Efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine in Chinese women aged 18-25 years: event-triggered analysis of a randomized controlled trial

Meeting report: Considerations for trial design and endpoints in licensing therapeutic HPV16/18 vaccines to prevent cervical cancer

Cervical cancer is a major cause of morbidity and mortality globally with a disproportionate impact on women in low- and middle-income countries. In 2021, the World Health Organization (WHO) called for increased vaccination, screening, and treatment to eliminate cervical cancer. However, even with widespread rollout of human papillomavirus (HPV) prophylactic vaccines, millions of women who previously acquired HPV infections will remain at risk for progression to cancer for decades to come. The development and licensing of an affordable, accessible therapeutic HPV vaccine, designed to clear or control carcinogenic HPV and/or to induce regression precancer could significantly contribute to the elimination efforts, particularly benefiting those who missed out on the prophylactic vaccine. One barrier to development of such vaccines is clarity around the regulatory pathway for licensure. In Washington, D.C. on September 12-13, 2023, a meeting was convened to provide input and guidance on trial design with associated ethical and regulatory considerations. This report summarizes the discussion and conclusions from the meeting. Expert presentation topics included the current state of research, potential regulatory challenges, WHO preferred product characteristics, modeling results of impact of vaccine implementation, epidemiology and natural history of HPV infection, immune responses related to viral clearance and/or precancer regression including potential biomarkers, and ethical considerations. Panel discussions were held to explore specific trial design recommendations to support the licensure process for two vaccine indications: (1) treatment of prevalent HPV infection or (2) treatment of cervical precancers. Discussion covered inclusion/exclusion criteria, study endpoints, sample size and power, safety, study length, and additional data needed, which are reported here. Further research of HPV natural history is needed to address identified gaps in regulatory guidance, especially for therapeutic vaccines intended to treat existing HPV infections.

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.

Prospective, multi-center post-marketing surveillance cohort study to monitor the safety of the human papillomavirus-16/18 AS04-adjuvanted vaccine in Chinese girls and women aged 9 to 45 years, 2018-2020

Following the approval of Cervarix for the immunization of girls and women in China against high-risk human papillomavirus types 16 and 18, a non-interventional post-authorization safety study was performed. A multi-center prospective cohort study assessed safety following Cervarix vaccination of Chinese girls and women aged 9-45 years between 31 May 2018 and 3 December 2020. Adverse events following immunization (AEFIs), potential immune-mediated diseases (pIMDs), and pregnancy-related outcomes were collected up to 12 months from the third immunization or 24 months from the first immunization, whichever came first. Among 3,013 women who received 8,839 Cervarix doses, 167 (5.5%) reported ≥ 1 any AEFI, and 22 (0.7%) reported 40 serious AEFIs. During the 30 days after each dose, 147 women (4.9%) reported 211 medically attended AEFIs, including 3 serious AEFIs reported by 1 woman (0.03%). One woman reported a pIMD. Cervarix was inadvertently administered to 65 women (2.2%) within 60 days before conception or during pregnancy. Of these women, 34 (52.3%) gave birth to live infant(s) with no apparent congenital anomalies, and 1 (1.5%) woman gave birth to a live infant with a congenital anomaly. No serious AEFIs or pIMDs were considered to be related to the vaccination. In Chinese women aged 9-45 years, immunization with the Cervarix three-dose schedule was well tolerated. Overall, no safety concerns were identified, although rare adverse events may have been missed due to the study sample size.Clinical trial registration: NCT03438006.

Preference for human papillomavirus vaccine type and vaccination strategy among parents of school-age girls in Guangdong province, China

In China, the human papillomavirus (HPV) vaccination coverage among age-eligible girls is rather low, and parent's attitude often plays a determinant role in their girls' HPV vaccination. To accelerate HPV vaccination coverage, several cities and Guangdong province in China offered different HPV vaccine types with different reimbursement methods. In April 2022, we conducted a province-wide survey to investigate parents of children aged 9-15 in Guangdong province, and analyzed factors associated with their preference for HPV vaccine type and vaccination strategy. Of the 4,967 surveyed respondents, 2,610 (58.1%) have not yet vaccinated their children. Among these parents, 67.9% preferred to vaccinate their children with the nine-valent vaccine, while only 8.1% preferred the quadrivalent vaccine and 7.4% preferred the bivalent vaccine. More parents preferred fixed subsidies with free choices of HPV vaccine type over the domestic bivalent vaccine provided by the government (58.1% vs. 39.3%). The multinomial logistic regression showed that parents' relationship with children, educational level, household income, and vaccination status were significantly associated with parents' preference for HPV vaccine type. Parent's relationship with children, workplace, household income, vaccination status, and age of children, were significantly associated with parents' preference for HPV vaccination strategy. Our findings suggest that policymakers may consider adjusting the current vaccination strategy by offering more vaccination choices. More health education on HPV vaccine and vaccination should also be provided to parents of age-eligible girls. Future research should examine which HPV vaccination strategy is more effective in promoting HPV vaccine uptakes in China.

A feasibility assessment of real-world data capabilities for monitoring vaccine safety and effectiveness in China: Human papillomavirus vaccination in the Yinzhou district as a use case

BACKGROUND

Real-world data (RWD) are increasingly used to generate real-world evidence (RWE) of vaccine safety and effectiveness for regulatory purposes. Assessing feasibility of using RWD sources prior to implementing observational studies is recommended. As a use case, we described the process and findings of a feasibility assessment to identify reliable and relevant data sources for monitoring the safety and effectiveness of the AS04-HPV-16/18 human papillomavirus (HPV) vaccine in China.

METHODS

Iterative multi-step process: (1) targeted literature review and data source mapping; (2) expert opinion from national RWD experts; (3) survey to evaluate the identified data source operational infrastructure; and (4) continuous appraisal of published studies using the identified data source.

RESULTS

The Yinzhou Regional Health Information Platform (YRHIP) was identified as a data source of main interest, based on its large population coverage, high cervical cancer screening rates, and availability of adult electronic immunization records. Field meetings with national RWD experts confirmed its suitability for post-authorization vaccine studies. Survey results showed that exposure data and relevant safety and effectiveness endpoints were recorded and linkable at the individual level across the platform. Iterative appraisal of emerging evidence from the literature corroborated these findings.

CONCLUSIONS

This feasibility assessment indicates that the YRHIP has the capacity to capture demographic, exposure, outcome and other data required to generate RWE on HPV vaccine safety and effectiveness in China. Studies using the YRHIP to monitor the AS04-HPV-16/18 vaccine in routine use building on this feasibility assessment are ongoing.

MOnitoring human papillomavirus Vaccine effect on Infection and cErvical diseases (MOVIE): Protocol for a cohort study using electronic health records from Yinzhou, China

Cervical cancer is the fourth most common cancer in women, with a high disease burden worldwide. Human papillomavirus (HPV) vaccination reduces HPV-related infection and associated cervical lesions and cancers. Few studies have explored HPV vaccination impact in real-world settings in China. This study aims to monitor HPV vaccine uptake and its effects on HPV-related diseases, evaluating vaccine effectiveness in a real-world context and complementing clinical trial results. Electronic health records (EHRs) from 2010 to 2020 from the Yinzhou Regional Health Information Platform (YRHIP) will be queried/extracted to identify and monitor HPV vaccine uptake in females aged 9-45 years, and HPV-related screening and prevalence (i.e., cervical HPV infection, cervical intraepithelial neoplasia [CIN] grades 1-3, and cervical cancer) in a cohort of females aged 9-70 years. Cervical cancer screening guidelines and expert consultation will be used for intra-database validation, to determine the best algorithm for identifying HPV-related disease. Pre-launch (2010-2016) and post-launch (2018-2020) periods are predefined. A time trend analysis will be performed to describe the vaccination impact on disease prevalence and, if prerequisite conditions are met, vaccine effectiveness will be computed using logistic regression, adjusting for age, calendar year, history of screening and HPV infection. Cohort study design, outcomes validation, data linkage, and multi-step statistical analyses could provide valuable experience for designing other real-world studies in the future. The study outcomes can help inform policy-makers about uptake and HPV vaccination policy in girls and women in Yinzhou District, and provide insights on progress toward achieving goals set by the World Health Organization.

Safety and immunogenicity of a pichia pastoris-expressed bivalent human papillomavirus (types 16 and 18) L1 virus-like particle vaccine in healthy Chinese women aged 9-45 years: A randomized, double-blind, placebo-controlled phase 1 clinical trial

BACKGROUND

We evaluated the safety and immunogenicity of high and low doses of a novel pichia pastoris-expressed bivalent (types 16 and 18) human papillomavirus (HPV) virus-like particle vaccine.

METHODS

In this randomized, double-blind, placebo-controlled phase 1 trial, we enrolled 160 healthy females aged 9-45 years in Guangxi, China who were randomized (1:1:2) to receive either low (0.5 mL) or high (1.0 mL) dosages of bivalent HPV vaccine, or placebo (aluminum adjuvant) in a 0, 2, 6 months schedule. Adverse events and other significant conditions that occurred within 30 days after each vaccination were recorded throughout the trial. Sera were collected at days 0, 60, 180 and 210 to measure anti-HPV 16/18 neutralizing antibodies.

RESULTS

A total of 160 participants received at least one dose of the HPV vaccine and 152 completed the three dose vaccination series. Reporting rates of adverse events in placebo, low dose (0.5 mL) and high dose (1.0 mL) groups were 47.5 %, 55.0 % and 55.0 %, respectively. No serious adverse events occurred during this trial. 100 % of the participants who received three doses of the HPV vaccine produced neutralizing antibodies against HPV 16/18 vaccine. For HPV 16 and HPV 18, the geometric mean titers (GMTs) were similar between the low dose group (GMT_{HPV 16} = 10816 [95 % CI: 7824-14953]), GMT_{HPV 18} = 3966 [95 % CI: 2693-5841]) and high dose group (GMT _{HPV 16} = 14482 [95 % CI: 10848-19333], GMT _{HPV 18} = 3428 [95 % CI: 2533-4639]).

CONCLUSION

The pichia pastoris-expressed bivalent HPV vaccine was safe and immunogenic in Chinese females aged 9-45 years. The low dosage (0.5 mL) was selected for further immunogenicity and efficacy study.

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).

Efficacy of prophylactic human papillomavirus vaccines on cervical cancer among the Asian population: A meta-analysis

Objective

We conducted a meta-analysis to assess the efficacy of prophylactic human papillomavirus (HPV) vaccines against cervical cancer precursors and HPV persistent infection among Asian populations.

Methods

Randomized controlled clinical trials conducted in Asian countries were identified from three electronic databases (PubMed, EMBASE and the Cochrane Library). Publication retrieval was performed on September 1, 2022 and only those written in English were included. The data were analyzed with Cochrane Review Manager (version 5.3) and Stata/SE (15.1). Effect sizes were presented as risk ratios (RRs) and 95% confidence intervals (CIs).

Results

Ten articles were considered in the meta-analysis, without significant heterogeneity among them. The fixed-effect RRs and 95% CIs for cervical intraepithelial neoplasia grade 1 (CIN1+) and CIN2+ were 0.10 (0.05–0.21) and 0.11 (0.04–0.27), respectively. Positive effect of HPV vaccination on 6- and 12-month persistent infection were observed, with the respective pooled RRs of 0.05 (95% CI: 0.03–0.09) and 0.09 (95% CI: 0.05–0.15). HPV vaccination has a positive effect on the incidence of cytological abnormalities associated with HPV 16/18 (RR, 0.13; 95% CI (0.09–0.20)). Positive effects of HPV vaccination were also observed for HPV 16- and 18-specific immunogenicity (RR, 235.02; 95% CI (82.77–667.31) and RR, 98.24; 95% CI (50.36–191.67), respectively). Females receiving an initial vaccination showed significant decreased incidences of cervical intraepithelial neoplasia, HPV persistent infection and cytological abnormalities and a significantly higher antibody positive conversion rate compared with non-vaccination counterparts.

Conclusion

Prophylactic HPV vaccines are highly efficacious in preventing cervical cancer in Asian females. The government should accelerate the processes of vaccine introduction and vaccination implementation by prioritizing them in public health policies, which should be helpful to enhance Asian females’ awareness of receiving HPV vaccination volitionally.

Efficacy, safety, and immunogenicity of an Escherichia coli-produced Human Papillomavirus (16 and 18) L1 virus-like-particle vaccine: end-of-study analysis of a phase 3, double-blind, randomised, controlled trial

BACKGROUND

This Escherichia coli-produced bivalent HPV 16 and 18 vaccine was well tolerated and effective against HPV 16 and 18 associated high-grade genital lesions and persistent infection in interim analysis of this phase 3 trial. We now report data on long-term efficacy and safety after 66 months of follow-up.

METHODS

This phase 3, double-blind, randomised, controlled trial was done in five study sites in China. Eligible participants were women aged 18-45 years, with intact cervix and 1-4 lifetime sexual partners. Women who were pregnant or breastfeeding, had chronic disease or immunodeficiency, or had HPV vaccination history were excluded. Women were stratified by age (18-26 and 27-45 years) and randomly (1:1) allocated by software (block randomisation with 12 codes to a block) to receive three doses of the E coli-produced HPV 16 and 18 vaccine or hepatitis E vaccine (control) and followed-up for 66 months. The primary outcomes were high-grade genital lesions and persistent infection (longer than 6 months) associated with HPV 16 or 18 in the per-protocol susceptible population. This trial was registered with ClinicalTrials.gov, NCT01735006.

FINDINGS

Between Nov 22, 2012, and April 1, 2013, 8827 women were assessed for eligibility. 1455 women were excluded, and 7372 women were enrolled and randomly assigned to receive the HPV vaccine (n=3689) or control (n=3683). Vaccine efficacy was 100·0% (95% CI 67·2-100·0) against high-grade genital lesions (0 [0%] of 3310 participants in the vaccine group and 13 [0·4%] of 3302 participants in the control group) and 97·3% (89·9-99·7) against persistent infection (2 [0·1%] of 3262 participants in the vaccine group and 73 [2·2%] of 3271 participants in the control group) in the per-protocol population. Serious adverse events occurred at a similar rate between vaccine (267 [7·2%] of 3691 participants) and control groups (290 [7·9%] of 3681); none were considered related to vaccination.

INTERPRETATION

The E coli-produced HPV 16 and 18 vaccine was well tolerated and highly efficacious against HPV 16 and 18 associated high-grade genital lesions and persistent infection and would supplement the global HPV vaccine availability and accessibility for cervical cancer prevention.

FUNDING

National Natural Science Foundation of China, National Key R&D Program of China, Fujian Provincial Project, Fundamental Funds for the Central Universities, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, and Xiamen Innovax.

Rationale and Clinical Research Progress on PD-1/PD-L1-Based Immunotherapy for Metastatic Triple-Negative Breast Cancer

Metastatic triple-negative breast cancer (mTNBC), a highly aggressive and malignant tumor, currently lacks an effective treatment. There has been some progress in the treatment of mTNBC with programmed death receptor-1/programmed death ligand-1 (PD-1/PD-L1) immunotherapy in recent years. The combination of PD-1/PD-L1 inhibitors with other therapies is a noteworthy treatment strategy. Immunotherapy in combination with chemotherapy or small-molecule inhibitors still faces many challenges. Additionally, there are some new immunotherapy targets in development. We aimed to further evaluate the effectiveness and usefulness of immunotherapy for treating mTNBC and to propose new immunotherapy strategies. This review explains the rationale and results of existing clinical trials evaluating PD-1/PD-L1 inhibitors alone or in combination for the treatment of mTNBC. For patients with aggressive tumors and poor health, PD-1/PD-L1 inhibitors, either alone or in combination with other modalities, have proven to be effective. However, more research is needed to explore more effective immunotherapy regimens that will lead to new breakthroughs in the treatment of mTNBC.

Elimination of Cervical Cancer: Challenges Promoting the HPV Vaccine in China

Objective

Cervical cancers present major threats to women's health in China. Eliminating cervical cancer in China is a huge challenge, with application of the HPV vaccine, which is an important part.

Methods

There are currently four HPV vaccines available in China: E-coli bv-HPV (Wantai, China), bv-HPV, qv-HPV (GSK, UK), and 9v-HPV (MSD, USA). To observe the immunogenicity, efficacy, and safety of these four vaccines in China, we formed the "Chinese Expert Consensus on the Clinical Application of HPV Vaccine."

Results

At 7 months after vaccination, all vaccinated subjects had the same immunogenic response to either HPV16 or HPV18, ranging from 96 to 100%, and antibody production in girls aged 9-14 years was 2-3 times higher than that in adult women. Efficacy of the four vaccines against CIN2 + ranged from 87.3%  to 100%, with prevention of HPV-associated infection reaching 96% ~ 97% at 12 months. Clinical trials showed bv-HPV and qv-HPV vaccine were also safe in women aged 18-45 years. Clinical trials of the 9v-HPV vaccine are underway. HPV vaccination is currently voluntary and self-paid in China. The "Chinese Expert Consensus on the Clinical Application of HPV Vaccine" will work to promote the application of HPV vaccine in China.

Conclusions

In clinical studies, the available HPV vaccines showed excellent efficacy, safety, and immunogenicity in Chinese women. We will continue strengthening screening and encouraging HPV vaccination.

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.

Long‐term persistence of immune response to the AS04‐adjuvanted HPV‐16/18 vaccine in Chinese girls aged 9‐17 years: Results from an 8‐9‐year follow‐up phase III open‐label study

Aim

In 9‐17‐year‐old Chinese girls, the AS04‐adjuvanted HPV‐16/18 vaccine (AS04‐HPV‐16/18) given as three‐dose schedule induced high antibody levels, which were noninferior 1 month after the third dose to those observed in 18‐25‐year‐old Chinese women in a large efficacy study. We assessed the persistence of antibodies 8‐9 years after vaccination in the same subjects.

Methods

This follow‐up phase III, open‐label study (NCT03355820) included subjects who had received three doses of AS04‐HPV‐16/18 in the initial trial (NCT00996125). Serum antibody concentrations were assessed by ELISA and compared to antibody persistence observed in 18‐25‐year‐old Chinese women 6 years after first vaccination in the efficacy study (NCT00779766).

Results

Out of the 227 enrolled subjects, 223 were included in the per‐protocol immunogenicity analysis. Mean interval from first AS04‐HPV‐16/18 dose to blood sampling was 101.4 months (8.5 years). For antibodies against HPV‐16 and ‐18, 8.5 years after first vaccine dose all subjects remained seropositive and antibody. Geometric mean concentrations (GMCs) were 1236.3 (95% confidence interval [CI]: 1121.8; 1362.4) and 535.6 (95% CI: 478.6; 599.4) ELISA Units/mL, respectively. These seropositivity rates and antibody GMCs were higher than those observed 6 years after first vaccination of 18‐25‐year‐old women.

Conclusion

Sustained anti‐HPV‐16 and ‐18 immune responses were observed 8‐9 years after AS04‐HPV‐16/18 vaccination of 9‐17 year‐old Chinese girls that were higher than the ones observed 6 years after first vaccination in Chinese adult women in whom AS04‐HPV‐16/18 efficacy against cervical intraepithelial neoplasia of grade ≥2 was demonstrated.

Impact of HPV-16/18 AS04-adjuvanted vaccine on preventing subsequent infection and disease after excision treatment: post-hoc analysis from a randomized controlled trial

BACKGROUND

It is widely acknowledged that HPV prophylactic vaccine could prevent new infections and their associated lesions among women who are predominantly HPV-naive at vaccination. Yet there still remains uncertainty about whether HPV vaccination could benefit to individuals who have undergone surgery for cervical disease.

METHODS

This post-hoc analysis intends to focus on intent-to-treat participants who underwent excision treatment at baseline and the follow-up period in a phase II/III, double-blind, randomized trial ( ClinicalTrials.gov , number NCT00779766 ) conducted in Jiangsu province, China. We evaluate the impact of HPV vaccination on preventing women from subsequent infection and cervical lesions (LSIL+ and CIN2+) after excision treatment.

RESULTS

One hundred sixty-eight (vaccine, n = 87; placebo, n = 81) performed excisional treatment in this clinical trial. We observed a significant effect of vaccination on acquiring 14 high-risk HPV (HR-HPV) infection after treatment (vaccine efficacy: 27.0%; 95% CI 4.9, 44.0%). The vaccine efficacy against new infections after treatment for 14 HR-HPV infection was estimated as 32.0% (95%CI 1.8, 52.8%), and was 41.2% (95%CI -162.7, 86.8%) for HPV16/18 infection. The accumulative clearance rates of the vaccine group and placebo group were 88.9 and 81.6% for HPV16/18 infection (P = 0.345), 63.4, 48.7% for 14 HR-HPV infection (P = 0.062), respectively. No significant difference was observed on the persistent rate of HPV16/18, 14 HR-HPV infection and occurrence rate of LSIL+ between the two groups.

CONCLUSIONS

No significant evidence from this study showed that HPV-16/18 AS04-adjuvanted vaccine could lead to viral faster clearance or have any effect on the rates of persistent infection among women who had excision treatment. However, the vaccine may still benefit post-treatment women with "primary prophylactic" effect. Further research is required in clarifying the effect of using the prophylactic HPV vaccine as therapeutic agents.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00779766 . Date and status of trial registration: October 24, 2008. Completed; Has Results.

Measuring vaccine effectiveness against persistent HPV infections: a comparison of different statistical approaches

BACKGROUND

Persistent high-risk human papillomavirus (HPV) infection is endorsed by the World Health Organization as an intermediate endpoint for evaluating HPV vaccine effectiveness/efficacy. There are different approaches to estimate the vaccine effectiveness/efficacy against persistent HPV infections.

METHODS

We performed a systematic literature search in Pubmed to identify statistical approaches that have been used to estimate the vaccine effectiveness/efficacy against persistent HPV infections. We applied these methods to data of a longitudinal observational study to assess their performance and compare the obtained vaccine effectiveness (VE) estimates.

RESULTS

Our literature search identified four approaches: the conditional exact test for comparing two independent Poisson rates using a binomial distribution, Generalized Estimating Equations for Poisson regression, Prentice Williams and Peterson total time (PWP-TT) and Cox proportional hazards regression. These approaches differ regarding underlying assumptions and provide different effect measures. However, they provided similar effectiveness estimates against HPV16/18 and HPV31/33/45 persistent infections in a cohort of young women eligible for routine HPV vaccination (range VE 93.7-95.1% and 60.4-67.7%, respectively) and seemed robust to violations of underlying assumptions.

CONCLUSIONS

As the rate of subsequent infections increased in our observational cohort, we recommend PWP-TT as the optimal approach to estimate the vaccine effectiveness against persistent HPV infections in young women. Confirmation of our findings should be undertaken by applying these methods after longer follow-up in our study, as well as in different populations.

Cost-effectiveness of 2-dose human papillomavirus vaccination for 12-year-old girls in Zhejiang Province: implications for China's expanded program on immunization

BACKGROUND

The high cost and insufficient supply of HPV vaccines have substantially slowed their implementation in lower-income countries. This study aimed to assess the incremental cost-effectiveness of two doses of human papillomavirus (HPV) vaccination (bivalent 16/18 vaccine; 2vHPV) compared to a no-vaccination scenario and a three-dose scenario in one province in China.

METHODS

A static Markov model was used to model a lifetime cohort of 100,000 girls aged 12 years at the start of vaccination. A two-dose vaccination schedule was assumed to be non-inferior to a three-dose schedule in terms of vaccine efficacy, and both vaccination schemes were assumed to provide lifelong protection. Incremental costs, health effects and incremental cost-effectiveness ratios were used to measure the outcomes when comparing the different strategies.

RESULTS

Compared to no vaccination, the incremental cost-effectiveness ratio (Chinese yuan per quality-adjusted life year) of the two-dose vaccination strategy is 12,472, and the 2-dose strategy is calculated to be cost saving relative to the 3-dose vaccination strategy.

CONCLUSIONS

Introducing the 2vHPV vaccine would be highly cost effective at a per-dose vaccine price of CNY 500, which has implications for cervical cancer control in China and other resource-limited countries.

Will HPV vaccination prevent cervical cancer?

We conducted a critical appraisal of published Phase 2 and 3 efficacy trials in relation to the prevention of cervical cancer in women. Our analysis shows the trials themselves generated significant uncertainties undermining claims of efficacy in these data. There were 12 randomised control trials (RCTs) of Cervarix and Gardasil. The trial populations did not reflect vaccination target groups due to differences in age and restrictive trial inclusion criteria. The use of composite and distant surrogate outcomes makes it impossible to determine effects on clinically significant outcomes. It is still uncertain whether human papillomavirus (HPV) vaccination prevents cervical cancer as trials were not designed to detect this outcome, which takes decades to develop. Although there is evidence that vaccination prevents cervical intraepithelial neoplasia grade 1 (CIN1) this is not a clinically important outcome (no treatment is given). Trials used composite surrogate outcomes which included CIN1. High efficacy against CIN1+ (CIN1, 2, 3 and adenocarcinoma in situ (AIS)) does not necessarily mean high efficacy against CIN3+ (CIN3 and AIS), which occurs much less frequently. There are too few data to clearly conclude that HPV vaccine prevents CIN3+. CIN in general is likely to have been overdiagnosed in the trials because cervical cytology was conducted at intervals of 6-12 months rather than at the normal screening interval of 36 months. This means that the trials may have overestimated the efficacy of the vaccine as some of the lesions would have regressed spontaneously. Many trials diagnosed persistent infection on the basis of frequent testing at short intervals, i.e. less than six months. There is uncertainty as to whether detected infections would clear or persist and lead to cervical changes.

Prevalence and Incidence of Human Papillomavirus (HPV) Infection Before and After Pregnancy: Pooled Analysis of the Control Arms of Efficacy Trials of HPV-16/18 AS04-Adjuvanted Vaccine

Objective

Data on human papillomavirus (HPV) prevalence around pregnancy were inconsistent. We assessed HPV prevalence before and after pregnancy, HPV incidence after pregnancy, and risk factors for HPV infection.

Method

Data from 15 754 women in control arms of 5 AS04-HPV-16/18 vaccine efficacy trials were analyzed, including 3001 women with at least 1 pregnancy. Results of HPV deoxyribonucleic acid testing on cervical samples were available. We analyzed risk factors, including age, region, pregnancy and its outcomes, duration from pregnancy resolution to collection of first postresolution cervical sample, previous HPV infection, cigarette smoking, and number of sexual partners with Cox regression.

Results

Prevalence of high-risk oncogenic (hr)-HPV types was similar before and after pregnancy (20.8% vs 19.8%). Incidence of hr-HPV was 40.1 per 1000 person-years (95% confidence interval [CI], 23.4–64.2) at 0–3 months, 266.7 (95% CI, 217.4–323.7) at 3–6 months, and 95.7 (95% CI, 83.9–108.7) at >6 months after pregnancy. Risk factors associated with HPV infection after pregnancy are previous HPV infection, elective abortion, and younger age at pregnancy resolution.

Conclusions

Pregnancy could not be confirmed as a risk factor for HPV infection in this population despite an increased incidence detected 3–6 months after pregnancy resolution. Most women remained HPV negative after pregnancy.

Clinical Trial Registration

NCT001226810 (HPV-008 trial), NCT00294047 (HPV-015 trial), NCT00316693 and NCT00929526 (HPV-032/063 trials), and NCT00779766 (HPV-039 trial).

Lot-to-lot consistency study of an Escherichia coli-produced bivalent human papillomavirus vaccine in adult women: a randomized trial

An Escherichia. coli-produced HPV-16/18 bivalent vaccine has been proved to be well-tolerated and highly efficacious against diseases associated with vaccine HPV types. As a part of the multi-center, randomized, double-blind phase III clinical trial, this lot-to-lot consistency study aimed to assess the safety and immunogenicity consistency of this novel HPV vaccine, which is also one of the objectives of the phase III trial. A total of 3689 healthy women aged 18-45 years were enrolled and randomly assigned 1:1:1 to three lots of the HPV vaccine groups. The primary outcomes were the IgG antibody level at 1 month after the last dose (month 7). In the immunogenicity per-protocol set (PPS), almost all of the participants seroconverted at month 7 and remained seropositive at month 42. For each paired comparison of the three lot groups, the two-sides of 90% CIs of GMC ratios for both IgG and neutralizing antibodies for HPV-16 and HPV-18 at month 7 were within the equivalence interval [0.5, 2]. Lot consistency was also demonstrated at month 42. The majority of recorded solicited reactions were mild or moderate. The incidences of solicited reactions of Lot 2 and Lot 3 were slightly higher than Lot 1. However, the incidences of solicited reactions of ≥ grade 3 and solicited reactions by symptoms were all similar among the three lot groups. None of the SAEs was considered related to vaccination by the investigator. In conclusion, this study demonstrates lot-to-lot consistency of the 3 consecutive lots of the E. coli-produced HPV-16/18 bivalent vaccine.

Comparison of different human papillomavirus (HPV) vaccine types and dose schedules for prevention of HPV-related disease in females and males

BACKGROUND

Uptake of human papillomavirus (HPV) vaccine remains low in many countries, although the bivalent and quadrivalent HPV vaccines given as a three-dose schedule are effective in the prevention of precancerous lesions of the cervix in women. Simpler immunisation schedules, such as those with fewer doses, might reduce barriers to vaccination, as may programmes that include males.

OBJECTIVES

To evaluate the efficacy, immunogenicity, and harms of different dose schedules and different types of HPV vaccines in females and males.

SEARCH METHODS

We conducted electronic searches on 27 September 2018 in Ovid MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library), and Ovid Embase. We also searched the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov (both 27 September 2018), vaccine manufacturer websites, and checked reference lists from an index of HPV studies and other relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with no language restriction. We considered studies if they enrolled HIV-negative males or females aged 9 to 26 years, or HIV-positive males or females of any age.

DATA COLLECTION AND ANALYSIS

We used methods recommended by Cochrane. We use the term 'control' to refer to comparator products containing an adjuvant or active vaccine and 'placebo' to refer to products that contain no adjuvant or active vaccine. Most primary outcomes in this review were clinical outcomes. However, for comparisons comparing dose schedules, the included RCTs were designed to measure antibody responses (i.e. immunogenicity) as the primary outcome, rather than clinical outcomes, since it is unethical to collect cervical samples from girls under 16 years of age. We analysed immunogenicity outcomes (i.e. geometric mean titres) with ratios of means, clinical outcomes (e.g. cancer and intraepithelial neoplasia) with risk ratios or rate ratios and, for serious adverse events and deaths, we calculated odds ratios. We rated the certainty of evidence with GRADE.

MAIN RESULTS

We included 20 RCTs with 31,940 participants. The length of follow-up in the included studies ranged from seven months to five years. Two doses versus three doses of HPV vaccine in 9- to 15-year-old females Antibody responses after two-dose and three-dose HPV vaccine schedules were similar after up to five years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected clinical outcome data. Evidence about serious adverse events in studies comparing dose schedules was of very low-certainty owing to imprecision and indirectness (three doses 35/1159; two doses 36/1158; 4 RCTs). One death was reported in the three-dose group (1/898) and none in the two-dose group (0/899) (low-certainty evidence). Interval between doses of HPV vaccine in 9- to 14-year-old females and males Antibody responses were stronger with a longer interval (6 or 12 months) between the first two doses of HPV vaccine than a shorter interval (2 or 6 months) at up to three years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected data about clinical outcomes. Evidence about serious adverse events in studies comparing intervals was of very low-certainty, owing to imprecision and indirectness. No deaths were reported in any of the studies (0/1898, 3 RCTs, low-certainty evidence). HPV vaccination of 10- to 26-year-old males In one RCT there was moderate-certainty evidence that quadrivalent HPV vaccine, compared with control, reduced the incidence of external genital lesions (control 36 per 3081 person-years; quadrivalent 6 per 3173 person-years; rate ratio 0.16, 95% CI 0.07 to 0.38; 6254 person-years) and anogenital warts (control 28 per 2814 person-years; quadrivalent 3 per 2831 person-years; rate ratio 0.11, 95% CI 0.03 to 0.38; 5645 person-years). The quadrivalent vaccine resulted in more injection-site adverse events, such as pain or redness, than control (537 versus 601 per 1000; risk ratio (RR) 1.12, 95% CI 1.06 to 1.18, 3895 participants, high-certainty evidence). There was very low-certainty evidence from two RCTs about serious adverse events with quadrivalent vaccine (control 12/2588; quadrivalent 8/2574), and about deaths (control 11/2591; quadrivalent 3/2582), owing to imprecision and indirectness. Nonavalent versus quadrivalent vaccine in 9- to 26-year-old females and males Three RCTs were included; one in females aged 9- to 15-years (n = 600), one in females aged 16- to 26-years (n = 14,215), and one in males aged 16- to 26-years (n = 500). The RCT in 16- to 26-year-old females reported clinical outcomes. There was little to no difference in the incidence of the combined outcome of high-grade cervical epithelial neoplasia, adenocarcinoma in situ, or cervical cancer between the HPV vaccines (quadrivalent 325/6882, nonavalent 326/6871; OR 1.00, 95% CI 0.85 to 1.16; 13,753 participants; high-certainty evidence). The other two RCTs did not collect data about clinical outcomes. There were slightly more local adverse events with the nonavalent vaccine (905 per 1000) than the quadrivalent vaccine (846 per 1000) (RR 1.07, 95% CI 1.05 to 1.08; 3 RCTs, 15,863 participants; high-certainty evidence). Comparative evidence about serious adverse events in the three RCTs (nonavalent 243/8234, quadrivalent 192/7629; OR 0.60, 95% CI 0.14 to 2.61) was of low certainty, owing to imprecision and indirectness. HPV vaccination for people living with HIV Seven RCTs reported on HPV vaccines in people with HIV, with two small trials that collected data about clinical outcomes. Antibody responses were higher following vaccination with either bivalent or quadrivalent HPV vaccine than with control, and these responses could be demonstrated to have been maintained for up to 24 months in children living with HIV (low-certainty evidence). The evidence about clinical outcomes and harms for HPV vaccines in people with HIV is very uncertain (low- to very low-certainty evidence), owing to imprecision and indirectness.

AUTHORS' CONCLUSIONS

The immunogenicity of two-dose and three-dose HPV vaccine schedules, measured using antibody responses in young females, is comparable. The quadrivalent vaccine probably reduces external genital lesions and anogenital warts in males compared with control. The nonavalent and quadrivalent vaccines offer similar protection against a combined outcome of cervical, vaginal, and vulval precancer lesions or cancer. In people living with HIV, both the bivalent and quadrivalent HPV vaccines result in high antibody responses. For all comparisons of alternative HPV vaccine schedules, the certainty of the body of evidence about serious adverse events reported during the study periods was low or very low, either because the number of events was low, or the evidence was indirect, or both. Post-marketing surveillance is needed to continue monitoring harms that might be associated with HPV vaccines in the population, and this evidence will be incorporated in future updates of this review. Long-term observational studies are needed to determine the effectiveness of reduced-dose schedules against HPV-related cancer endpoints, and whether adopting these schedules improves vaccine coverage rates.

HPV vaccine acceptance is high among adults in Mexico, particularly in people living with HIV

OBJECTIVE

To measure HPV vaccine acceptance in diverse Mexican adult popula-tions, taking into account HIV status.

MATERIALS AND METHODS

A total of 1 329 men and women, with and without HIV, participated in one of three intervention studies, offering HPV vaccination, carried out in the states of Morelos, Tlaxcala and Mexico City; either the bivalent (Morelos n=103, Tlaxcala n=127) or quadrivalent HPV-vaccine (Mexico City n=1 099) was offered.

RESULTS

HPV vaccine was accepted by 80.3% of participants; acceptance was higher in people living with HIV than those without (84.4 vs. 78%, p=0.004). Women had greater HPV infection knowledge (p<0.0001) than men and slightly higher (p=0.4) vaccine acceptance. The main reason for vaccine non-acceptance among HIV-positive participants was their doctor recommended they not get vaccinated.

CONCLUSIONS

Acceptance of HPV-vaccine was high in men and women regardless of HIV status. Even higher rates of acceptability may be achieved by educating healthcare providers to recommend HPV vaccine to their patients.

Efficacy, immunogenicity and safety of the AS04-HPV-16/18 vaccine in Chinese women aged 18-25 years: End-of-study results from a phase II/III, randomised, controlled trial

Background

Cervical cancer is a major public health concern in China. We report the end‐of‐study results of a phase II/III trial to assess the efficacy, immunogenicity, and safety of the AS04‐human papillomavirus (HPV)‐16/18 vaccine in Chinese women aged 18‐25 years followed for up to 72 months after first vaccination. Results of approximately 57 months following first vaccination have been previously reported.

Methods

Healthy 18‐25‐year‐old women (N = 6051) were randomized (1:1) to receive three doses of AS04‐HPV‐16/18 vaccine or Al(OH)₃ (control) at Months 0‐1‐6. Vaccine efficacy against HPV‐16/18 infection and cervical intraepithelial neoplasia (CIN), cross‐protective vaccine efficacy against infections and lesions associated with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. Efficacy was assessed in the according‐to‐protocol efficacy (ATP‐E) cohort (vaccine N = 2888; control N = 2892), total vaccinated cohort for efficacy (TVC‐E; vaccine N = 2987; control N = 2985) and TVC‐naïve (vaccine N = 1660; control N = 1587).

Results

In initially HPV‐16/18 seronegative/DNA‐negative women, vaccine efficacy against HPV‐16/18‐associated CIN grade 2 or worse was 87.3% (95% CI: 5.5, 99.7) in the ATP‐E, 88.7% (95% CI: 18.5, 99.7) in the TVC‐E, and 100% (95% CI: 17.9, 100) in the TVC‐naïve. Cross‐protective efficacy against incident infection with HPV‐31, HPV‐33 and HPV‐45 was 59.6% (95% CI: 39.4, 73.5), 42.7% (95% CI: 15.6, 61.6), and 54.8% (95% CI: 19.3, 75.6), respectively (ATP‐E). At Month 72, >95% of initially seronegative women who received HPV vaccine in the ATP cohort for immunogenicity (N = 664) remained seropositive for anti‐HPV‐16/18 antibodies; anti‐HPV‐16 and anti‐HPV‐18 geometric mean titers were 678.1 EU/mL (95% CI: 552.9, 831.5) and 343.7 EU/mL (95% CI: 291.9, 404.8), respectively. Serious adverse events were infrequent (1.9% vaccine group [N = 3026]; 2.7% control group [N = 3025]). Three and zero women died in the control group and the vaccine group respectively. New onset autoimmune disease was reported in two women in the vaccine group and two in the control group.

Conclusions

This is the first large‐scale randomized clinical trial of HPV vaccination in China. High and sustained vaccine efficacy against HPV‐16/18‐associated infection and cervical lesions was demonstrated up to Month 72. The vaccine had an acceptable safety profile. Combined with screening, prophylactic HPV vaccination could potentially reduce the high burden of HPV infection and cervical cancer in China.

Trial registration

NCT00779766.

Exploring the Papillomaviral Proteome to Identify Potential Candidates for a Chimeric Vaccine against Cervix Papilloma Using Immunomics and Computational Structural Vaccinology

The human papillomavirus (HPV) 58 is considered to be the second most predominant genotype in cervical cancer incidents in China. HPV type-restriction, non-targeted delivery, and the highcost of existing vaccines necessitate continuing research on the HPV vaccine. We aimed to explore the papillomaviral proteome in order to identify potential candidates for a chimeric vaccine against cervix papilloma using computational immunology and structural vaccinology approaches. Two overlapped epitope segments (23⁻36) and (29⁻42) from the N-terminal region of the HPV58 minor capsid protein L2 are selected as capable of inducing both cellular and humoral immunity. In total, 318 amino acid lengths of the vaccine construct SGD58 contain adjuvants (Flagellin and RS09), two Th epitopes, and linkers. SGD58 is a stable protein that is soluble, antigenic, and non-allergenic. Homology modeling and the structural refinement of the best models of SGD58 and TLR5 found 96.8% and 93.9% favored regions in Rampage, respectively. The docking results demonstrated a HADDOCK score of -62.5 ± 7.6, the binding energy (-30 kcal/mol) and 44 interacting amino acid residues between SGD58-TLR5 complex. The docked complex are stable in 100 ns of simulation. The coding sequences of SGD58 also show elevated gene expression in Escherichia coli with 1.0 codon adaptation index and 59.92% glycine-cysteine content. We conclude that SGD58 may prompt the creation a vaccine against cervix papilloma.

Efficacy and safety of prophylactic HPV vaccines. A Cochrane review of randomized trials

INTRODUCTION

Recently, the evidence on efficacy and safety of prophylactic HPV vaccines derived from randomized trials was published in the Cochrane database of Systematic reviews. A summary of this Cochrane review is presented below.

AREAS COVERED

Only trials involving mono-, bi-, and quadrivalent HPV vaccines were included. Trials evaluating the nonavalent vaccine were excluded since women in the control group received the quadrivalent vaccine. Main efficacy outcomes were: histologically confirmed cervical precancer lesions distinguishing those associated with vaccine HPV types and any cervical precancer. Exposure groups were: women aged: 15-26 or 24-45 years being initially negative for high-risk HPV (hrHPV) or negative for the vaccine types and women unselected by HPV status.

EXPERT COMMENTARY

All evaluated vaccines offered excellent protection against cervical intraepithelial neoplasia of grade 2 or 3 (CIN2 or CIN3) and adenocarcinoma in situ associated with HPV16/18 infection in young women who were not initially infected with hrHPV or HPV16/18. Vaccine efficacy was lower when all women regardless of HPV DNA status at enrollment were included. In young women, HPV vaccination protected also against any cervical precancer but the magnitude of protection was lower than against HPV16/18 associated cervical precancer. Vaccine efficacy was lower in mid-adult (aged 24-45 years) women. No protection against cervical precancer was found in mid-adult women unselected by HPV DNA status at enrollment. Trials were not empowered to address protection against cervical cancer. Occurrence of severe adverse events or adverse pregnancy outcomes was not significantly higher in recipients of HPV vaccines than in women included in the control arms.

Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors

BACKGROUND

Persistent infection with high-risk human papillomaviruses (hrHPV) types is causally linked with the development of cervical precancer and cancer. HPV types 16 and 18 cause approximately 70% of cervical cancers worldwide.

OBJECTIVES

To evaluate the harms and protection of prophylactic human papillomaviruses (HPV) vaccines against cervical precancer and HPV16/18 infection in adolescent girls and women.

SEARCH METHODS

We searched MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Embase (June 2017) for reports on effects from trials. We searched trial registries and company results' registers to identify unpublished data for mortality and serious adverse events.

SELECTION CRITERIA

Randomised controlled trials comparing efficacy and safety in females offered HPV vaccines with placebo (vaccine adjuvants or another control vaccine).

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology and GRADE to rate the certainty of evidence for protection against cervical precancer (cervical intraepithelial neoplasia grade 2 and above [CIN2+], CIN grade 3 and above [CIN3+], and adenocarcinoma-in-situ [AIS]), and for harms. We distinguished between the effects of vaccines by participants' baseline HPV DNA status. The outcomes were precancer associated with vaccine HPV types and precancer irrespective of HPV type. Results are presented as risks in control and vaccination groups and risk ratios (RR) with 95% confidence intervals in brackets.

MAIN RESULTS

We included 26 trials (73,428 participants). Ten trials, with follow-up of 1.3 to 8 years, addressed protection against CIN/AIS. Vaccine safety was evaluated over a period of 6 months to 7 years in 23 studies. Studies were not large enough or of sufficient duration to evaluate cervical cancer outcomes. All but one of the trials was funded by the vaccine manufacturers. We judged most included trials to be at low risk of bias. Studies involved monovalent (N = 1), bivalent (N = 18), and quadrivalent vaccines (N = 7). Most women were under 26 years of age. Three trials recruited women aged 25 and over. We summarize the effects of vaccines in participants who had at least one immunisation.Efficacy endpoints by initial HPV DNA statushrHPV negativeHPV vaccines reduce CIN2+, CIN3+, AIS associated with HPV16/18 compared with placebo in adolescent girls and women aged 15 to 26. There is high-certainty evidence that vaccines lower CIN2+ from 164 to 2/10,000 (RR 0.01 (0 to 0.05)) and CIN3+ from 70 to 0/10,000 (RR 0.01 (0.00 to 0.10). There is moderate-certainty evidence that vaccines reduce the risk of AIS from 9 to 0/10,000 (RR 0.10 (0.01 to 0.82).HPV vaccines reduce the risk of any CIN2+ from 287 to 106/10,000 (RR 0.37 (0.25 to 0.55), high certainty) and probably reduce any AIS lesions from 10 to 0/10,000 (RR 0.1 (0.01 to 0.76), moderate certainty). The size of reduction in CIN3+ with vaccines differed between bivalent and quadrivalent vaccines (bivalent: RR 0.08 (0.03 to 0.23), high certainty; quadrivalent: RR 0.54 (0.36 to 0.82), moderate certainty). Data in older women were not available for this comparison.HPV16/18 negativeIn those aged 15 to 26 years, vaccines reduce CIN2+ associated with HPV16/18 from 113 to 6 /10,000 (RR 0.05 (0.03 to 0.10). In women 24 years or older the absolute and relative reduction in the risk of these lesions is smaller (from 45 to 14/10,000, (RR 0.30 (0.11 to 0.81), moderate certainty). HPV vaccines reduce the risk of CIN3+ and AIS associated with HPV16/18 in younger women (RR 0.05 (0.02 to 0.14), high certainty and RR 0.09 (0.01 to 0.72), moderate certainty, respectively). No trials in older women have measured these outcomes.Vaccines reduce any CIN2+ from 231 to 95/10,000, (RR 0.41 (0.32 to 0.52)) in younger women. No data are reported for more severe lesions.Regardless of HPV DNA statusIn younger women HPV vaccines reduce the risk of CIN2+ associated with HPV16/18 from 341 to 157/10,000 (RR 0.46 (0.37 to 0.57), high certainty). Similar reductions in risk were observed for CIN3+ associated with HPV16/18 (high certainty). The number of women with AIS associated with HPV16/18 is reduced from 14 to 5/10,000 with HPV vaccines (high certainty).HPV vaccines reduce any CIN2+ from 559 to 391/10,000 (RR 0.70 (0.58 to 0.85, high certainty) and any AIS from 17 to 5/10,000 (RR 0.32 (0.15 to 0.67), high certainty). The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively). No data are reported in this age group for CIN3+ or AIS.Adverse effectsThe risk of serious adverse events is similar between control and HPV vaccines in women of all ages (669 versus 656/10,000, RR 0.98 (0.92 to 1.05), high certainty). Mortality was 11/10,000 in control groups compared with 14/10,000 (9 to 22) with HPV vaccine (RR 1.29 [0.85 to 1.98]; low certainty). The number of deaths was low overall but there is a higher number of deaths in older women. No pattern in the cause or timing of death has been established.Pregnancy outcomesAmong those who became pregnant during the studies, we did not find an increased risk of miscarriage (1618 versus 1424/10,000, RR 0.88 (0.68 to 1.14), high certainty) or termination (931 versus 838/10,000 RR 0.90 (0.80 to 1.02), high certainty). The effects on congenital abnormalities and stillbirths are uncertain (RR 1.22 (0.88 to 1.69), moderate certainty and (RR 1.12 (0.68 to 1.83), moderate certainty, respectively).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that HPV vaccines protect against cervical precancer in adolescent girls and young women aged 15 to 26. The effect is higher for lesions associated with HPV16/18 than for lesions irrespective of HPV type. The effect is greater in those who are negative for hrHPV or HPV16/18 DNA at enrolment than those unselected for HPV DNA status. There is moderate-certainty evidence that HPV vaccines reduce CIN2+ in older women who are HPV16/18 negative, but not when they are unselected by HPV DNA status.We did not find an increased risk of serious adverse effects. Although the number of deaths is low overall, there were more deaths among women older than 25 years who received the vaccine. The deaths reported in the studies have been judged not to be related to the vaccine. Increased risk of adverse pregnancy outcomes after HPV vaccination cannot be excluded, although the risk of miscarriage and termination are similar between trial arms. Long-term of follow-up is needed to monitor the impact on cervical cancer, occurrence of rare harms and pregnancy outcomes.

Genetic diversity and phylogenetic analysis of HPV 16 & 18 variants isolated from cervical specimens of women in Saudi Arabia

Human papillomavirus (HPV) are well known to be associated with the development of cervical cancer. HPV16 and HPV 18 are known as high-risk types and reported to be predominantly associated with cervical cancer. The prevalence and genetic diversity of HPV have been well documented globally but, in the Kingdom of Saudi Arabia, data on HPV genetic diversity are lacking. In this study, we have analyzed the genetic diversity of both HPV16 and HPV18 based on their L1 gene sequence because L1 gene is a major capsid protein gene and has been utilized to develop a prophylactic vaccine. In January 2011-2012, a total of forty samples from cervical specimens of women in Saudi Arabia were collected. The association of HPV16, HPV18 was detected by polymerase chain reaction, sequenced and submitted to GenBank. The sequences identity matrix and the phylogenetic relationship were analyzed with selected HPVs. The highest sequence identity (99.5%) for HPV16 and (99.3%) for HPV was observed with selected HPVs. The phylogenetic analysis results showed that HPVs from Saudi Arabia formed a closed cluster with African, Asian, East Asian as well as American HPVs distributed into multiple linages from various geographical locations. The results provided the valuable information about genetic diversity, but there is an urgent need to generate full genome sequence information which will provide a clearer picture of the genetic diversity and evolution of HPVs in Saudi Arabia. In conclusion, the generated data will be highly beneficial for developing molecular diagnostic tools, analyzing and correlating the epidemiological data to determine the risk of cervical cancer and finally to develop a vaccine for Saudi Arabian population.

Human papillomavirus (HPV) 18 genetic variants and cervical cancer risk in Taizhou area, China

Human papillomavirus (HPV) type 18 is predominantly associated with the development of cervical adenocarcinomas, whereas data on HPV18 genetic variability in China are limited. HPV18 genetic variants were formed phylogenetic tree, including lineages A, B, and C. We aimed to evaluate the diversity of HPV18 genetic variants by sequencing the entire E6, E7 and L1 genes. Between 2012 and 2015, a total of 138 (0.8%, 138/17669) women with single HPV18 infection were selected in this study. Finally, we observed 122 HPV18 isolates of the complete E6-E7-L1 sequences, and obtained 36 distinct variation patterns which the accession GenBank numbers as KY457805-KY457840. Except KY457805, KY457813, KY457819, KY457827, KY457829, the rest of HPV18 isolates (81.1%, 31/36) are novel variants. All of HPV18 variants belong to lineage A, while no lineage B, and C was found in our population of Taizhou region, Southeast China. Sublineage A1 was the most common variants (85.2%, 104/122), followed by sublineage A4, A3 and A5, while no sublineage A2 was obtained. Based on the tree topologies, there were three newly identified candidates' sublineages A6-A8. Out of 122 women, 67 (54.9%) had diagnosed by biopsy, including 49 women who diagnosed with cervicitis, 12 with cervical intraepithelial neoplasia (CIN)1, 4 with CIN2/3, and 2 with adenocarcinomas, respectively. Nevertheless, there was no association between HPV18 (sub) lineages and CIN1 or worse (CIN1+) lesions comparing with normal biopsies (P = .469). In conclusion, knowledge of the distribution of geographic/ethnical HPV18 genetic diversity provides critical information for developing diagnostic probes, epidemiologic correlate of cervical cancer risk and design of HPV vaccines for targeted populations.

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

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

Efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine in Chinese women aged 18-25 years: event-triggered analysis of a randomized controlled trial

We previously reported the results of a phase II/III, double‐blind, randomized controlled study in Chinese women (NCT00779766) showing a 94.2% (95% confidence interval: 62.7–99.9) HPV‐16/18 AS04‐adjuvanted vaccine efficacy (VE) against cervical intraepithelial neoplasia grade 1 or higher (CIN1+) and/or 6‐month (M) persistent infection (PI) with a mean follow‐up of <2 years, and immunogenicity until 7 months post‐dose 1. Here, we report efficacy and safety results from an event‐triggered analysis with ~3 years longer follow‐up, and immunogenicity until M24. Healthy 18–25‐year‐old women (N = 6051) were randomized (1:1) to receive three doses of HPV‐16/18 vaccine or Al(OH)₃ (control) at M0, 1, 6. VE against HPV‐16/18‐associated CIN2+, and cross‐protective VE against infections with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. In the according‐to‐protocol efficacy cohort, in initially seronegative/DNA‐negative women (vaccine group: N = 2524; control group: N = 2535), VE against HPV‐16/18‐associated CIN2+ was 87.3% (5.3–99.7); VE against incident infection or against 6‐month persistent infection associated with HPV‐31/33/45 was 50.1% (34.3–62.3) or 52.6% (24.5–70.9), respectively. At least, 99.6% of HPV‐16/18‐vaccines remained seropositive for anti‐HPV‐16/18 antibodies; anti‐HPV‐16 and ‐18 geometric mean titers were 1271.1 EU/mL (1135.8–1422.6) and 710.0 EU/ml (628.6–801.9), respectively. Serious adverse events were infrequent (1.7% vaccine group [N = 3026]; 2.5% control group [N = 3026]). Of the 1595 reported pregnancies, nine had congenital anomalies (five live infants, three elective terminations, one stillbirth) that were unlikely vaccination‐related (blinded data). VE against HPV‐16/18‐associated CIN2+ was demonstrated and evidence of cross‐protective VE against oncogenic HPV types was shown. The vaccine was immunogenic and had an acceptable safety profile.