A review of cross-protection against oncogenic HPV by an HPV-16/18 AS04-adjuvanted cervical cancer vaccine: importance of virological and clinical endpoints and implications for mass vaccination in cervical cancer prevention

Fibroblasts Regulate the Transformation Potential of Human Papillomavirus-positive Keratinocytes

Persistent human papillomavirus (HPV) infection is necessary but insufficient for viral oncogenesis. Additional contributing co-factors, such as immune evasion and viral integration have been implicated in HPV-induced cancer progression. It is widely accepted that HPV+ keratinocytes require co-culture with fibroblasts to maintain viral episome expression, yet the exact mechanisms for this have yet to be elucidated. Here we present comprehensive RNA sequencing and proteomic analysis demonstrating that fibroblasts not only support the viral life cycle, but reduce HPV+ keratinocyte transformation. Our co-culture models offer novel insights into HPV-related transformation mechanisms.

Therapeutic Role of HPV Vaccination on Benign HPV-induced Epithelial Proliferations in Immunocompetent and Immunocompromised Patients: Case Study and Review of the Literature

Human papillomavirus (HPV) vaccination represents a milestone in primary prevention of sexually transmitted infections. However, little is known about its possible effects on already established HPV infections. We report the case of a 9-year-old immunosuppressed girl with refractory warts, successfully treated with the nonavalent-HPV vaccine and review the literature about the therapeutic effects of HPV vaccination on benign HPV-induced epithelial proliferations in immunocompetent and immunosuppressed patients. In the literature, promising results were shown on cutaneous warts after HPV vaccination, especially in children and young adults, also in immunosuppressed patients, whereas controverse results were found on anogenital warts. These findings suggest a critical need for randomized clinical trials to assess the efficacy of HPV vaccination in the treatment of benign HPV-induced epithelial proliferations.

A study on the correlation between the prognosis of HPV infection and lesion recurrence after cervical conization

Introduction

Persistent human papillomavirus infection is an important factor in the development of cervical cancer, which is usually a long process evolving from the development of squamous intraepithelial lesions (SIL), also referred to as cervical intraepithelial neoplasia (CIN). Local treatment of advanced squamous intraepithelial lesions, also regarded as High-Grade Squamous Intraepithelial Lesion, may be effective in preventing cancer.

Objective

To promptly identify high-risk patients with a tendency to recurrence.

Methods

We retrospectively analyzed the clinical data of 300 patients with high-grade squamous intraepithelial lesions of the cervix admitted to the Second Affiliated Hospital of Dalian Medical University from 2019 to 2020 to investigate the relationship between recurrence of cervical lesions and postoperative regression of HPV infection, as well as other related risk factors.

Results

We found that the HPV-negative rates were 81.81, 85.71, and 90.91% at 6, 12, and 24 months, respectively, and the average lesion recurrence rate was 8.16%, with a median time to recurrence of 14 months in patients undergoing CKC for HSIL. The risk of cervical squamous intraepithelial lesions was highest in patients with HPV16. Patients over 61 years of age had the lowest postoperative HPV-negative rate. The conversion rate was significantly lower in patients with multiple HPV genotypes than in those with single HPV infection (p < 0.05). The probability of recurrence was higher in patients with the same HPV infection genotype before and after surgery than in patients with different infection genotypes before and after surgery (p < 0.05).

Conclusion

Combined with the literature review, we believe that patients aged ≥50 years, with ≥3 pregnancies and births, a history of smoking, and consistent genotypes of preoperative and postoperative HPV infection in cervical conization have more HPV re-infection or persistent infection, and that these factors may be high-risk factors for lesion recurrence. For patients with possible potential high-risk factors, we need to carry out individualized follow-up and focused management, take timely and effective management measures, optimize the treatment plan, reduce the recurrence rate, prevent HSIL and cervical cancer, improve the quality of patient's survival, and improve the prognosis.

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).

Human papillomavirus vaccination in women undergoing excisional treatment for cervical intraepithelial neoplasia and subsequent risk of recurrence: A systematic review and meta-analysis

INTRODUCTION

In this review and meta-analysis we aimed to investigate whether human papilloma virus (HPV) vaccination administered after excisional treatment of cervical intraepithelial neoplasia (CIN) is associated with a reduced risk of recurrence of CIN grade 2 or worse (CIN2+).

MATERIAL AND METHODS

We performed a systematic literature search in three online databases through June 2021. Observational studies and randomized controlled trials (RCTs) were eligible for inclusion if the prophylactic HPV vaccine was administered after excisional treatment for histologically verified CIN. Only English language literature was included. The primary outcome measure was recurrence of CIN2+ after treatment. A meta-analysis was performed using fixed and random-effects models, and results were reported as pooled odds ratios (OR) with 95% confidence intervals (95% CI). Quality assessment was performed using ROB2-tool for RCTs and ROBINS-I for observational studies. The protocol was registered in PROSPERO (CRD42021238257).

RESULTS

A total of 1561 studies were identified, of which nine, including 19 971 women, were included. Two studies were RCTs and seven were observational studies. Using the fixed-effect model on the two RCTs, the OR for recurrence of CIN2+ was 0.29 (95% CI 0.16-0.53). Due to considerable heterogeneity in observational studies, the random-effects model was used to estimate pooled OR for CIN2+ recurrence in these studies. Thus, using unadjusted data from observational studies, the OR for CIN2+ recurrence was 0.35 (95% CI 0.18-0.67), whereas when using adjusted data, the OR for CIN2+ recurrence was 0.54 (95% CI 0.21-1.35). However, quality assessment revealed a serious risk of bias for the majority of the studies included.

CONCLUSIONS

HPV vaccination post-treatment was associated with a significantly reduced risk of CIN2+ recurrence when using unadjusted estimates from observational studies and RCTs. We found no significant effect of HPV vaccination on risk of CIN2+ recurrence when using the outcome measure from observational studies with the least risk of bias. Large, well-designed randomized placebo-controlled trials are needed to determine whether post-treatment HPV vaccination should be recommended to all women undergoing excisional treatment for CIN.

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.

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.

Potential health impact and cost-effectiveness of bivalent human papillomavirus (HPV) vaccination in Afghanistan

INTRODUCTION

Human papillomavirus (HPV) vaccination has not been introduced in many countries in South-Central Asia, including Afghanistan, despite the sub-region having the highest incidence rate of cervical cancer in Asia. This study estimates the potential health impact and cost-effectiveness of HPV vaccination in Afghanistan to inform national decision-making.

METHOD

An Excel-based static cohort model was used to estimate the lifetime costs and health outcomes of vaccinating a single cohort of 9-year-old girls in the year 2018 with the bivalent HPV vaccine, compared to no vaccination. We also explored a scenario with a catch-up campaign for girls aged 10-14 years. Input parameters were based on local sources, published literature, or assumptions when no data was available. The primary outcome measure was the discounted cost per disability-adjusted life-year (DALY) averted, evaluated from both government and societal perspectives.

RESULTS

Vaccinating a single cohort of 9-year-old girls against HPV in Afghanistan could avert 1718 cervical cancer cases, 125 hospitalizations, and 1612 deaths over the lifetime of the cohort. The incremental cost-effectiveness ratio was US$426 per DALY averted from the government perspective and US$400 per DALY averted from the societal perspective. The estimated annual cost of the HPV vaccination program (US$3,343,311) represents approximately 3.53% of the country's total immunization budget for 2018 or 0.13% of total health expenditures.

CONCLUSION

In Afghanistan, HPV vaccine introduction targeting a single cohort is potentially cost-effective (0.7 times the GDP per capita of $586) from both the government and societal perspective with additional health benefits generated by a catch-up campaign, depending on the government's willingness to pay for the projected health outcomes.

Human Papillomavirus awareness and vaccine acceptability among men who have sex with men from mainland China

Reductions in persistent HPV infection and related diseases occurrence have been proved among vaccinated males. However, little was known on awareness of HPV and the vaccine in males, especially in high-risk subgroups such as men who have sex with men (MSM), in China. A multicenter cross-sectional study was conducted in MSM from 10 selected cities in mainland China. HPV awareness and vaccination acceptability were investigated through interviews and questionnaires. In total, 3057 eligible participants aged 18 years older from 10 cities were investigated. Only 20.6% (629/3057) of them had ever heard of HPV and 4.8% (146/3057) had heard of HPV vaccine. Factors that potentially influence willingness for HPV vaccination were found to be safety of the vaccine (54.2%, 1656/3057) and severity of HPV infection (52.3%, 1599/3057). After education, 97.8% (2882/2946) of participants would like to pay for HPV vaccination, and only a minority of them (2.5%, 75/2946) would like to afford more than 2000 RMB. Our results showed that the awareness on HPV and the vaccine were quite poor among MSM in mainland China. To promote the application of HPV vaccination in male populations, appropriate information delivery and education on HPV infection and health should be enhanced as well as in females.

Cervical cancer in Zimbabwe: a situation analysis

INTRODUCTION

Despite the wide-spread availability of cervical cancer prevention and screening programs in developed countries, the morbidity and mortality rates of cervical cancer in Zimbabwe are still very high. Limited resources as well as the high HIV prevalence are contributors to the high burden of cervical cancer. This paper aims to analyse the policies, frameworks and current practices in the management of cervical cancer in Zimbabwe.

METHODS

A review of national documents and published literature on cervical cancer prevention, screening, treatment and knowledge in Zimbabwe was done. Informal interviews were conducted to assess the practices of cervical cancer management.

RESULTS

Through strategic collaboration, a pilot for the HPV vaccination program is underway. The VIAC national cervical cancer screening program is being adopted into the current healthcare system. With regards to the treatment of precancerous lesions we found that the "see and treat" program has been implemented in colposcopy clinics. In addition, there are two multidisciplinary cancer treatment clinics installed in two central public hospitals. The general knowledge and understanding of cervical cancer is poor in Zimbabwe.

CONCLUSION

Limitations in resources, infrastructure, manpower, delays in treatment and patient knowledge play a role in the high morbidity and mortality of cervical cancer in Zimbabwe. The Ministry of Health needs to increase funding to expedite the availability of HPV vaccine and screening programs. Community engagement initiatives to raise awareness on cervical cancer should be established to provide education on how to prevent the development of cervical cancer, as well as promote screening for early detection.

Knowledge of Human Papillomavirus Infection, Cervical Cancer and Willingness to pay for Cervical Cancer Vaccination among Ethnically Diverse Medical Students in Malaysia

The primary objective of this study was to assess the knowledge of medical students and determine variation between different cultural groups. A secondary aim was to find out the willingness to pay for cervical cancer vaccination and the relationships between knowledge and attitudes towards Human Papillomavirus vaccination. A cross-sectional survey was conducted in a private medical university between June 2014 and November 2014 using a convenient sampling method. A total of 305 respondents were recruited and interviewed with standard questionnaires for assessment of knowledge, attitudes and practice towards human papilloma virus and their willingness to pay for HPV vaccination. Knowledge regarding human papilloma virus, human papilloma virus vaccination, cervical cancer screening and cervical cancer risk factors was good. Across the sample, a majority (90%) of the pupils demonstrated a high degree of knowledge about cervical cancer and its vaccination. There were no significant differences between ethnicity and the participants' overall knowledge of HPV infection, Pap smear and cervical cancer vaccination. Some 88% of participants answered that HPV vaccine can prevent cervical cancer, while 81.5% of medical students said they would recommend HPV vaccination to the public although fewer expressed an intention to receive vaccination for themselves.

Immunoprevention of human papillomavirus-associated malignancies

Persistent infection by one of 15 high-risk human papillomavirus (hrHPV) types is a necessary but not sufficient cause of 5% of all human cancers. This provides a remarkable opportunity for cancer prevention via immunization. Since Harald zur Hausen's pioneering identification of hrHPV types 16 and 18, found in approximately 50% and 20% of cervical cancers, respectively, two prophylactic HPV vaccines containing virus-like particles (VLP) of each genotype have been widely licensed. These vaccines are beginning to affect infection and HPV-associated neoplasia rates after immunization campaigns in adolescents. Here, we review recent progress and opportunities to better prevent HPV-associated cancers, including broadening immune protection to cover all hrHPV types, reducing the cost of HPV vaccines especially for developing countries that have the highest rates of cervical cancer, and immune-based treatment of established HPV infections. Screening based upon George Papanicolaou's cervical cytology testing, and more recently detection of hrHPV DNA/RNA, followed by ablative treatment of high-grade cervical intraepithelial neoplasia (CIN2/3) have substantially reduced cervical cancer rates, and we examine their interplay with immune-based modalities for the prevention and eventual elimination of cervical cancer and other HPV-related malignancies.

Human papillomavirus prevalence in paired urine and cervical samples in women invited for cervical cancer screening

With the introduction of Human papillomavirus (HPV) vaccination in young girls in 2007, it is important to monitor HPV infections and epidemiological changes in this target population. The present study has evaluated the detection of human papillomavirus DNA in paired cervical and urine samples to understand if HPV testing in urine could be used as non-invasive method to monitor HPV status in young women. The study enrolled 216 twenty five-year-old women, resident in Florence and invited for the first time to the cervical cancer Screening Program within a project evaluating the impact of HPV vaccination. HPV genotyping was performed on 216 paired urine and cervical samples. The overall concordance between cervix and urine samples, investigated by HPV genotyping (INNO-LiPA HPV Genotyping Extra), was: 85.6% (184/215), 84.6% (182/215), 80% (172/215) when the same HPV, at least the same HR HPV and all HR HPV, respectively, were detected. HPV type specific concordance in paired urine and cervical samples was observed in 85.8% (175/204) of women with normal cytology and in seven out of nine women with abnormal cytology. Urine seems to be a suitable and reliable biological material for HPV DNA detection as evidenced by the high concordance with HPV detected in cervical samples. These results suggest that urine could be a good noninvasive tool to monitor HPV infection in vaccinated women.

Human papillomavirus genotypes in cervical cancer and vaccination challenges in Zimbabwe

Cervical cancer is one of the major causes of morbidity and mortality in women in Zimbabwe. This is mainly due to the high prevalence of high-risk human papillomavirus (HPV) genotypes in the population. So far, few studies have been done that showed the presence of high-risk genital HPV genotypes such as 16, 18, 31, 33, 52, 58 and 70 in Zimbabwean women with cervical cancer. The prevalence of HPV DNA in women with cervical cancer has been shown to range from 63% to 98%. The high-risk HPV 16, 18, 31, 33 and 58 were the most common genotypes in all the studies. The introduction of the new HPV vaccines, HPV2 and HPV4, which protect against HPV genotypes 16 and 18 into Zimbabwe is likely to go a long way in reducing deaths due to cervical cancer. However, there are few challenges to the introduction of the vaccines. The target population for HPV vaccination is at the moment not well-defined. The other challenge is that the current HPV vaccines confer only type-specific (HPV 16 and 18) immunity leaving a small proportion of Zimbabwean women unprotected against other high-risk HPV genotypes such as 31, 33 and 58. Future HPV vaccines such as the nanovalent vaccine will be more useful to Zimbabwe as they will protect women against more genotypes.

Human papillomavirus community in healthy persons, defined by metagenomics analysis of human microbiome project shotgun sequencing data sets

Human papillomavirus (HPV) causes a number of neoplastic diseases in humans. Here, we show a complex normal HPV community in a cohort of 103 healthy human subjects, by metagenomics analysis of the shotgun sequencing data generated from the NIH Human Microbiome Project. The overall HPV prevalence was 68.9% and was highest in the skin (61.3%), followed by the vagina (41.5%), mouth (30%), and gut (17.3%). Of the 109 HPV types as well as additional unclassified types detected, most were undetectable by the widely used commercial kits targeting the vaginal/cervical HPV types. These HPVs likely represent true HPV infections rather than transitory exposure because of strong organ tropism and persistence of the same HPV types in repeat samples. Coexistence of multiple HPV types was found in 48.1% of the HPV-positive samples. Networking between HPV types, cooccurrence or exclusion, was detected in vaginal and skin samples. Large contigs assembled from short HPV reads were obtained from several samples, confirming their genuine HPV origin. This first large-scale survey of HPV using a shotgun sequencing approach yielded a comprehensive map of HPV infections among different body sites of healthy human subjects.

IMPORTANCE

This nonbiased survey indicates that the HPV community in healthy humans is much more complex than previously defined by widely used kits that are target selective for only a few high- and low-risk HPV types for cervical cancer. The importance of nononcogenic viruses in a mixed HPV infection could be for stimulating or inhibiting a coexisting oncogenic virus via viral interference or immune cross-reaction. Knowledge gained from this study will be helpful to guide the designing of epidemiological and clinical studies in the future to determine the impact of nononcogenic HPV types on the outcome of HPV infections.

Influence of HIV-1 and/or HIV-2 infection and CD4 count on cervical HPV DNA detection in women from Senegal, West Africa

BACKGROUND

HIV infection is associated with greater risk of precancerous lesions and cervical cancer in women. However, several factors remain unclarified regarding the association between HIV infection and HPV detection, especially among those with HIV type 2 versus type 1 infection and severely immunocompromised persons.

OBJECTIVES

To evaluate HPV overall and type-specific detection among HIV-infected and uninfected women in Senegal.

STUDY DESIGN

Detection of HPV DNA for 38 genotypes in cervical swabs using PCR-based methods was evaluated in HIV-positive (n=467) and HIV-negative (n=2139) women participating in studies in Senegal. Among HIV-1 and/or HIV-2 positive women, CD4 counts were assessed. Adjusted multivariable prevalence ratios (PR) were calculated.

RESULTS

The prevalence of any HPV DNA and multiple HPV types was greater among HIV-infected individuals (78.2% and 62.3%, respectively) compared with HIV-negative women (27.1% and 11.6%). This trend was also seen for HPV types 16 and 18 (13.1% and 10.9%) compared to HIV-negative women (2.2% and 1.7%). HIV-infected women with CD4 cell counts less than 200 cells/μl had a higher likelihood of any HPV detection (PRa 1.30; 95% CI 1.07-1.59), multiple HPV types (PRa 1.52; 95% CI 1.14-2.01), and HPV-16 (PRa 9.00; 95% CI 1.66-48.67), but not HPV-18 (PRa 1.20, 95% CI 0.45-3.24) compared to those with CD4 counts 500 cells/μl or above.

CONCLUSION

HIV-infected women, especially those most severely immunocompromised, are more likely to harbor HPV. Measures to prevent initial HPV infection and subsequent development of cervical cancer through focused screening efforts should be implemented in these high risk populations.

Are the currently existing anti-human papillomavirus vaccines appropriate for the developing world?

Cervical cancer prevention is expected to be achieved by vaccination of girls 2-3 years before sexual debut, and cervical smear cytology follow-up. The existing human papillomavirus (HPV) vaccines target the low-risk 6 and 11, and the high-risk 16 and 18 subtypes, the most common agents of ano-genital pre-invasive and invasive lesions. We conducted the review by searching PubMed using the terms "HPV," "HPV subtypes," "developing world," and "HPV-vaccine" to retrieve articles published between 2000 and 2011. We focused on studies that were relevant to the developing world. The proposed vaccination policy is currently unachievable in the developing world because of the cost of the vaccine, the lack of adequate cytology and follow-up infrastructures. Moreover, the subtypes of HPV involved in cervical pathology, their associations, and natural history (clearance and persistence rates) differ from the industrialized world. Therefore, the current bivalent and quadrivalent anti-HPV vaccines are unlikely to achieve their target in the developing world. It follows from published data that there is an obligation of the pharmaceutical industry and of the public-health policy makers not to embark on mass vaccination campaigns without thorough information and investigation of the local relevance.

HPV vaccine cross-protection: Highlights on additional clinical benefit

Prophylactic human papillomavirus (HPV) vaccines are administered in vaccination programs, targeted at young adolescent girls before sexual exposure, and in catch-up programs for young women in some countries. All the data indicate that HPV-virus-like particles (VLPs) effectively prevent papillomavirus infections with a high level of antibodies and safety. Since non-vaccine HPV types are responsible for about 30% of cervical cancers, cross-protection would potentially enhance primary cervical cancer prevention efforts. High levels of specific neutralizing antibodies can be generated after immunization with HPV VLPs. Immunity to HPV is type-specific. However, if we consider the phylogenetic tree including the different HPV types, we realize that a certain degree of cross-protection is possible, due to the high homology of some viral types with vaccine ones. The assessment of cross-protective properties of HPV vaccines is an extremely important matter, which has also increased public health implications and could add further value to their preventive potential. The impact of cross-protection is mostly represented by a reduction of cervical intraepithelial neoplasia CIN2-3 more than what expected. In this article we review the mechanisms and the effectiveness of Bivalent (HPV-16/-18) and Quadrivalent (HPV-6/-11/-16/-18) HPV vaccine cross-protection, focusing on the critical aspects and the potential biases in clinical trials, in order to understand how cross-protection could impact on clinical outcomes and on the new perspectives in post-vaccine era.

HPV vaccination and cervical cancer

Cervical cancer is the third most common cancer in women worldwide and often affects women under 40 years with young families. Vaccination against the human papillomavirus (HPV) is a major advance, since it offers primary prevention against the infectious agent that is the main cause of the disease. Two prophylactic vaccines have shown great promise in clinical trials. One of these (Gardasil(®)) contains all four HPV types, offering protection against genital warts (types 6 and 11) as well as cervical cancer (types 16 and 18). The other (Cervarix(®)) contains types 16 and 18, targeting cervical cancer alone, but also has a degree of cross-protection against types 31 and 45, which could significantly increase the level of protection. Adolescent girls remain the primary target of vaccination programmes, but the issues of vaccinating boys and older women are increasingly debated.

Detection of systemic and mucosal HPV-specific IgG and IgA antibodies in adolescent girls one and two years after HPV vaccination

The bivalent HPV16/18 vaccine induces high antibody concentrations in serum while data about antibody responses in the cervix are limited. In this study, we investigated pre- and post-vaccination antibody responses against seven high-risk HPV types by detection of IgG and IgA HPV-specific antibodies in cervical secretion samples (CVS) and serum. From an HPV vaccine monitoring study CVS and serum samples were available (pre-vaccination (n = 297), one year (n = 211) and two years (n = 141) post-dose-one vaccination) from girls aged 14-16 y. The girls were vaccinated with the bivalent HPV vaccine at months 0, 1 and 6. CVS was self-sampled using a tampon. Samples were tested for HPV-specific antibodies (HPV16/18/31/33/45/52/58) by a VLP-based multiplex immunoassay. Post-vaccination, IgG and IgA antibody levels for HPV16/18 were detectable in CVS and amounted to 2% and 1% of the IgG and IgA antibody levels observed in serum, respectively. The antibody levels remained constant between one and two years after vaccination. The correlation between CVS and serum was similar for IgG and IgA vaccine-derived antibody levels for HPV16 (rs = 0.58, rs = 0.54) and HPV18 (rs = 0.50, rs = 0.55). Vaccine-derived IgG antibody levels against cross-reactive HPV types in CVS and in serum were highest for HPV45. No IgA cross-reactive antibody responses could be detected in CVS. Post-vaccination, HPV16/18 IgG and IgA antibodies are not only detectable in serum but also in CVS. The correlation of HPV16/18 IgG antibody levels between serum and CVS suggests that vaccine induced HPV antibodies transudate and/or exudate from the systemic circulation to the cervical mucosa to provide protection against HPV infections.

Cross-protective efficacy of two human papillomavirus vaccines: a systematic review and meta-analysis

BACKGROUND

The extent of cross-protection is a key element in the choice of human papillomavirus (HPV) vaccine to use in vaccination programmes. We compared the cross-protective efficacy of the bivalent vaccine (HPV 16 and 18; Cervarix, GlaxoSmithKline Biologicals, Rixensart, Belgium) and quadrivalent vaccine (HPV 6, 11, 16, and 18; Gardasil, Merck, Whitehouse Station, NJ, USA) against non-vaccine type HPVs.

METHODS

We searched Medline and Embase databases, conference abstracts, and manufacturers' websites for randomised clinical trials assessing the efficacy of bivalent and quadrivalent vaccines against persistent infections (lasting ≥6 months) and cervical intraepithelial neoplasia (CIN) associated with the non-vaccine type HPVs (types 31, 33, 45, 52, and 58). We included studies of participants who were HPV DNA negative before vaccination for all HPV types assessed. We assessed heterogeneity in vaccine efficacy estimates between trials with I(2) and χ(2) statistics.

FINDINGS

We identified two clinical trials (Females United to Unilaterally Reduce Endo/Ectocervical Disease [FUTURE] I and II) of the quadrivalent vaccine and three (Papilloma Trial Against Cancer In Young Adults [PATRICIA], HPV007, and HPV-023) of the bivalent vaccine. Analysis of the most comparable populations (pooled FUTURE I/II data vs PATRICIA) suggested that cross-protective vaccine efficacy estimates against infections and lesions associated with HPV 31, 33, and 45 were usually higher for the bivalent vaccine than the quadrivalent vaccine. Vaccine efficacy in the bivalent trial was higher than it was in the quadrivalent trial against persistent infections with HPV 31 (77·1% [95% CI 67·2 to 84·4] for bivalent vaccine vs 46·2% [15·3 to 66·4] for quadrivalent vaccine; p=0·003) and HPV 45 (79·0% [61·3 to 89·4] vs 7·8% [-67·0 to 49·3]; p=0·0003), and against CIN grade 2 or worse associated with HPV 33 (82·3% [53·4 to 94·7] vs 24·0% [-71·2 to 67·2]; p=0·02) and HPV 45 (100% [41·7 to 100] vs -51·9% [-1717·8 to 82·6]; p=0·04). We noted substantial heterogeneity between vaccine efficacy in bivalent trials against persistent infections with HPV 31 (I(2)=69%, p=0·04) and HPV 45 (I(2)=70%, p=0·04), with apparent reductions in cross-protective efficacy with increased follow-up.

INTERPRETATION

The bivalent vaccine seems more efficacious against non-vaccine HPV types 31, 33, and 45 than the quadrivalent vaccine, but the differences were not all significant and might be attributable to differences in trial design. Efficacy against persistent infections with types 31 and 45 seemed to decrease in bivalent trials with increased follow-up, suggesting a waning of cross-protection; more data are needed to establish duration of cross-protection.

FUNDING

Public Health Agency of Canada.

Comparison of the immune responses to the CIA06-adjuvanted human papillomavirus L1 VLP vaccine with those against the licensed HPV vaccine Cervarix™ in mice

CIA05 is a toll-like receptor (TLR) 4 agonist derived from an Escherichia coli lipopolysaccharide (LPS) mutant and has been shown to have potential as a vaccine adjuvant. In this study, we investigated the immunopotentiating activity of the adjuvant system CIA06, which is comprised of CIA05 and aluminum hydroxide (alum), when used with the human papillomavirus (HPV) L1 virus-like particles (VLPs) vaccine. BALB/c mice were immunized intramuscularly three times at 2-week intervals with HPV16 L1 VLPs alone or in the presence of various combinations of CIA05 and alum, and the immune responses were assessed. We found that the combination of CIA05 and alum at a ratio of 1:50 (designated CIA06B) yielded the highest immune response in terms of serum anti-HPV L1 VLP IgG antibody titers, splenocyte interferon (IFN)-γ secretion, and antigen-specific memory B cell responses. The immunogenicity of the CIA06B-adjuvanted HPV16/18 L1 VLP vaccine was compared with that of the currently licensed HPV vaccine Cervarix™. The CIA06B-adjuvanted vaccine was similar to Cervarix™ with regard to eliciting serum antigen-specific IgG antibodies and virus-neutralizing antibodies but more effective at inducing splenic cytokine production and memory B cells. We also observed that the antigen-specific IgG antibody titers, splenic IFN-γ secretion and memory B cells induced by the CIA06B-adjuvanted HPV vaccine remained high up to 24 weeks post-immunization. Based on these data, we concluded that CIA06B may have potential as an adjuvant in a potent prophylactic vaccine against HPV infection.

Human papillomavirus type-specific prevalence in women with cervical intraepithelial neoplasm in Western China

Human papillomavirus (HPV) type-specific prevalence was studied in 600 cases of cervical intraepithelial neoplasm in western China by GenoArray test. HPV-16 and -58 were the most prevalent types, with prevalences of 37.8% and 21.8%, respectively. HPV-18 and -45 were uncommon types. The results show different type distributions from that of other regions, which is important evidence for the selection of future genotypes in HPV vaccines in western China.

Next-generation treatment strategies for human papillomavirus-related head and neck squamous cell carcinoma: where do we go?

Oncogenic human papillomavirus (HPV) is currently recognised as a major risk factor for the development of head and neck squamous cell carcinomas (HNSCC). HPV is mostly detected in tumours arising from the oropharynx and more specifically from the tonsil. HPV-related tumours display clinical and molecular characteristics that are distinct from HPV-unrelated tumours, which are generally induced by alcohol and tobacco abuse. Detection of biologically active HPV in HNSCC has prognostic relevance, which warrants the separate classification of HPV-induced tumours and is a prerequisite for further optimisation of treatment protocols for this distinct group. Current guidelines for the treatment of oropharyngeal squamous cell carcinoma (OPSCC) have not incorporated specific treatment modalities for HPV-related tumours. The development of such treatment options is still in a preclinical phase or in early clinical trials. Recent data on treatment response of OPSCC have been obtained by retrospectively analysing HPV-status and indicate that patients with HPV-related tumours show a favourable prognosis, independent of the type of treatment. These patients may benefit from de-intensified treatment, which should be assessed in prospective clinical trials. The development and future use of new antiviral and immunomodulatory therapeutics may be instrumental in this approach to improve survival rates and decrease disease-and-treatment-related morbidity. In this review we will focus on present therapeutic HPV-targeting strategies and discuss future directions for de-intensified treatment of HPV-positive HNSCC.

Epidemiology and burden of HPV infection and related diseases: implications for prevention strategies

Human papillomavirus (HPV) infection is a necessary, although not sufficient cause of cervical cancer. Globally, HPV infection accounts for an estimated 530,000 cervical cancer cases (~270,000 deaths) annually, with the majority (86% of cases, 88% of deaths) occurring in developing countries. Approximately 90% of anal cancers and a smaller subset (<50%) of other cancers (oropharyngeal, penile, vaginal, vulvar) are also attributed to HPV. In total, HPV accounts for 5.2% of the worldwide cancer burden. HPVs 16 and 18 are responsible for 70% of cervical cancer cases and, especially HPV 16, for a large proportion of other cancers. Prophylactic vaccination targeting these genotypes is therefore expected to have a major impact on the burden of cervical cancer as well as that of other HPV-related cancers. Over the past 50 years, organized or opportunistic screening with Papanicolaou (Pap) cytology has led to major reductions in cervical cancer in most developed countries. However, due to lack of resources or inadequate infrastructure, many countries have failed to reduce cervical cancer mortality through screening. HPV DNA testing recently emerged as a likely candidate to replace Pap cytology for primary screening. It is less prone to human error and more sensitive than Pap in detecting high-grade cervical lesions. For countries with national vaccination programs, HPV testing may also serve as a low cost strategy to monitor long term vaccine efficacy. Introduction of well organized vaccination and screening programs should be a priority for all countries. Increased support from donors is needed to support this cause.

Prevention of persistent human papillomavirus infection by an HPV16/18 vaccine: a community-based randomized clinical trial in Guanacaste, Costa Rica

Target groups for human papillomavirus (HPV) vaccination are controversial. We evaluated vaccine efficacy (VE) against 1-year persistent infection, stratified by age and sexual behavior, among young women in Costa Rica. We randomized 7,466 healthy women 18 to 25 years of age to HPV16/18 or hepatitis A vaccine (follow-up, 50.4 months). According-to-protocol (ATP) cohorts included compliant HPV-negative women; intention-to-treat (ITT) included all randomized women. ATP VE was 90.9% (95% CI, 82.0-95.9) against HPV16/18 infections, 44.5% against HPV31/33/45 (95% CI, 17.5-63.1), and 12.4% (95% CI, -3.2 to 25.6) against any oncogenic infection. Overall ITT VE against HPV16/18 infections was 49.0%, but ATP and ITT VE almost reached 100% in year 4 of follow-up. ATP efficacy against HPV16/18 was similar by age, but ITT VE was greatest among youngest women (68.9% among those 18-19 years of age; 21.8% among those 24-25 years of age) and 79.8% among virgins. Among previously unexposed women, vaccination is highly efficacious against HPV16/18 and partially against HPV31/33/45. Vaccination is most effective in women and girls before they initiate sexual activity, with programmatic and individual decision implications.

HPV infection among rural American Indian women and urban white women in South Dakota: an HPV prevalence study

Background

High-risk strains of human papillomavirus (HPV) cause cervical cancer. American Indian (AI) women in the Northern Plains of the U.S. have significantly higher incidence and mortality rates for cervical cancer than White women in the same geographical area. We compared HPV prevalence, patterns of HPV types, and infection with multiple HPV types in AI and White women living in South Dakota, U.S.

Methods

We analyzed the HPV status of cervical samples collected in 2006-2008 from women aged 18-65 years who attended two rural AI reservation clinics (n = 235) or an urban clinic in the same area serving mostly White women (n = 246). Data collection occurred before HPV vaccination was available to study participants. HPV DNA was amplified by using the L1 consensus primer system and an HPV Linear Array detection assay to identify HPV types. We used chi-square tests to compare HPV variables, with percentages standardized by age and lifetime number of sexual partners.

Results

Compared to White women, AI women were younger (p = 0.01) and reported more sexual partners (p < 0.001). A lower percentage of AI women tested negative for HPV infection compared to Whites (58% [95% CI = 51-65] vs. 77% [95% CI = 71-82]; p < 0.001), and a higher percentage of AI women were infected by oncogenic types (30% [95% CI = 25-36] vs. 16% [95% CI = 11-21]; p = 0.001). Infections among AI women showed a wider variety and very different pattern of HPV types, including a higher prevalence of mixed HPV infections (19% [95% CI = 26-38] vs. 7% [95% CI = 4-11]; p = 0.001). AI women had a higher percentage of HPV infections that were not preventable by HPV vaccination (32% [95% CI = 26-38] vs. 15% [95% CI = 11-21]; p < 0.001).

Conclusions

A higher HPV burden and a different HPV genotyping profile may contribute to the high rate of cervical cancer among AI women.

Detection of human papillomavirus DNA in urine. A review of the literature

The detection of human papillomavirus (HPV) DNA in urine, a specimen easily obtained by a non-invasive self-sampling method, has been the subject of a considerable number of studies. This review provides an overview of 41 published studies; assesses how different methods and settings may contribute to the sometimes contradictory outcomes; and discusses the potential relevance of using urine samples in vaccine trials, disease surveillance, epidemiological studies, and specific settings of cervical cancer screening. Urine sampling, storage conditions, sample preparation, DNA extraction, and DNA amplification may all have an important impact on HPV DNA detection and the form of viral DNA that is detected. Possible trends in HPV DNA prevalence in urine could be inferred from the presence of risk factors or the diagnosis of cervical lesions. HPV DNA detection in urine is feasible and may become a useful tool but necessitates further improvement and standardization.

A novel, broad spectrum therapeutic HPV vaccine targeting the E7 proteins of HPV16, 18, 31, 45 and 52 that elicits potent E7-specific CD8T cell immunity and regression of large, established, E7-expressing TC-1 tumors

Persistent infection by high risk genotypes of human papillomavirus (HPV) is the cause of cervical cancer, which remains one of the most common cancers among women worldwide. In addition, there is a growing appreciation that high risk HPVs are associated with a number of other cancers including anogenital cancers as well as a subset of head and neck cancers. Recently, prophylactic HPV vaccines targeting the two most prevalent high risk HPVs (HPV16 and HPV18) have been deployed in large-scale vaccination campaigns. However, the extent to which these prophylactic vaccines confer protection against other high risk HPV genotypes is largely unknown and prophylactic vaccines have been shown to be ineffective against pre-existing infection. Thus there continues to be an urgent need for effective therapeutic vaccines against HPV. The E7 protein of HPV16 has been widely studied as a target for therapeutic vaccines in HPV-associated cancer settings because HPV16 is the most prevalent of the high risk HPV genotypes. However, HPV16 accounts for only about 50% of cervical cancers and there are at least 15 other high risk HPVs that are known to be oncogenic. We have developed a novel, broad-spectrum, therapeutic vaccine (Pentarix) directed at the E7 proteins from five of the most prevalent high-risk genotypes of HPV worldwide (HPV16, 18, 31, 45 and 52) that together account for more than 80% of all HPV-associated cancers. Pentarix is a recombinant protein-based vaccine that elicits strong, multi-genotype specific CD8 T cell immunity when administered to mice in combination with adjuvants comprised of agonists of the TLR3 or TLR9 family of innate immune receptors. Furthermore, large, established E7-expressing TC-1 tumors undergo rapid and complete regression after therapeutic vaccination of mice with Pentarix. Together, these data suggest that Pentarix may be of clinical value for patients with E7-positive, HPV-associated precancerous lesions or malignant disease.

AS04-adjuvanted human papillomavirus (HPV) types 16 and 18 vaccine (Cervarix®): a review of its use in the prevention of premalignant cervical lesions and cervical cancer causally related to certain oncogenic HPV types

The AS04-adjuvanted human papillomavirus (HPV) 16/18 vaccine (Cervarix®) is a noninfectious recombinant vaccine produced using purified virus-like particles (VLPs) that induce a strong immunogenic response eliciting high levels of anti-L1 VLP antibodies that persist at levels markedly greater than those observed with natural infection. The vaccine adjuvant (AS04) is composed of monophosphoryl-lipid A, which enhances cellular and humoral immune response, adsorbed to aluminium hydroxide. The vaccine is indicated for the prevention of premalignant cervical lesions and cervical cancer causally related to certain oncogenic HPV types in females aged ≥10 years. The AS04-adjuvanted HPV 16/18 vaccine administered in a three-dose schedule over 6 months elicits a high immunogenic response and is highly protective against cervical intraepithelial neoplasia and infection causally related to high-risk oncogenic HPV types. In well designed clinical trials in young women aged 15-25 years who were HPV 16/18 seronegative and DNA negative to 14 HPV high-risk types, high levels of immunogenicity and protection were sustained for follow-up periods of up to 8.4 years. High and persistent immunogenicity against infection with HPV 16/18 has also been demonstrated in older and younger females (aged 10-55 years) who were seronegative for vaccine HPV types. The AS04-adjuvanted HPV 16/18 vaccine elicited a greater immunogenic response than the quadrivalent HPV vaccine in women aged 18-45 years who were seronegative and DNA negative for HPV 16/18. The AS04-adjuvanted HPV 16/18 vaccine confers cross protection against certain non-vaccine, high-risk HPV types. A rapid and strong anamnestic humoral immune response was elicited following a fourth dose of the vaccine. The AS04-adjuvanted HPV 16/18 vaccine is generally well tolerated, and pharmacoeconomic analyses have demonstrated the potential for public health benefits and cost effectiveness when vaccination programmes are run in conjunction with screening programmes. Thus, the AS04-adjuvanted HPV 16/18 vaccine prevents cervical disease associated with certain oncogenic HPV types, thereby reducing the burden of premalignant cervical lesions and, very likely, cervical cancer.

Human papillomavirus genotype distribution in Czech women and men with diseases etiologically linked to HPV

BACKGROUND

The HPV prevalence and genotype distribution are important for the estimation of the impact of HPV-based cervical cancer screening and HPV vaccination on the incidence of diseases etiologically linked to HPVs. The HPV genotype distribution varies across different geographical regions. Therefore, we investigated the type-specific HPV prevalence in Czech women and men with anogenital diseases.

METHODS

We analyzed 157 squamous cell carcinoma samples, 695 precancerous lesion samples and 64 cervical, vulvar and anal condylomata acuminate samples. HPV detection and typing were performed by PCR with GP5+/6+ primers, reverse line blot assay and sequencing.

RESULTS

Thirty different HPV genotypes were detected in our study, HPV 16 being the most prevalent type both in precancerous lesions (45%) and squamous cell carcinomas (59%). In benign lesions, HPV 6 (72%) was the most common type. Altogether, 61% of carcinoma samples and 43% of precancerous lesion samples contained HPV 16 and/or 18. The presence of HPV types related to the vaccinal ones (HPV 31, 45, 33, 52, 58) were detected in 16% of carcinoma samples and 18% of precancerous lesion samples. HPV 16 and/or 18 were present in 76% of cervical cancer samples, 33% of CIN1, 43% CIN2 and 71% of CIN3 samples. HPV types 6 and/or 11 were detected in 84% samples of condylomata acuminate samples.

CONCLUSIONS

The prevalence of vaccinal and related HPV types in patients with HPV-associated diseases in the Czech Republic is very high. We may assume that the implementation of routine vaccination against HPV would greatly reduce the burden of HPV-associated diseases in the Czech Republic.

Role of AS04 in human papillomavirus vaccine: mode of action and clinical profile

INTRODUCTION

Understanding the mode of action of adjuvants is important for the interpretation of clinical studies.

AREAS COVERED

This paper discusses how the results of GSK's clinical studies with an AS04-adjuvanted human papillomavirus (HPV) vaccine are supported by the mode of action of AS04. AS04 and antigens must be injected at the same intramuscular site together or within 24 h of each other. AS04 induces local cytokine production leading to increased recruitment of dendritic cells and monocytes and raised numbers of antigen presenting cells in the draining lymph node. The localized and transient nature of the innate immune response supports the acceptable safety profile observed in clinical studies. The readers will gain a comprehensive understanding of the mode of action of AS04 and how it relates to results of clinical studies.

EXPERT OPINION

The AS04-adjuvanted HPV vaccine has an acceptable safety profile and induces an enhanced and sustained immune response and high protection against HPV types 16/18. Cross-protection against oncogenic HPV types 31/33/45 not contained in the vaccine is also observed. The mode of action of AS04 supports the clinical profile of the AS04-adjuvanted HPV vaccine.

Role of adjuvants in modeling the immune response

PURPOSE OF REVIEW

Recent clinical trial results have indicated that it may be possible for vaccines to induce protection against HIV. To build on this result, strategies should be designed to enhance duration, breadth, and magnitude of antibody production. Strategic formulation of agonists of the innate immune system and carriers that selectively present the target antigen yields a class of pharmaceuticals, named 'adjuvants', that greatly influence immunity resulting from vaccination. As researchers begin to focus not only on creating an immune response to an antigen, but also on the quality of that response, the role of adjuvants is becoming increasingly significant. This review is intended to give an overview of recent findings on how adjuvants model the immune response to antigens with a focus on the field of vaccines for HIV.

RECENT FINDINGS

It is clear that innate and adaptive immunity are linked by communication channels that allow innate signals to influence the quality of adaptive responses as well as adaptive signals that temper innate responses. Adjuvants take advantage of this bridge to shape the immune response to antigens. In this review, we will discuss the different classes of adjuvants currently available; recent findings on the relationship between adjuvants and the type of immune profile generated; and the breadth of neutralizing antibodies as influenced by adjuvants.

SUMMARY

Because adjuvants influence the breadth of antibodies generated and the type of cells that proliferate in response to a vaccine this review is relevant for scientists clinicians involved in creating a new HIV vaccine.

Estimating the impact of human papillomavirus (HPV) vaccination on HPV prevalence and cervical cancer incidence in Mali

Human papillomavirus vaccines have potential to reduce cervical cancer incidence and mortality; however, cultural and economic barriers may hinder success in developing countries. We assessed impact of a single vaccine campaign in Mali with use of mathematical modeling. Our model shows that decreases in the prevalence of Human papillomavirus infection are proportional to achieved vaccination coverage.

Prevalence and genotype distribution of human papillomavirus in women with cervical cancer or high-grade precancerous lesions in Chengdu, western China

OBJECTIVE

To study the prevalence and genotype distribution of human papillomavirus (HPV) among women with cervical cancer or high-grade squamous intraepithelial lesions (HSIL) in western China.

METHODS

Cervical cast-off cells from 144 women with cervical cancer and 63 women with HSIL were tested for HPV genotypes using an oligonucleotide microarray.

RESULTS

The overall HPV prevalence was 80.6% in cases of carcinoma and 61.9% in cases of HSIL. The most common genotypes were HPV-16 (carcinoma, 68.1%; HSIL, 34.9%) and HPV-58 (carcinoma, 8.3%; HSIL, 17.5%). Other high-risk types included HPV-18, -31, -33, -35, -45, and -52, with HPV-18 more common in adenocarcinomas than in squamous cell carcinomas (21.4% vs 3.1%; P<0.02). The HPV prevalence was lower among patients older than 49 years (P<0.02).

CONCLUSION

The prevalence of HPV-16 and HPV-58 was high. This finding may help to improve HPV vaccination and cervical cancer prevention programs in western China.

Monitoring of human papillomavirus vaccination

Persistent infection with oncogenic human papillomavirus (HPV) is a necessary causal factor in the development of cervical cancer. Moreover, HPV, predominately type 16 and to a lesser degree type 18, is linked causally to varying proportions of other anogenital cancers (vulva, vagina, penis, anus) as well as cancers elsewhere in the body (oropharynx, larynx, conjunctiva). HPV types 6 and 11 cause most of genital warts and recurrent respiratory papillomatosis. Effective prophylactic vaccines have been developed. In this review, we address briefly the immunological aspects of HPV infection and the results of HPV vaccination trials. Internationally standardized monitoring and evaluation of prophylactic HPV vaccination programmes will be essential for arriving at the most cost-effective strategies for cancer control.

HPV vaccine: an overview of immune response, clinical protection, and new approaches for the future

Although long-term protection is a key-point in evaluating HPV-vaccine over time, there is currently inadequate information on the duration of HPV vaccine-induced immunity and on the mechanisms related to the activation of immune-memory. Longer-term surveillance in a vaccinated population is needed to identify waning immunity, evaluating any requirements for booster immunizations to assess vaccine efficacy against HPV-diseases. Current prophylactic vaccines have the primary end-points to protect against HPV-16 and 18, the genotypes more associated to cervical cancer worldwide. Nevertheless, data from many countries demonstrate the presence, at significant levels, of HPVs that are not included in the currently available vaccine preparations, indicating that these vaccines could be less effective in a particular area of the world. The development of vaccines covering a larger number of HPVs presents the most complex challenge for the future. Therefore, long term immunization and cross-protection of HPV vaccines will be discussed in light of new approaches for the future.

Multinational comparison of diagnostic clues for uterine cervical lesions among cytotechnologists in Asian countries

Vaccination has been underway in several countries for sexually inactive young girls or women against HPV 16 and 18 to prevent them from infection of these HPV types and concurrent cancer development. However, uterine cervical cancers may remain uncontrolled among some Asian countries, where other types of HPV infection are more frequent. A sensitive cancer screening system would remain important for detection of the earlier stage cervical cancers in Asian countries. In this study, 130 cytotechnologists (CTs) in Asian countries (Taiwan 80, Japan 18, Korea 15, Thailand 11, Singapore 3, Bhutan 2, and Mongolia 1) participated in the vote. Selected 10 cervical Pap smears that would be adequate to identify the diagnostic clues especially for atypical squamous cells (ASC) with two or three representative pictures for each case were displayed on the website. The percentages of consistent diagnosis voted by certified CTs with ≥5 years of experience were compared among 10 cervical cases or among Asian countries enrolled. As results, low consistency for ASC cases and high consistency for squamous intraepithelial lesion (SIL) were observed. Examining specimens for the diagnostic clues of ASC in TBS is crucial to maintain the high sensitivity and positive predictive value of SIL in Asian countries.

Medicina moderna: rumo à prevenção, à cura, ao bem-estar e à longevidade

A medicina moderna tem realizado muitas coisas nos campos de doenças infecciosas e de emergências para assistir a cura. Na maior parte dos outros campos, ela visa, sobretudo, ao controle, que é outro nome para o tratamento paliativo. A farmacologia, na qual se inclui a psicofarmacologia, é igualmente dirigida ao controle e ao alívio. Está na hora de profissionais da área e pesquisadores voltarem-se decisivamente para a prevenção e para a cura. Ademais, o outro grande desafio da medicina moderna é a longevidade aliada ao bem-estar. Avanços em vacinas contra hipertensão, diabetes, câncer etc. merecem atenção, bem como o papel da meditação, yoga, espiritualidade etc. na prevenção de doenças em vários níveis. Pesquisas sobre longevidade, mudanças no estilo de vida e centenários saudáveis merecem um exame especialmente minucioso na busca dos fatores que contribuem para a longevidade com bem-estar. Um olhar de perto para a medicina complementar e alternativa é necessário para encontrar modelos apropriados que esta possa vir a ter, à parte seus grandes discursos ou sua hostilidade para com o cuidado médico tradicional. A medicina é uma manifestação do Eros humano, e não deve tornar-se instrumento de seu Tanatos. Ela deve realizar seu verdadeiro potencial, de forma que Eros prevaleça, e Tanatos prevaleça apenas finalmente, não prematuramente.

Multiple human papilloma virus types in cervical infections: competition or synergy?

Coinfection with multiple human papilloma virus (HPV) types is common in cervical HPV infection. To evaluate if infections with different HPV types occur independently, we examined 3558 women above 15 years of age suspected of cervical HPV infection. Among them, 1842 (52%) women were HPV negative and 1716 (48%) were HPV positive as analysed by a PCR-based commercial microarray assay for mucosal types. Of the HPV-positive samples, 824 (48%) had single infections, while 892 (52%) had multiple infections. Observed numbers of concurrent HPV types differed from expected numbers under the assumption of independence between infections by the various HPV types. Significant positive associations were observed for 16 pairs of HPV types in statistical analysis accounting for mass significance. Significant negative associations were also found, i.e. women with HPV-16 infection had 0.4 times the odds of having HPV-51 compared with women not infected with HPV-16. HPV-16 was the only type with odds ratios <1 for all pairwise combinations. While our findings of statistically significant coexistence do not prove biological dependence among HPV types, they do suggest that infections with some HPV types may depend on the existence of certain other HPV types. Any interaction between coexisting HPV types could either decrease or increase the efficacy of current HPV vaccines that offer mainly type-specific protection, depending on whether the types vaccinated against compete with other HPV types or not.

HPV vaccine: Cervarix

IMPORTANCE OF THE FIELD

Cervical cancer is a major cause of morbidity and mortality worldwide and is common in relatively young women. Cervical screening programs, while successful if properly carried out, are difficult and expensive to implement, and offer secondary, not primary prevention. Vaccination against the human papillomavirus (HPV), which is the major cause of cervical cancer, is a significant step forward.

AREAS COVERED IN THIS REVIEW

The data on Cervarix, the GSK HPV vaccine, are reviewed and placed in the context of HPV vaccination as a whole. A literature review using PubMed listed publications and official product websites has been carried out.

WHAT THE READER WILL GAIN

The reader will gain an understanding of the issues involved in HPV vaccination and of the data to date.

TAKE HOME MESSAGE

Cervarix has been shown to have high efficacy against disease associated with both HPV-16 and HPV-18. Its antibody response profile allows for optimism regarding the duration of immunity. The fact that it is a virus-like particle, rather than a live-virus vaccine, is reassuring regarding safety, as are the reasonably extensive safety data for the vaccine preparation so far accrued. Cross protection against oncogenic non-vaccine HPV types, in particular HPV-45, may be important in the prevention of cervical adenocarcinoma, which is currently not well served by screening.

Current prophylactic HPV vaccines and gynecologic premalignancies

PURPOSE OF REVIEW

Studies of the human papillomavirus (HPV) vaccines, Cervarix and Gardasil provide strong evidence for the recommendation that HPV vaccines may minimize the incidence of cervical cancer over time.

RECENT FINDINGS

Both Cervarix and Gardasil provided more than 90% efficacy in preventing cervical intraepithelial neoplasia grade 2+ (CIN 2+) disease caused by HPV 16 and 18 in women 16-26 years who were seronegative and PCR-negative for HPV 16 and 18 at baseline. Cervarix provides more than 75% efficacy in independent cross-protection against persistent HPV 31 and 45, and 47% efficacy against HPV 33; whereas Gardasil offers 50% efficacy only against persistent HPV 31. A reduction in excisional therapies for CIN 2+ is nearly 70% for Cervarix, and 40% for Gardasil. Cervarix efficacy is documented to 6.4 years; Gardasil's to 5 years. Immunologically, Cervarix induces three to nine-fold higher peak-neutralizing antibody titers to HPV 16/18 than Gardasil, has significantly higher cervicovaginal mucus-neutralizing antibody presence than Gardasil, and significantly higher B memory cell response than Gardasil. Safety reports indicate injection site reactions for both Cervarix and Gardasil. Rare serious adverse events have been reported.