) that collects first-trimester serum samples from nearly all pregnant Finnish women, resulting in 2046 post-vaccination serum samples obtained during up to 12 years of follow-up. We obtained serum samples from the FMC-based follow-up of the FUTURE II trial (from the quadrivalent vaccine recipients) and the PATRICIA trial (from corresponding bivalent vaccine recipients who were aligned by follow-up time, and matched by the number of pregnancies). We assessed neutralising antibody concentrations (type-specific seroprevalence) to HPV6, 16, and 18, and cross-neutralising antibody responses to non-vaccine HPV types 31, 33, 45, 52, and 58 from 2 to 12 years after vaccination.

FINDINGS

Up to Dec 31, 2016, we obtained and analysed 577 serum samples from the quadrivalent vaccine recipients and 568 from the bivalent vaccine recipients. In 681 first-pregnancy serum samples, neutralising antibodies to HPV6, 16, and 18 were generally found up to 12 years after vaccination. However, 51 (15%) of 339 quadrivalent vaccine recipients had no detectable HPV18 neutralising antibodies 2-12 years after vaccination, whereas all 342 corresponding bivalent vaccine recipients had HPV18 neutralising antibodies.. In seropositive quadrivalent vaccine recipients, HPV16 geometric mean titres (GMT) halved by years 5-7 (GMT 3679, 95% CI 2377 to 4708) compared with years 2-4 (6642, 2371 to 13 717). Between 5 and 12 years after vaccination, GMT of neutralising antibodies to HPV16 and 18 were 5·7 times and 12·4 times higher, respectively, in seropositive bivalent vaccine recipients than in the quadrivalent vaccine recipients. Cross-neutralising antibodies to HPV31, 33, 45, 52, and 58 were more prevalent in the bivalent vaccine recipients but, when measurable, sustainable up to 12 years after vaccination with similar GMTs in both vaccine cohorts. Seroprevalence for HPV16, 31, 33, 52, and 58 significantly correlated with vaccine efficacy against persistent HPV infections in the bivalent vaccine recipients only (r_s=0·90, 95% CI 0·09 to 0·99, p=0·037, compared with r_s=0·62, 95% CI -0·58 to 0·97, p=0·27 for the quadrivalent vaccine recipients). Correlation of protection with prevalence of neutralising or cross-neutralising HPV antibodies was not significant in the quadrivalent vaccine recipients.

INTERPRETATION

The observed significant differences in the immunogenicity of the two vaccines are in line with the differences in their cross-protective efficacy. Protective HPV vaccine-induced antibody titres can be detected up to 12 years after vaccination.

FUNDING

Academy of Finland and Finnish Cancer Foundation.

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.

Efficacy of the AS04-adjuvanted HPV-16/18 vaccine in young Chinese women with oncogenic HPV infection at baseline: post-hoc analysis of a randomized controlled trial

Human papillomavirus (HPV) vaccines are efficacious against HPV infections and associated lesions in women HPV-naïve at vaccination. However, vaccine efficacy (VE) against oncogenic, high-risk HPV (HR-HPV) types in women infected with any other HR-HPV type at first vaccination (baseline) remains unclear. This post-hoc analysis of a phase II/III study (NCT00779766) evaluated AS04-adjuvanted HPV-16/18 (AS04-HPV-16/18) VE against HR-HPV type infection in 871 Chinese women aged 18–25 years over a 72-month follow-up period. Study participants were DNA-negative at baseline to HR-HPV type(s) considered for VE and DNA-positive to any other HR-HPV type. Initial serostatus was not considered. Baseline DNA prevalence was 14.6% for any HR-HPV type and 10.6% excluding HPV-16/18. In the total vaccinated cohort for efficacy, VE against 6-month and 12-month HPV-16/18 persistent infections (PIs) in women DNA-negative to HPV-16/18 but DNA-positive to any other HR-HPV type at baseline was 100.0% (95% Confidence Interval [CI]: 79.8–100.0) and 100.0% (95%CI: 47.2–100.0), respectively. VE against HPV-16/18 incident infections in women DNA-positive to one vaccine type but DNA-negative to the other one at baseline was 66.8% (95%CI: −18.9–92.5). VE against HPV-31/33/45 incident infections, in women DNA-positive to HPV-16/18 and DNA-negative to the considered HPV type at baseline was 71.0% (95%CI: 27.3–89.8). No HPV-16/18 PIs were observed in vaccinated women with non-vaccine HPV A7/A9 species cervical infection at baseline. These findings indicated that women with existing HR-HPV infection at vaccination might still benefit from the AS04-HPV-16/18 vaccine. However, this potential benefit needs further demonstration in the future.

Systematic literature review of cross-protective effect of HPV vaccines based on data from randomized clinical trials and real-world evidence

BACKGROUND

The extent of cross-protection provided by currently licensed bivalent and quadrivalent HPV vaccines versus direct protection against HPV 31-, 33-, 45-, 52-, and 58-related disease is debated. A systematic literature review was conducted to establish the duration and magnitude of cross-protection in interventional and observational studies.

METHODS

PubMed and Embase databases were searched to identify randomized controlled trials (RCT) and observational studies published between 2008 and 2019 reporting on efficacy and effectiveness of HPV vaccines in women against non-vaccine types 31, 33, 45, 52, 58, and 6 and 11 (non-bivalent types). Key outcomes of interest were vaccine efficacy against 6- and 12-month persistent infection or genital lesions, and type-specific genital HPV prevalence or incidence. RCT data were analyzed for the according-to-protocol (bivalent vaccine) or negative-for-14-HPV-types (quadrivalent vaccine) efficacy cohorts.

RESULTS

Data from 23 RCTs and 33 observational studies evaluating cross-protection were extracted. RCTs assessed cross-protection in post-hoc analyses of small size subgroups. Among fully vaccinated, baseline HPV-naïve women, the bivalent vaccine showed statistically significant cross-protective efficacy, although with wide confidence intervals, against 6-month and 12-month persistent cervical infections and CIN2+ only consistently for HPV 31 and 45, with the highest effect observed for HPV 31 (range 64.6% [95% CI: 27.6 to 83.9] to 79.1% [97.7% CI: 27.6 to 95.9] for 6-month persistent infection; maximal follow-up 4.7 years). No cross-protection was shown in extended follow-up. The quadrivalent vaccine efficacy reached statistical significance for HPV 31 (46.2% [15.3-66.4]; follow-up: 3.6 years). Similarly, observational studies found consistently significant effectiveness only against HPV 31 and 45 with both vaccines.

CONCLUSIONS

RCTs and observational studies show that cross-protection is inconsistent across non-vaccine HPV types and is largely driven by HPV 31 and 45. Furthermore, existing data suggest that it wanes over time; its long-term durability has not been established.

Systematic literature review of neutralizing antibody immune responses to non-vaccine targeted high-risk HPV types induced by the bivalent and the quadrivalent vaccines

INTRODUCTION

Studies on the cross-protective effect of HPV bivalent and quadrivalent vaccines demonstrated inconsistent findings against additional HPV types covered by the nonavalent vaccine. The objective of this study was to conduct a systematic literature review to assess the consistency and durability of the cross-protective neutralizing antibody immune responses of the currently licensed bivalent and quadrivalent vaccines to non-vaccine HPV types targeted by the nonavalent vaccine (HPV 6, 11, 31, 33, 45, 52, and 58).

METHODS

PubMed and EMBASE databases were searched from 2008 to 2019 to identify studies reporting antibody/immune response after vaccination with either the bivalent, quadrivalent, or nonavalent vaccine. Key outcomes were seroconversion, seropositivity or geometric mean titers against HPV types 6, 11, 31, 33, 45, 52, and 58.

RESULTS

Eighteen publications met inclusion criteria, reporting on 14 interventional and five observational studies. Across all studies, immune responses to non-vaccine high-risk HPV types after bivalent vaccination were higher than baseline or quadrivalent vaccine. Nonavalent vaccine elicited near total seroconversion to HPV types 31, 33, 45, 52, and 58, with seropositivity remaining near 100% up to 24 months post-dose 1. In contrast, bivalent and quadrivalent vaccination resulted in lower seroconversion levels for non-vaccine types, which waned over time.

CONCLUSIONS

The cross-protection antibody/immune response among participants having received all three doses of bivalent or quadrivalent vaccine is not comparable to the specific response elicited by HPV vaccine types. Even in cases where a statistically significant cross-reactive immunological response is reported, long-term data on the duration of the response beyond two years are very limited. Further, the lack of a standard for assays limits comparability of results between studies.