The impact of quadrivalent human papillomavirus (HPV; types 6, 11, 16, and 18) L1 virus-like particle vaccine on infection and disease due to oncogenic nonvaccine HPV types in sexually active women aged 16-26 years

Clinical effectiveness and cost-effectiveness of interventions for the treatment of anogenital warts: systematic review and economic evaluation

BACKGROUND

Typically occurring on the external genitalia, anogenital warts (AGWs) are benign epithelial skin lesions caused by human papillomavirus infection. AGWs are usually painless but can be unsightly and physically uncomfortable, and affected people might experience psychological distress. The evidence base on the clinical effectiveness and cost-effectiveness of treatments for AGWs is limited.

OBJECTIVES

To systematically review the evidence on the clinical effectiveness of medical and surgical treatments for AGWs and to develop an economic model to estimate the cost-effectiveness of the treatments.

DATA SOURCES

Electronic databases (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Web of Science) were searched from inception (or January 2000 for Web of Science) to September 2014. Bibliographies of relevant systematic reviews were hand-searched to identify potentially relevant studies. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were searched for ongoing and planned studies.

REVIEW METHODS

A systematic review of the clinical effectiveness literature was carried out according to standard methods and a mixed-treatment comparison (MTC) undertaken. The model implemented for each outcome was that with the lowest deviance information criterion. A de novo economic model was developed to assess cost-effectiveness from the perspective of the UK NHS. The model structure was informed through a systematic review of the economic literature and in consultation with clinical experts. Effectiveness data were obtained from the MTC. Costs were obtained from the literature and standard UK sources.

RESULTS

Of 4232 titles and abstracts screened for inclusion in the review of clinical effectiveness, 60 randomised controlled trials (RCTs) evaluating 19 interventions were included. Analysis by MTC indicated that ablative techniques were typically more effective than topical interventions at completely clearing AGWs at the end of treatment. Podophyllotoxin 0.5% solution (Condyline(®), Takeda Pharmaceutical Company Ltd; Warticon(®) solution, Stiefel Laboratories Ltd) was found to be the most effective topical treatment evaluated. Networks for other outcomes included fewer treatments, which restrict conclusions on the comparative effectiveness of interventions. In total, 84 treatment strategies were assessed using the economic model. Podophyllotoxin 0.5% solution first line followed by carbon dioxide (CO2) laser therapy second line if AGWs did not clear was most likely to be considered a cost-effective use of resources at a willingness to pay of £20,000-30,000 per additional quality-adjusted life-year gained. The result was robust to most sensitivity analyses conducted.

LIMITATIONS

Limited reporting in identified studies of baseline characteristics for the enrolled population generates uncertainty around the comparability of the study populations and therefore the generalisability of the results to clinical practice. Subgroup analyses were planned based on type, number and size of AGWs, all of which are factors thought to influence treatment effect. Lack of data on clinical effectiveness based on these characteristics precluded analysis of the differential effects of treatments in the subgroups of interest. Despite identification of 60 studies, most comparisons in the MTC are informed by only one RCT. Additionally, lack of head-to-head RCTs comparing key treatments, together with minimal reporting of results in some studies, precluded comprehensive analysis of all treatments for AGWs.

CONCLUSIONS

The results generated by the MTC are in agreement with consensus opinion that ablative techniques are clinically more effective at completely clearing AGWs after treatment. However, the evidence base informing the MTC is limited. A head-to-head RCT that evaluates the comparative effectiveness of interventions used in clinical practice would help to discern the potential advantages and disadvantages of the individual treatments. The results of the economic analysis suggest that podophyllotoxin 0.5% solution is likely to represent a cost-effective first-line treatment option. More expensive effective treatments, such as CO2 laser therapy or surgery, may represent cost-effective second-line treatment options. No treatment and podophyllin are unlikely to be considered cost-effective treatment options. There is uncertainty around the cost-effectiveness of treatment with imiquimod, trichloroacetic acid and cryotherapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005457.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Factors Associated with HPV Vaccination among Cambodian American Teenagers

OBJECTIVES

Parents have general influence over their children's health and health behavior. However, given the dearth of specific literature regarding knowledge level and social and cultural factors influencing HPV vaccination behaviors among Cambodian American (CA) parent, it is difficult to develop an effective, evidence-based public health HPV vaccination program. Therefore, the objectives of this study were to determine the HPV vaccine uptakes among CA teenagers and to examine factors influencing HPV vaccine uptakes.

DESIGN AND SAMPLE

A descriptive, cross-sectional survey design and a combination of network and targeted sampling methods were used.

RESULTS

CA mothers (n = 130) completed a health survey through face-to-face interviews in either English or Khmer language. Girls vaccination rates were 29% while that of boys was 16%. Awareness and knowledge of HPV among CA mothers was very low, and many believed that their daughters, who speak English and were educated in the U.S., had more knowledge about health than they did. Logistic regression analysis showed that CA girls had significantly higher odds of vaccination when their mothers possessed a higher level of English reading ability and had greater awareness and knowledge of HPV.

CONCLUSIONS

The strikingly low rates of HPV vaccination among CA girls and boys underscore the need to improve vaccination outreach, education, and uptake. The findings can be used to develop targeted public health HPV vaccination programs for CAs, which will reduce cervical cancer disparities.

Prevalence of human papillomavirus infection among women presenting for cervical cancer screening in Chile, 2014-2015

Cervical cancer is the fourth most common malignancy in women worldwide. In Chile, cervical cancer is the second leading cause of death among women of reproductive age, causing more than 600 deaths annually. This study was carried out to determine the burden and confirm the predominant human papillomavirus (HPV) genotypes among women presenting for cervical cancer screening in public health services in Chile. Women aged 18-64 years residing in the north and central areas covered by six primary care centers of Santiago, Chile, were invited to participate from March 2014 to August 2015. Cervical swabs were examined both HPV genotyping by PCR and Reverse Line Blot, and cervical cytology by Pap testing. A total of 1738 women were included in this study: 11.1 % were HPV positive, 9.7 % were high-risk types positive, 3.2 % were low-risk types positive, 1.4 % were Pap positive and 0.9 % were positive by both tests. The four most predominant genotypes were 16, 66, 51 and 59, with prevalence of 2.8, 1.4, 1.2 and 1.2 %, respectively. Multiple HPV infections were detected among 3.8 % participants. Age-specific prevalence of HPV showed a peak in HPV infection at younger ages (≤30 years), declining to a plateau in middle age. Among women with normal cytology, the 9.4 % were HPV positive, while 58.3 % of women with abnormal cytology were HPV positive. These findings show new epidemiological data confirming HPV 16 and 66 as the most predominant genotypes in Chile. These data are important for design successful strategies for prevention of cervical cancer in Chile.

Urine testing to monitor the impact of HPV vaccination in Bhutan and Rwanda

Bhutan (2010) and Rwanda (2011) were the first countries in Asia and Africa to introduce national, primarily school-based, human papillomavirus (HPV) vaccination programmes. These target 12 year-old girls and initially included catch-up campaigns (13-18 year-olds in Bhutan and ninth school grade in Rwanda). In 2013, to obtain the earliest indicators of vaccine effectiveness, we performed two school-based HPV urine surveys; 973 female students (median age: 19 years, 5th-95th percentile: 18-22) were recruited in Bhutan and 912 (19 years, 17-20) in Rwanda. Participants self-collected a first-void urine sample using a validated protocol. HPV prevalence was obtained using two PCR assays that differ in sensitivity and type spectrum, namely GP5+/GP6+ and E7-MPG. 92% students in Bhutan and 43% in Rwanda reported to have been vaccinated (median vaccination age = 16, 5th-95th: 14-18). HPV positivity in urine was significantly associated with sexual activity measures. In Rwanda, HPV6/11/16/18 prevalence was lower in vaccinated than in unvaccinated students (prevalence ratio, PR = 0.12, 95% confidence interval, CI: 0.03-0.51 by GP5+/GP6+, and 0.45, CI: 0.23-0.90 by E7-MPG). For E7-MPG, cross-protection against 10 high-risk types phylogenetically related to HPV16 or 18 was of borderline significance (PR = 0.68; 95% CI: 0.45-1.01). In Bhutan, HPV6/11/16/18 prevalence by GP5+/GP6+ was lower in vaccinated than in unvaccinated students but CIs were broad. In conclusion, our study supports the feasibility of urine surveys to monitor HPV vaccination and quantifies the effectiveness of the quadrivalent vaccine in women vaccinated after pre-adolescence. Future similar surveys should detect increases in vaccine effectiveness if vaccination of 12 year-olds continues.

Virus-based nanoparticles as platform technologies for modern vaccines

Nanoscale engineering is revolutionizing the development of vaccines and immunotherapies. Viruses have played a key role in this field because they can function as prefabricated nanoscaffolds with unique properties that are easy to modify. Viruses are immunogenic via multiple pathways, and antigens displayed naturally or by engineering on the surface can be used to create vaccines against the cognate virus, other pathogens, specific molecules or cellular targets such as tumors. This review focuses on the development of virus-based nanoparticle systems as vaccines indicated for the prevention or treatment of infectious diseases, chronic diseases, cancer, and addiction. WIREs Nanomed Nanobiotechnol 2016, 8:554-578. doi: 10.1002/wnan.1383 For further resources related to this article, please visit the WIREs website.

Comparison of HPV prevalence between HPV-vaccinated and non-vaccinated young adult women (20-26 years)

There is some concern about the effectiveness of the HPV vaccine among young adult women due to the risk of prior HPV infection. This study used National Health and Nutrition Examination Survey (NHANES) 2007-2012 data to evaluate the effectiveness of HPV vaccination among women 20-26 years of age who were vaccinated after 12 years of age. This cross-sectional study examined 878 young adult women (20-26 years) with complete information on HPV prevalence and HPV vaccination status from NHANES 2007-2012. Vaginal swab specimens were analyzed for HPV DNA by L1 consensus polymerase chain reaction followed by type-specific hybridization. Multivariate logistic regression models controlling for sociodemographic characteristics and sexual behaviors were used to compare type-specific HPV prevalence between vaccinated and unvaccinated women. A total of 21.4% of young adult women surveyed through NHANES between 2007 and 2012 received the HPV vaccine. Vaccinated women had a lower prevalence of vaccine types than unvaccinated women (7.4% vs 17.1%, prevalence ratio 0.43, 95% CI 0.21-0.88). The prevalence of high-risk nonvaccine types was higher among vaccinated women than unvaccinated women (52.1% vs 40.4%, prevalence ratio 1.29, 95% CI 1.06-1.57), but this difference was attenuated after adjusting for sexual behavior variables (adjusted prevalence ratio 1.19, 95% CI 0.99-1.43). HPV vaccination was effective against all 4 vaccine types in young women vaccinated after age 12. However, vaccinated women had a higher prevalence of high-risk nonvaccine types, suggesting that they may benefit from newer vaccines covering additional types.

Impact of 2-, 4- and 9-valent HPV vaccines on morbidity and mortality from cervical cancer

Cervical cancer causes significant morbidity and mortality worldwide. Most cervical cancers are associated with oncogenic human papillomavirus (HPV), and vaccination with any of 3 available HPV vaccines is anticipated to greatly reduce the burden of cervical cancer. This review provides an overview of the burden of HPV, the efficacy and clinical effectiveness of the bivalent (HPV 16, 18), quadrivalent (HPV 6, 11, 16, 18) and 9vHPV (HPV 6, 11, 16, 1831, 33, 45, 52, 58) vaccines in order to assess the anticipated impact on cervical cancer. All three vaccines show high efficacy in prevention of vaccine-specific HPV-type infection and associated high-grade cervical dysplasia in HPV-naïve women. Early clinical effectiveness data for the bivalent and quadrivalent vaccine demonstrate reduced rates of HPV 16 and 18 prevalence in vaccinated cohorts; data evaluating cervical dysplasia and cervical procedures as outcomes will shed further light on the clinical effectiveness of both vaccines. The bivalent vaccine has demonstrated cross-protection to non-vaccine HPV types, including the types in the 9vHPV vaccine. No clinical effectiveness data is yet available for the 9vHPV vaccine.  While HPV vaccination has great promise to reduce cervical cancer morbidity and mortality, estimated benefits are largely theoretical at present. Large population-based clinical effectiveness studies will provide long-term immunogenicity and effectiveness, as well as assessment of cervical cancer as an endpoint, particularly as young vaccinated women enter the appropriate age range to initiate screening for cervical cancer. Strengthening screening and treatment programs will likely have the greatest impact in the short-term on cervical cancer morbidity and mortality.

Development of a Triple-Color Pseudovirion-Based Assay to Detect Neutralizing Antibodies against Human Papillomavirus

Pseudovirion-based neutralization assay is considered the gold standard method for evaluating the immune response to human papillomavirus (HPV) vaccines. In this study, we developed a multicolor neutralization assay to simultaneously detect the neutralizing antibodies against different HPV types. FluoroSpot was used to interpret the fluorescent protein expression instead of flow cytometry. The results of FluoroSpot and flow cytometry showed good consistency, with R² > 0.98 for the log-transformed IC₅₀ values. Regardless of the reporter color, the single-, dual-, and triple-color neutralization assays reported identical results for the same samples. In low-titer samples from naturally HPV-infected individuals, there was strong agreement between the single- and triple-color assays, with kappa scores of 0.92, 0.89, and 0.96 for HPV16, HPV18, and HPV58, respectively. Good reproducibility was observed for the triple-color assay, with coefficients of variation of 2.0%–41.5% within the assays and 8.3%–36.2% between the assays. Three triple-color systems, HPV16-18-58, HPV6-33-45, and HPV11-31-52, were developed that could evaluate the immunogenicity of a nonavalent vaccine in three rounds of the assay. With the advantages of an easy-to-use procedure and less sample consumption, the multiple-color assay is more suitable than classical assays for large sero-epidemiological studies and clinical trials and is more amenable to automation.

Gardasil-9: A global survey of projected efficacy

Human papillomaviruses (HPVs) are the causative agents of human neoplasias such as warts and cancers. There are ∼19 HPV types associated with cancers, which has made it very challenging for first generation HPV vaccines to offer complete protection against all cancer-causing HPV types. Recently, a second generation HPV vaccine, Gardasil-9, has been approved to protect against more HPV types. Worldwide, Gardasil-9 will protect against HPV types associated with ∼90% of cervical cancer case in women and 80-95% of other HPV-associated anogenital cancers in both men and women. However, due to variation in HPV-type specific prevalence and distribution, the vaccine will offer different percentages of protection in different geographical regions; Gardasil-9 will offer protection against HPV types associated with ∼87.7% of cervical cancers in Asia, 91.7% in Africa, 92% in North America, 90.9% in Europe, 89.5% in Latin America & the Caribbean, and 86.5% in Australia. Because of this, Pap smear screening and testing for HPV types not included in Gardasil-9 will need to continue, especially in HIV/AIDS patients. In order to achieve complete protection against all HPV types that cause cervical cancer, a third-generation HPV vaccine is needed.

Prevalence of HPV After Introduction of the Vaccination Program in the United States

BACKGROUND

Since mid-2006, human papillomavirus (HPV) vaccination has been recommended for females aged 11 to 12 years and through 26 years if not previously vaccinated.

METHODS

HPV DNA prevalence was analyzed in cervicovaginal specimens from females aged 14 to 34 years in NHANES in the prevaccine era (2003-2006) and 4 years of the vaccine era (2009-2012) according to age group. Prevalence of quadrivalent HPV vaccine (4vHPV) types (HPV-6, -11, -16, and -18) and other HPV type categories were compared between eras. Prevalence among sexually active females aged 14 to 24 years was also analyzed according to vaccination history.

RESULTS

Between the prevacccine and vaccine eras, 4vHPV type prevalence declined from 11.5% to 4.3% (adjusted prevalence ratio [aPR]: 0.36 [95% confidence interval (CI): 0.21-0.61]) among females aged 14 to 19 years and from 18.5% to 12.1% (aPR: 0.66 [95% CI: 0.47-0.93]) among females aged 20 to 24 years. There was no decrease in 4vHPV type prevalence in older age groups. Within the vaccine era, among sexually active females aged 14 to 24 years, 4vHPV type prevalence was lower in vaccinated (≥1 dose) compared with unvaccinated females: 2.1% vs 16.9% (aPR: 0.11 [95% CI: 0.05-0.24]). There were no statistically significant changes in other HPV type categories that indicate cross-protection.

CONCLUSIONS

Within 6 years of vaccine introduction, there was a 64% decrease in 4vHPV type prevalence among females aged 14 to 19 years and a 34% decrease among those aged 20 to 24 years. This finding extends previous observations of population impact in the United States and demonstrates the first national evidence of impact among females in their 20s.

Morbidity and mortality of vulvar and vaginal cancers: Impact of 2-, 4-, and 9-valent HPV vaccines

Vaginal and vulvar cancers do not account for a large proportion of gynecologic malignancies but their impact is significant. Both vaginal and vulvar lesions have precursors and display levels of dysplasia before progression to invasive disease. Human Papillomavirus (HPV) is a known causative agent of such dysplasia and can be detected now more readily than ever with adequate recognition techniques and provider awareness. Although HPV vaccination is still lagging compared to other recommended childhood vaccinations, the impact on lower genital tract neoplasia is promising. The bivalent and quadrivalent vaccines have been shown to be efficacious and the newest nonavalent vaccine should add even more of impact on coverage of cancer-causing HPV types. Although it is still early to show true clinical and population-based disease reduction due to low disease incidence and relatively short time of vaccine availability, the potential is noteworthy.

Clinical cancer chemoprevention: From the hepatitis B virus (HBV) vaccine to the human papillomavirus (HPV) vaccine

Approximately 2 million new cancer cases are attributed to infectious agents each year worldwide. Vaccines for the hepatitis B virus (HBV), a risk factor of hepatocellular cancer, and human papillomavirus (HPV), a risk factor of cervical cancer, are considered major successes in clinical chemoprevention of cancer. In Taiwan, the first evidence of cancer prevention through vaccinations was provided by HBV vaccination data in infants. The Taiwanese HBV vaccination program has since become a model immunization schedule for newborns worldwide. Persistent infection with high-risk HPV is generally accepted as prerequisite for cervical cancer diagnosis; however, cervical cancer is a rare complication of HPV infections. This is due to the fact that such infections tend to be transient. The safety and efficacy of both available HPV quadrivalent vaccine and bivalent vaccine are not in doubt at the present time. Until a human cytomegalovirus (CMV) vaccine becomes available, simple hygienic practices, such as hand washing, can prevent CMV infection both before and during pregnancy. Each country should establish her official guidelines regarding which vaccines should be used to treat various conditions, the target population (i.e., universal or limited to a selected population), and the immunization schedules. After a vaccine is recommended, decisions regarding reimbursement by the public health care fund are evaluated. The guidelines become part of the immunization schedule, which is updated annually and published in the official bulletin. In conclusion, both HBV and HPV vaccines are considered major successes in the chemoprevention of cancer.

Deconstructing the measure of vaccine efficacy against disease irrespective of HPV in HPV vaccine clinical trials

BACKGROUND

Human papillomavirus (HPV) vaccines were licensed by demonstrating prevention of anogenital disease caused by specific HPV types in clinical studies. Measuring the impact of HPV vaccination on the overall burden of anogenital disease (irrespective of HPV) is an important public health question which is ideally addressed in post-licensure epidemiological studies. Attempts were made to use clinical trial data for that purpose. However, the interpretation of vaccine efficacy on the endpoint of disease irrespective of HPV is not widely understood.

METHODS

We used the 9-valent HPV vaccine clinical program as a case study to determine the value of measuring vaccine efficacy in such endpoint. This assessment was rigorously performed by heuristic reasoning and through probability calculations.

RESULTS

The measure of vaccine efficacy in the irrespective of HPV endpoint is driven simultaneously in opposite directions by the high estimate of prophylactic efficacy and a numerically negative estimate of risk reduction that is also a reflection of high prophylactic efficacy and no cross-protection.

CONCLUSIONS

The vaccine efficacy estimate in the irrespective of HPV endpoint is ambiguous and difficult to interpret. Comparing this estimate across different HPV vaccine studies requires an understanding of the contributions of vaccine HPV type efficacy and the incidence of disease not related to vaccine HPV types for each study. Without such understanding, comparing studies and drawing conclusions from such comparison are highly misleading. Approaches are proposed to divide this endpoint in components that are easier to interpret.

Cost-Effectiveness Analysis of Universal Human Papillomavirus Vaccination Using a Dynamic Bayesian Methodology: The BEST II Study

BACKGROUND

Human papillomavirus (HPV) plays a role in the development of benign and malign neoplasms in both sexes. The Italian recommendations for HPV vaccines consider only females. The BEST II study (Bayesian modelling to assess the Effectiveness of a vaccination Strategy to prevent HPV-related diseases) evaluates 1) the cost-effectiveness of immunization strategies targeting universal vaccination compared with cervical cancer screening and female-only vaccination and 2) the economic impact of immunization on various HPV-induced diseases.

OBJECTIVE

The objective of this study was to evaluate whether female-only vaccination or universal vaccination is the most cost-effective intervention against HPV.

METHODS

We present a dynamic Bayesian Markov model to investigate transmission dynamics in cohorts of females and males in a follow-up period of 55 years. We assumed that quadrivalent vaccination (against HPV 16, 18, 6, and 11) is available for 12-year-old individuals. The model accounts for the progression of subjects across HPV-induced health states (cervical, vaginal, vulvar, anal, penile, and head/neck cancer as well as anogenital warts). The sexual mixing is modeled on the basis of age-, sex-, and sexual behavioral-specific matrices to obtain the dynamic force of infection.

RESULTS

In comparison to cervical cancer screening, universal vaccination results in an incremental cost-effectiveness ratio of €1,500. When universal immunization is compared with female-only vaccination, it is cost-effective with an incremental cost-effectiveness ratio of €11,600. Probabilistic sensitivity analysis shows a relatively large amount of parameter uncertainty, which interestingly has, however, no substantial impact on the decision-making process. The intervention being assessed seems to be associated with an attractive cost-effectiveness profile.

CONCLUSIONS

Universal HPV vaccination is found to be a cost-effective choice when compared with either cervical cancer screening or female-only vaccination within the Italian context.

European Code against Cancer 4th Edition: Infections and Cancer

Of the 2,635,000 new cancer cases (excluding non-melanoma skin cancers) occurring in the European Union (EU) in 2012, it is estimated that approximately 185,000 are related to infection with human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV), and Helicobacter pylori (H. pylori). Chronic infection with these agents can lead to cancers of the cervix uteri, liver, and stomach, respectively. Chronic infection with HCV can also lead to B-cell non-Hodgkin lymphoma. Human immunodeficiency virus (HIV) infection continues to be of major public health importance in several EU countries and increases cancer risk via HIV-induced immunosuppression. The fourth edition of the European Code Against Cancer presents recommendations on effective and safe preventive interventions in order to reduce the risk of infection-related cancers in EU citizens. Based on current available evidence, the fourth edition recommends that parents ensure the participation of their children in vaccination programs against HBV (for newborns) and HPV (for girls). In the 'Questions and Answers' (Q&As) section about vaccination and infections in the website for the European Code Against Cancer, individuals who are at risk of chronic HBV or HCV are advised to seek medical advice about testing and obtaining treatment when appropriate. Individuals most at risk of HIV are advised to consult their doctor or healthcare provider to access counselling and, if needed, testing and treatment without delay. Information about H. pylori testing and treatment is also provided as testing might currently be offered in some high-risk areas in Europe. The rationale and supporting evidence for the recommendations on vaccination in the European Code Against Cancer, and for the main recommendations on vaccination and infection in the Q&As, are explained in the present review.

Delivery strategies to enhance oral vaccination against enteric infections

While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases.

Prevalence of type-specific HPV among female university students from northern Brazil

Background

Human papillomavirus (HPV) infection is associated with cervical cancer, the most frequent cancer in women from northern Brazil. Assessment of the short-term impact of HPV vaccination depends on the availability of data on the prevalence of type-specific HPV in young women in the pre-immunization period, although these data are currently unavailable for the study region. The aim of this study was to estimate the distribution of all mucosal HPV genotypes, including low- and high-risk HPV types, in unvaccinated college students from northern Brazil.

Findings

Specimens were collected from 265 university students during routine cervical cancer screening. The HPV DNA was assessed by Polymerase Chain Reaction and positive samples were genotyped by Restriction Fragment Length Polymorphism. Most students (85.7 %) had normal cytological results. The prevalence of HPV was 25.3 % (67/265), with a high frequency of multiple infections and non-vaccine high-risk HPV genotypes. The most prevalent type was HPV-61 (5.3 %), followed by types 82, 16, 59, and 6. Multiple infections were associated with high-risk and possibly high-risk HPVs.

Conclusions

We demonstrated a high prevalence of HPV infection in university students from northern Brazil. Vaccine high-risk types were relatively rare, emphasizing the predominance of carcinogenic genotypes that are not prevented by the currently available vaccines. Our study highlights the need to reinforce cytological screening in women from northern Brazil, and promote the early diagnosis and treatment of the precancerous lesions associated with cervical cancer.

Human papillomavirus in young women with Chlamydia trachomatis infection 7 years after the Australian human papillomavirus vaccination programme: a cross-sectional study

BACKGROUND

The national quadrivalent human papillomavirus (4vHPV) vaccination programme was launched in Australia in April, 2007. In this study, we aimed to explore the prevalence of vaccine-targeted human papillomavirus (HPV) types contained in the 4vHPV and nine-valent HPV (9vHPV) vaccines detected in young women diagnosed with chlamydia.

METHODS

In this cross-sectional study, we identified specimens from women aged 25 years or younger who attended the Melbourne Sexual Health Centre (Melbourne, VIC, Australia) diagnosed with chlamydia. We calculated the prevalence of 4vHPV types (6, 11, 16, and 18) and the extra five 9vHPV types (31, 33, 45, 52, and 58 alone) excluding 4vHPV types, stratified by Australian financial year (and according to the prevaccination and postvaccination periods) and self-reported vaccination status, for all women, Australian-born women, Australian-born women aged 21 years and younger, and overseas-born women. We calculated adjusted prevalence ratios using binomial log linear regression.

FINDINGS

Between July 1, 2004, and June 30, 2014, we included 1202 women. The prevalence of 4vHPV types in Australian-born women decreased during this period (HPV 6 and 11: 2004-05 nine [16%, 95% CI 8-28] of 56 vs 2013-14 one [2%, 0-9] of 57, p<0·0001; HPV 16 and 18: 17 [30%, 19-44] vs two [4%, 0-12], p<0·0001). In Australian-born women aged 21 years and younger, HPV 6 and 11 prevalence remained at 0% for all years after 2008-09, and we detected HPV 16 and 18 in 5% or less of samples for the same period. In unvaccinated Australian-born women, we noted a significant decrease in 4vHPV types from 66 (41%, 95% CI 34-49) of 160 in the prevaccination period (from July 1, 2004, to June 30, 2007) to five (19%, 6-38) of 27 in the postvaccination period (July 1, 2007, to June 30, 2014; p=0·031), but not in the 9vHPV types, excluding 4vHPV (36 [23%, 95% CI 16-30] vs seven [26%, 11-46]; p=0·805).

INTERPRETATION

The three-dose vaccination coverage was sufficient for the 4vHPV types to almost disappear in Australian-born women aged 21 years or younger within 3 years of introduction of the national HPV vaccination programme. We noted strong herd protection, with a significant decrease in the prevalence of 4vHPV in unvaccinated women. The 4vHPV vaccination programme in Australia has been successful at protecting women against 4vHPV types.

FUNDING

Australian National Health and Medical Research Council.

Quadrivalent human papillomavirus (types 6, 11, 16, 18) recombinant vaccine (gardasil(®)): a review of its use in the prevention of premalignant anogenital lesions, cervical and anal cancers, and genital warts

Quadrivalent human papillomavirus (HPV) [types 6, 11, 16, 18] recombinant vaccine (Gardasil(®); Silgard(®)) is composed of virus-like particles formed by self-assembly of recombinant L1 capsid protein from each of HPV types 6, 11, 16 and 18. It is indicated for use from the age of 9 years as a two- or three-dose vaccination course over 6 months for the prevention of premalignant anogenital lesions, cervical and anal cancers, and genital warts caused by the vaccine HPV types. In placebo-controlled trials, quadrivalent HPV vaccine provided high-level protection against infection or disease caused by the vaccine HPV types over 2-4 years in females aged 15-45 years who were negative for the vaccine HPV types, and provided a degree of cross-protection against certain non-vaccine HPV types. The vaccine also provided high-level protection against persistent infection, anogenital precancerous lesions and genital warts caused by the vaccine HPV types over 3 years in susceptible males aged 16-26 years. Protection has been demonstrated for up to 8 years. In subjects who were negative for the vaccine HPV types, high seroconversion rates and high levels of anti-HPV antibodies were observed in females of all age ranges from 9 to 45 years and in males aged 9-26 years. The vaccine was generally well tolerated and was usually predicted to be cost effective in girls and young women. Therefore, quadrivalent HPV vaccine offers an effective means to substantially reduce the burden of HPV-related anogenital disease in females and males, particularly cervical cancer and genital warts.

HPV and Cervical Dysplasia in Adolescents: A Progressive March Toward Prevention

Cervical cancer caused by infection with the human papillomavirus is the second most common malignancy among women worldwide. Over the course of the past century our understanding of the virus and the disease has expanded exponentially through landmark studies and pioneers of academic medicine. It has all led to the current evidence-based guidelines for prevention of cervical dysplasia and invasive carcinoma in adolescent females that will significantly lessen morbidity and mortality and may eradicate the disease completely. Unfortunately, the greatest challenge to this may be overcoming common misunderstandings and other barriers to compliance with these guidelines among practitioners, patients, and the general public.

Preclinical refinements of a broadly protective VLP-based HPV vaccine targeting the minor capsid protein, L2

An ideal prophylactic human papillomavirus (HPV) vaccine would provide broadly protective and long-lasting immune responses against all high-risk HPV types, would be effective after a single dose, and would be formulated in such a manner to allow for long-term storage without the necessity for refrigeration. We have developed candidate HPV vaccines consisting of bacteriophage virus-like particles (VLPs) that display a broadly neutralizing epitope derived from the HPV16 minor capsid protein, L2. Immunization with 16L2 VLPs elicited high titer and broadly cross-reactive and cross-neutralizing antibodies against diverse HPV types. In this study we introduce two refinements for our candidate vaccines, with an eye towards enhancing efficacy and clinical applicability in the developing world. First, we assessed the role of antigen dose and boosting on immunogenicity. Mice immunized with 16L2-MS2 VLPs at doses ranging from 2 to 25 μg with or without alum were highly immunogenic at all doses; alum appeared to have an adjuvant effect at the lowest dose. Although boosting enhanced antibody titers, even a single immunization could elicit strong and long-lasting antibody responses. We also developed a method to enhance vaccine stability. Using a spray dry apparatus and a combination of sugars & an amino acid as protein stabilizers, we generated dry powder vaccine formulations of our L2 VLPs. Spray drying of our L2 VLPs did not affect the integrity or immunogenicity of VLPs upon reconstitution. Spray dried VLPs were stable at room temperature and at 37 °C for over one month and the VLPs were highly immunogenic. Taken together, these enhancements are designed to facilitate implementation of a next-generation VLP-based HPV vaccine which addresses U.S. and global disparities in vaccine affordability and access in rural/remote populations.

Cross-Reactivity, Epitope Spreading, and De Novo Immune Stimulation Are Possible Mechanisms of Cross-Protection of Nonvaccine Human Papillomavirus (HPV) Types in Recipients of HPV Therapeutic Vaccines

Numerous versions of human papillomavirus (HPV) therapeutic vaccines designed to treat individuals with established HPV infection, including those with cervical intraepithelial neoplasia (CIN), are in development because approved prophylactic vaccines are not effective once HPV infection is established. As human papillomavirus 16 (HPV-16) is the most commonly detected type worldwide, all versions of HPV therapeutic vaccines contain HPV-16, and some also contain HPV-18. While these two HPV types are responsible for approximately 70% of cervical cancer cases, there are other high-risk HPV types known to cause malignancy. Therefore, it would be of interest to assess whether these HPV therapeutic vaccines may confer cross-protection against other high-risk HPV types. Data available from a few clinical trials that enrolled subjects with CINs regardless of the HPV type(s) present demonstrated clinical responses, as measured by CIN regression, in subjects with both vaccine-matched and nonvaccine HPV types. The currently available evidence demonstrating cross-reactivity, epitope spreading, and de novo immune stimulation as possible mechanisms of cross-protection conferred by investigational HPV therapeutic vaccines is discussed.

Population-level impact and herd effects following human papillomavirus vaccination programmes: a systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) vaccination programmes were first implemented in several countries worldwide in 2007. We did a systematic review and meta-analysis to assess the population-level consequences and herd effects after female HPV vaccination programmes, to verify whether or not the high efficacy reported in randomised controlled clinical trials are materialising in real-world situations.

METHODS

We searched the Medline and Embase databases (between Jan 1, 2007 and Feb 28, 2014) and conference abstracts for time-trend studies that analysed changes, between the pre-vaccination and post-vaccination periods, in the incidence or prevalence of at least one HPV-related endpoint: HPV infection, anogenital warts, and high-grade cervical lesions. We used random-effects models to derive pooled relative risk (RR) estimates. We stratified all analyses by age and sex. We did subgroup analyses by comparing studies according to vaccine type, vaccination coverage, and years since implementation of the vaccination programme. We assessed heterogeneity across studies using I(2) and χ(2) statistics and we did trends analysis to examine the dose-response association between HPV vaccination coverage and each study effect measure.

FINDINGS

We identified 20 eligible studies, which were all undertaken in nine high-income countries and represent more than 140 million person-years of follow-up. In countries with female vaccination coverage of at least 50%, HPV type 16 and 18 infections decreased significantly between the pre-vaccination and post-vaccination periods by 68% (RR 0·32, 95% CI 0·19-0·52) and anogenital warts decreased significantly by 61% (0·39, 0·22-0·71) in girls 13-19 years of age. Significant reductions were also recorded in HPV types 31, 33, and 45 in this age group of girls (RR 0·72, 95% CI 0·54-0·96), which suggests cross-protection. Additionally, significant reductions in anogenital warts were also reported in boys younger than 20 years of age (0·66 [95% CI 0·47-0·91]) and in women 20-39 years of age (0·68 [95% CI 0·51-0·89]), which suggests herd effects. In countries with female vaccination coverage lower than 50%, significant reductions in HPV types 16 and 18 infection (RR 0·50, 95% CI 0·34-0·74]) and in anogenital warts (0·86 [95% CI 0·79-0·94]) occurred in girls younger than 20 years of age, with no indication of cross-protection or herd effects.

INTERPRETATION

Our results are promising for the long-term population-level effects of HPV vaccination programmes. However, continued monitoring is essential to identify any signals of potential waning efficacy or type-replacement.

FUNDING

The Canadian Institutes of Health Research.

Design of a large outcome trial for a multivalent human papillomavirus L1 virus-like particle vaccine

BACKGROUND

The 9-valent human papillomavirus (HPV) (9vHPV) vaccine targets the four HPV types (6/11/16/18) covered by the licensed quadrivalent HPV (qHPV) vaccine and five additional types (31/33/45/52/58). A large outcome trial of 9vHPV vaccine was conducted.

METHODS

An active control (qHPV vaccine) was used because a placebo is not ethically acceptable. Since qHPV vaccine is (and 9vHPV vaccine was anticipated to be) highly efficacious against HPV 6/11/16/18, low incidence of HPV 6/11/16/18-associated disease was expected. Consequently, an efficacy comparison of 9vHPV versus qHPV vaccine for HPV 6/11/16/18 would have been prohibitively large in size. Moreover, no minimum antibody level predicting protection against infection or disease is defined for HPV vaccination. As an alternative approach, the two vaccines were compared using immunogenicity bridging for HPV 6/11/16/18 and clinical efficacy for HPV 31/33/45/52/58.

RESULTS

The two co-primary objectives were to demonstrate: (1) non-inferior anti-HPV 6/11/16/18 antibody response; and (2) superior efficacy in HPV 31/33/45/52/58-related clinical outcome, for 9vHPV vaccine versus qHPV vaccine. For HPV 6/11/16/18, supportive analyses included a non-inferiority assessment of the percent risk reduction (compared to historical placebo) for 9vHPV versus qHPV vaccine.

CONCLUSIONS

A Phase III study of 9vHPV vaccine was successfully implemented. Experience from this study design may be applicable when developing a multivalent vaccine covering the same serotypes as an existing vaccine plus additional serotypes and there is no immune correlate of protection. Also, this study established that efficacy of a new HPV vaccine may be demonstrated using immunogenicity endpoints, which may open new options in HPV vaccine development.

A 9-valent HPV vaccine against infection and intraepithelial neoplasia in women

BACKGROUND

The investigational 9-valent viruslike particle vaccine against human papillomavirus (HPV) includes the HPV types in the quadrivalent HPV (qHPV) vaccine (6, 11, 16, and 18) and five additional oncogenic types (31, 33, 45, 52, and 58). Here we present the results of a study of the efficacy and immunogenicity of the 9vHPV vaccine in women 16 to 26 years of age.

METHODS

We performed a randomized, international, double-blind, phase 2b-3 study of the 9vHPV vaccine in 14,215 women. Participants received the 9vHPV vaccine or the qHPV vaccine in a series of three intramuscular injections on day 1 and at months 2 and 6. Serum was collected for analysis of antibody responses. Swabs of labial, vulvar, perineal, perianal, endocervical, and ectocervical tissue were obtained and used for HPV DNA testing, and liquid-based cytologic testing (Papanicolaou testing) was performed regularly. Tissue obtained by means of biopsy or as part of definitive therapy (including a loop electrosurgical excision procedure and conization) was tested for HPV.

RESULTS

The rate of high-grade cervical, vulvar, or vaginal disease irrespective of HPV type (i.e., disease caused by HPV types included in the 9vHPV vaccine and those not included) in the modified intention-to-treat population (which included participants with and those without prevalent infection or disease) was 14.0 per 1000 person-years in both vaccine groups. The rate of high-grade cervical, vulvar, or vaginal disease related to HPV-31, 33, 45, 52, and 58 in a prespecified per-protocol efficacy population (susceptible population) was 0.1 per 1000 person-years in the 9vHPV group and 1.6 per 1000 person-years in the qHPV group (efficacy of the 9vHPV vaccine, 96.7%; 95% confidence interval, 80.9 to 99.8). Antibody responses to HPV-6, 11, 16, and 18 were noninferior to those generated by the qHPV vaccine. Adverse events related to injection site were more common in the 9vHPV group than in the qHPV group.

CONCLUSIONS

The 9vHPV vaccine prevented infection and disease related to HPV-31, 33, 45, 52, and 58 in a susceptible population and generated an antibody response to HPV-6, 11, 16, and 18 that was noninferior to that generated by the qHPV vaccine. The 9vHPV vaccine did not prevent infection and disease related to HPV types beyond the nine types covered by the vaccine. (Funded by Merck; ClinicalTrials.gov number, NCT00543543).

Papillomaviruses: Viral evolution, cancer and evolutionary medicine

Papillomaviruses (PVs) are a numerous family of small dsDNA viruses infecting virtually all mammals. PVs cause infections without triggering a strong immune response, and natural infection provides only limited protection against reinfection. Most PVs are part and parcel of the skin microbiota. In some cases, infections by certain PVs take diverse clinical presentations from highly productive self-limited warts to invasive cancers. We propose PVs as an excellent model system to study the evolutionary interactions between the immune system and pathogens causing chronic infections: genotypically, PVs are very diverse, with hundreds of different genotypes infecting skin and mucosa; phenotypically, they display extremely broad gradients and trade-offs between key phenotypic traits, namely productivity, immunogenicity, prevalence, oncogenicity and clinical presentation. Public health interventions have been launched to decrease the burden of PV-associated cancers, including massive vaccination against the most oncogenic human PVs, as well as systematic screening for PV chronic anogenital infections. Anti-PVs vaccines elicit protection against infection, induce cross-protection against closely related viruses and result in herd immunity. However, our knowledge on the ecological and intrapatient dynamics of PV infections remains fragmentary. We still need to understand how the novel anthropogenic selection pressures posed by vaccination and screening will affect viral circulation and epidemiology. We present here an overview of PV evolution and the connection between PV genotypes and the phenotypic, clinical manifestations of the diseases they cause. This differential link between viral evolution and the gradient cancer-warts-asymptomatic infections makes PVs a privileged playground for evolutionary medicine research.

Post hoc analysis of the PATRICIA randomized trial of the efficacy of human papillomavirus type 16 (HPV-16)/HPV-18 AS04-adjuvanted vaccine against incident and persistent infection with nonvaccine oncogenic HPV types using an alternative multiplex type-specific PCR assay for HPV DNA

The efficacy of the human papillomavirus type 16 (HPV-16)/HPV-18 AS04-adjuvanted vaccine against cervical infections with HPV in the Papilloma Trial against Cancer in Young Adults (PATRICIA) was evaluated using a combination of the broad-spectrum L1-based SPF10 PCR-DNA enzyme immunoassay (DEIA)/line probe assay (LiPA25) system with type-specific PCRs for HPV-16 and -18. Broad-spectrum PCR assays may underestimate the presence of HPV genotypes present at relatively low concentrations in multiple infections, due to competition between genotypes. Therefore, samples were retrospectively reanalyzed using a testing algorithm incorporating the SPF10 PCR-DEIA/LiPA25 plus a novel E6-based multiplex type-specific PCR and reverse hybridization assay (MPTS12 RHA), which permits detection of a panel of nine oncogenic HPV genotypes (types 16, 18, 31, 33, 35, 45, 52, 58, and 59). For the vaccine against HPV types 16 and 18, there was no major impact on estimates of vaccine efficacy (VE) for incident or 6-month or 12-month persistent infections when the MPTS12 RHA was included in the testing algorithm versus estimates with the protocol-specified algorithm. However, the alternative testing algorithm showed greater sensitivity than the protocol-specified algorithm for detection of some nonvaccine oncogenic HPV types. More cases were gained in the control group than in the vaccine group, leading to higher point estimates of VE for 6-month and 12-month persistent infections for the nonvaccine oncogenic types included in the MPTS12 RHA assay (types 31, 33, 35, 45, 52, 58, and 59). This post hoc analysis indicates that the per-protocol testing algorithm used in PATRICIA underestimated the VE against some nonvaccine oncogenic HPV types and that the choice of the HPV DNA testing methodology is important for the evaluation of VE in clinical trials. (This study has been registered at ClinicalTrials.gov under registration no. NCT00122681.).

Change in population prevalences of human papillomavirus after initiation of vaccination: the high-throughput HPV monitoring study

BACKGROUND

Organized human papillomavirus (HPV) vaccination was introduced in Sweden in 2012. On-demand vaccination was in effect from 2006 to 2011. We followed the HPV prevalences in Southern Sweden from 2008 to 2013.

METHODS

Consecutive, anonymized samples from the Chlamydia trachomatis screening were analyzed for HPV DNA for two low-risk types and 14 high-risk types using PCR with genotyping using mass spectrometry. We analyzed 44,146 samples in 2008, 5,224 in 2012, and 5,815 in 2013.

RESULTS

Registry-determined HPV vaccination coverages of the population in Southern Sweden increased mainly among 13- to 22-year-old women. Most analyzed samples contained genital swabs from women and the HPV6 prevalence in these samples decreased from 7.0% in 2008 to 4.2% in 2013 [-40.0%; P < 0.0005 (χ(2) test)]. HPV16 decreased from 14.9% to 8.7% (-41.6%; P < 0.0005) and HPV18 decreased from 7.9% to 4.3% (-45.6%; P < 0.0005) among 13- to 22-year-old women. There were only small changes in vaccination coverage among 23- to 40-year-old women. In this age group, HPV18 decreased marginally (-19.6%; P = 0.04) and there were no significant changes for HPV6 or HPV16. Two nonvaccine HPV types (HPV52 and HPV56) were increased among 13- to 22-year-old women, both in 2012 and 2013.

CONCLUSIONS

A major reduction of HPV6, 16, and 18 prevalences is seen in the age groups with a concomitant increase in HPV vaccination coverage. The minor changes seen for nonvaccine types will require further investigation.

IMPACT

Monitoring of type-specific HPV prevalences may detect early effects of HPV vaccination.

Update on prevention and screening of cervical cancer

Cervical cancer is the third most common cause of cancer in women in the world. During the past few decades tremendous strides have been made toward decreasing the incidence and mortality of cervical cancer with the implementation of various prevention and screening strategies. The causative agent linked to cervical cancer development and its precursors is the human papillomavirus (HPV). Prevention and screening measures for cervical cancer are paramount because the ability to identify and treat the illness at its premature stage often disrupts the process of neoplasia. Cervical carcinogenesis can be the result of infections from multiple high-risk HPV types that act synergistically. This imposes a level of complexity to identifying and vaccinating against the actual causative agent. Additionally, most HPV infections spontaneously clear. Therefore, screening strategies should optimally weigh the benefits and risks of screening to avoid the discovery and needless treatment of transient HPV infections. This article provides an update of the preventative and screening methods for cervical cancer, mainly HPV vaccination, screening with Pap smear cytology, and HPV testing. It also provides a discussion of the newest United States 2012 guidelines for cervical cancer screening, which changed the age to begin and end screening and lengthened the screening intervals.

Meta-analysis on prevalence and attribution of human papillomavirus types 52 and 58 in cervical neoplasia worldwide

Objective

To estimate the prevalence and attribution of two non-vaccine-covered HPV types (HPV52 and HPV58) across the world.

Methods

Meta-analysis on studies reported in English and Chinese between 1994 and 2012.

Results

The pooled prevalence and attribution rates of HPV52 and HPV58 in invasive cervical cancers were significantly higher in Eastern Asia compared to other regions (HPV52 prevalence: 5.7% vs. 1.8–3.6%, P<0.001; HPV52 attribution: 3.7% vs. 0.2–2.0%; HPV58 prevalence: 9.8% vs. 1.1–2.5%, P<0.001; HPV58 attribution: 6.4% vs. 0.7–2.2%, P<0.001). Oceania has an insufficient number of studies to ascertain the prevalence of HPV52. Within Eastern Asia, the attribution of HPV58 to invasive cervical cancer was 1.8-fold higher than that of HPV52. Similarly, HPV52 and HPV58 shared a higher prevalence and attribution among cervical intraepithelial neoplasia in Eastern Asia. In contrast to the classical high-risk type, HPV16, the prevalence and attribution of HPV52 and HPV58 decreased with increasing lesion severity. Thus, HPV52 and HPV58 behave as an “intermediate-risk” type.

Conclusion

The attribution of HPV52 and HPV58 to cervical intraepithelial neoplasia and invasive cancer in Eastern Asia were respectively 2.5–2.8 and 3.7–4.9 folds higher than elsewhere. Changes in the attributed disease fraction can serve as a surrogate marker for cross-protection or type replacement following widespread use of HPV16/18-based vaccines. This unique epidemiology should be considered when designing HPV screening assays and vaccines for Eastern Asia.

HPV in HIV-Infected Women: Implications for Primary Prevention

Background: There is growing evidence that human immunodeficiency virus (HIV)-infected women might have a different human papillomavirus (HPV) type distribution in cervical dysplasia specimens as compared to the general population. This has implications for primary prevention.

Objective: We aimed to obtain preliminary data on the HPV genotypes prevalent in histological samples of HIV-infected women with cervical intraepithelial neoplasia (CIN) 3/CIS of the cervix in Miami, FL, USA.

Methods: Retrospective data were collected on HIV-infected women referred to the University of Miami-Jackson Memorial Hospital colposcopy clinic between years 2000 and 2008. The histology slides of CIN 3/CIS biopsies underwent pathological review and sections were cut from these archived specimens for HPV DNA extraction. HPV genotyping was then performed using the GeneSquare™ HPV genotyping assay. We report on our first set of 23 samples.

Results: Eight high-risk HPV types were detected. Types in decreasing order of frequency were 16, 35, 45, 52, 59, 31, 58, and 56. Most cases had multiple infections. HPV type 16 was the most common (45%) followed by HPV-35 and -45 with equal frequency (40%). No samples contained HPV-18.

Conclusion: Our preliminary results suggest that cervical dysplasia specimens of HIV-infected women more likely (55%) contain non-16 and -18 high-risk HPV types. We show that this held true for histologically confirmed severe dysplasia and carcinoma-in situ. Epidemiological studies guide vaccine development, therefore HPV type prevalence in CIS and invasive cervical cancer among HIV-infected women should be more rigorously explored to ensure that this highly vulnerable population receives appropriate primary prevention.

Human papillomavirus genotype prevalence in invasive vaginal cancer from a registry-based population

OBJECTIVE

To describe the human papillomavirus (HPV) genotype distribution in invasive vaginal cancers diagnosed before the introduction of the HPV vaccine and evaluate if survival differed by HPV status.

METHODS

Four population-based registries and three residual tissue repositories provided formalin-fixed, paraffin-embedded tissue from microscopically confirmed primary vaginal cancer cases diagnosed between 1994 and 2005 that were tested by L1 consensus polymerase chain reaction with type-specific hybridization in a central laboratory. Clinical, demographic, and all-cause survival data were assessed by HPV status.

RESULTS

Sixty cases of invasive vaginal cancer were included. Human papillomavirus was detected in 75% (45) and 25% (15) were HPV-negative. HPV 16 was most frequently detected (55% [33/60]) followed by HPV 33 (18.3% [11/60]). Only one case was positive for HPV 18 (1.7%) Multiple types were detected in 15% of the cases. Vaginal cancers in women younger than 60 years were more likely to be HPV 16- or HPV 18-positive (HPV 16 and 18) than older women, 77.3% compared with 44.7% (P=.038). The median age at diagnosis was younger in the HPV 16 and 18 (59 years) group compared with other HPV-positive (68 years) and no HPV (77 years) (P=.003). The HPV distribution did not significantly vary by race or ethnicity or place of residence. The 5-year unadjusted all-cause survival was 57.4% for women with HPV-positive vaginal cancers compared with 35.7% among those with HPV-negative tumors (P=.243).

CONCLUSION

Three fourths of all vaginal cancers in the United States had HPV detected, much higher than previously found, and 57% could be prevented by current HPV vaccines.

Development of reference materials to detect 15 different human papillomavirus genotypes

Accurate human papillomavirus (HPV) typing is essential for evaluating and monitoring HPV vaccines in cervical cancer screening and in epidemiological surveys. In our country, different HPV DNA detection and genotyping methodologies have been established for diagnosing and monitoring HPV-related disease in clinical practice and for research. However, there is a lack of reference materials to standardize the methods for HPV detection and genotyping. In this study, we constructed candidate reference materials comprising 15 targets (13 types of high-risk HPV, two types of low-risk HPV). We evaluated whether the candidate reference materials could be used as the reference for HPV detection and genotyping using quantitative real-time polymerase chain reaction. Standard curves for the wide linear range (10(1)-10(6)copies/μL) produced high correlation regression coefficient R(2) of 0.99. The reaction efficiencies were 96.3% to 101.2% for the standard curves, indicating highly efficient reactions. Specific genotypes were detected in single or multiple mixed samples. Our results suggest that these reference materials may provide useful standards for standardizing quality assurance for different HPV-typing assays and for proficiency testing in diagnostic laboratories.

Mind the gaps: what's missing from current economic evaluations of universal HPV vaccination?

BACKGROUND

Since the original licensing of human papilloma virus (HPV) vaccination for women, evidence is accumulating of its effectiveness in preventing HPV-related conditions in men, and universal vaccination (vaccinating men and women) is now recommended in some countries. Several models of the cost-effectiveness of universal HPV vaccination have been published, but results have been mixed. This article assesses the extent to which economic studies have captured the range of values associated with universal HPV vaccination, and how this influences estimates of its cost-effectiveness.

METHODS

Eight published economic evaluations of universal HPV vaccination were reviewed to identify which of the values associated with universal HPV vaccination were included in each analysis.

RESULTS

Studies of the cost-effectiveness of universal HPV vaccination capture only a fraction of the values generated. Most studies focused on impacts on health and health system cost, and only captured these partially. A range of values is excluded from most studies, including impacts on productivity, patient time and costs, carers and family costs, and broader social values such as the right to access treatment. Further, those studies that attempted to capture these values only did so partially.

DISCUSSION

Decisions to invest in universal HPV vaccination need to be based on a complete assessment of the value that it generates. This is not provided by existing economic evaluations. Further work is required to understand this value. First, research is required to understand how HPV-related health outcomes impact on society including, for instance, their impact on productivity. Second, consideration should be given to alternative approaches to capture this broader set of values in a manner useful to decisions-makers, such as multi-criteria decision analysis.

A vaccine of L2 epitope repeats fused with a modified IgG1 Fc induced cross-neutralizing antibodies and protective immunity against divergent human papillomavirus types

Current human papillomavirus (HPV) major capsid protein L1 virus-like particles (VLPs)-based vaccines in clinic induce strong HPV type-specific neutralizing antibody responses. To develop pan-HPV vaccines, here, we show that the fusion protein E3R4 consisting of three repeats of HPV16 L2 aa 17–36 epitope (E3) and a modified human IgG1 Fc scaffold (R4) induces cross-neutralizing antibodies and protective immunity against divergent HPV types. E3R4 was expressed as a secreted protein in baculovirus expression system and could be simply purified by one step Protein A affinity chromatography with the purity above 90%. Vaccination of E3R4 formulated with Freunds adjuvant not only induced cross-neutralizing antibodies against HPV pseudovirus types 16, 18, 45, 52, 58, 6, 11 and 5 in mice, but also protected mice against vaginal challenges with HPV pseudovirus types 16, 45, 52, 58, 11 and 5 for at least eleven months after the first immunization. Moreover, vaccination of E3R4 formulated with FDA approved adjuvant alum plus monophosphoryl lipid A also induced cross-neutralizing antibodies against HPV types 16, 18 and 6 in rabbits. Thus, our results demonstrate that delivery of L2 antigen as a modified Fc-fusion protein may facilitate pan-HPV vaccine development.

Effects of varying antigens and adjuvant systems on the immunogenicity and safety of investigational tetravalent human oncogenic papillomavirus vaccines: results from two randomized trials

BACKGROUND

A prophylactic human papillomavirus (HPV) vaccine targeting oncogenic HPV types in addition to HPV-16 and -18 may broaden protection against cervical cancer. Two Phase I/II, randomized, controlled studies were conducted to compare the immunogenicity and safety of investigational tetravalent HPV L1 virus-like particle (VLP) vaccines, containing VLPs from two additional oncogenic genotypes, with the licensed HPV-16/18 AS04-adjuvanted vaccine (control) in healthy 18-25 year-old women.

METHODS

In one trial (NCT00231413), subjects received control or one of 6 tetravalent HPV-16/18/31/45 AS04 vaccine formulations at months (M) 0,1,6. In a second trial (NCT00478621), subjects received control or one of 5 tetravalent HPV-16/18/33/58 vaccines formulated with different adjuvant systems (AS04, AS01 or AS02), administered on different schedules (M0,1,6 or M0,3 or M0,6).

RESULTS

One month after the third injection (Month 7), there was a consistent trend for lower anti-HPV-16 and -18 geometric mean antibody titers (GMTs) for tetravalent AS04-adjuvanted vaccines compared with control. GMTs were statistically significantly lower for an HPV-16/18/31/45 AS04 vaccine containing 20/20/10/10 μg VLPs for both anti-HPV-16 and anti-HPV-18 antibodies, and for an HPV-16/18/33/58 AS04 vaccine containing 20/20/20/20 μg VLPs for anti-HPV-16 antibodies. There was also a trend for lower HPV-16 and -18-specific memory B-cell responses for tetravalent AS04 vaccines versus control. No such trends were observed for CD4(+) T-cell responses. Immune interference could not always be overcome by increasing the dose of HPV-16/18 L1 VLPs or by using a different adjuvant system. All formulations had acceptable reactogenicity and safety profiles. Reactogenicity in the 7-day post-vaccination period tended to increase with the introduction of additional VLPs, especially for formulations containing AS01.

CONCLUSIONS

HPV-16 and -18 antibody responses were lower when additional HPV L1 VLPs were added to the HPV-16/18 AS04-adjuvanted vaccine. Immune interference is a complex phenomenon that cannot always be overcome by changing the antigen dose or adjuvant system.

Effectiveness of quadrivalent human papillomavirus vaccine for the prevention of cervical abnormalities: case-control study nested within a population based screening programme in Australia

OBJECTIVE

To measure the effectiveness of the quadrivalent human papillomavirus (HPV) vaccine against cervical abnormalities four years after implementation of a nationally funded vaccination programme in Queensland, Australia.

DESIGN

Case-control analysis of linked administrative health datasets.

SETTING

Queensland, Australia.

PARTICIPANTS

Women eligible for free vaccination (aged 12-26 years in 2007) and attending for their first cervical smear test between April 2007 and March 2011. High grade cases were women with histologically confirmed high grade cervical abnormalities (n = 1062) and "other cases" were women with any other abnormality at cytology or histology (n = 10,887). Controls were women with normal cytology (n = 96,404).

MAIN OUTCOME MEASURES

Exposure odds ratio (ratio of odds of antecedent vaccination (one, two, or three vaccine doses compared with no doses) among cases compared with controls), vaccine effectiveness ((1-adjusted odds ratio) × 100), and number needed to vaccinate to prevent one cervical abnormality at first screening round. We stratified by four age groups adjusted for follow-up time, year of birth, and measures of socioeconomic status and remoteness. The primary analysis concerned women whose first ever smear test defined their status as a case or a control.

RESULTS

The adjusted odds ratio for exposure to three doses of HPV vaccine compared with no vaccine was 0.54 (95% confidence interval 0.43 to 0.67) for high grade cases and 0.66 (0.62 to 0.70) for other cases compared with controls with normal cytology, equating to vaccine effectiveness of 46% and 34%, respectively. The adjusted numbers needed to vaccinate were 125 (95% confidence interval 97 to 174) and 22 (19 to 25), respectively. The adjusted exposure odds ratios for two vaccine doses were 0.79 (95% confidence interval 0.64 to 0.98) for high grade cases and 0.79 (0.74 to 0.85) for other cases, equating to vaccine effectiveness of 21%.

CONCLUSION

The quadrivalent HPV vaccine conferred statistically significant protection against cervical abnormalities in young women who had not started screening before the implementation of the vaccination programme in Queensland, Australia.

Systematic review and meta-analysis of L1-VLP-based human papillomavirus vaccine efficacy against anogenital pre-cancer in women with evidence of prior HPV exposure

BACKGROUND

It is unclear whether L1-VLP-based human papillomavirus (HPV) vaccines are efficacious in reducing the likelihood of anogenital pre-cancer in women with evidence of prior vaccine-type HPV exposure. This study aims to determine whether the combined results of the vaccine trials published to date provide evidence of efficacy compared with control (hepatitis A vaccine/placebo).

METHODS

A systematic review and meta-analysis was conducted. Randomized-controlled trials (RCTs) were identified from MEDLINE, Embase, Web of Science, PubMed, Cochrane Central Register of Controlled Trials and references of identified studies. The bivalent vaccine containing HPV-16 and 18 VLPs from GlaxoSmithKline Biologicals (Rixenstart, Belgium), the quadrivalent vaccine containing HPV-6, 11, 16, and 18 VLPs from Merck & Co., Inc., (Whitehouse Station, NJ USA), and the HPV-16 monovalent vaccine from Merck Research Laboratories (West Point, PA USA) were evaluated.

FINDINGS

Three RCT reports and two post-trial cohort studies were eligible, comprising data from 13,482 women who were included in the vaccine studies but had evidence of HPV infection at study entry. Data on efficacy was synthesized using the Mantel-Haenszel weighted fixed-effect approach, or where there was heterogeneity between studies, the DerSimonian and Laird weighted random-effect approach. The mean odds ratio (OR) and 95% confidence interval (CI) for the association between Cervarix, Gardasil and HPV-16 monovalent vaccine and HPV-associated cervical intraepithelial neoplasia grade 3 or worse was 0·90 (95% CI: 0·56, 1·44). For the association between Gardasil and HPV-associated vulval/vaginal intraepithelial neoplasia grades 2-3, the overall OR and 95% CI was 2.25 (95% CI: 0·78, 6.50). Sample size and follow-up were limited.

CONCLUSIONS

There was no evidence that HPV vaccines are effective in preventing vaccine-type HPV associated pre-cancer in women with evidence of prior HPV exposure. Small effects of vaccination however cannot be excluded and a longer-term benefit in preventing re-infection remains possible.

Comparison of the immunogenicity of Cervarix® and Gardasil® human papillomavirus vaccines for oncogenic non-vaccine serotypes HPV-31, HPV-33, and HPV-45 in HIV-infected adults

Individuals infected with human immunodeficiency virus (HIV) have excess risk of developing human papillomavirus (HPV)-related disease. A substantial fraction of HPV-associated cancers is caused by HPV serotypes not included in the currently available vaccines. Among healthy women, both Cervarix(®) (HPV-16/18, GlaxoSmithKline Biologicals, GSK) and Gardasil(®) (HPV-6/11/16/18, Merck) have demonstrated partial cross-protection against certain oncogenic non-vaccine HPV-types. Currently, there are no available data on vaccine-induced cross-protection in men and little is known about cross-reactive immunity after HPV-vaccination of HIV-infected individuals. In an investigator-initiated trial, we randomized 91 HIV-positive men and women to receive vaccination with Cervarix(®) or Gardasil(®). The HPV-DNA status of the participants was determined with pcr before and after immunization. Cross-reactive antibody responses against HPV-31, HPV-33, and HPV-45 were evaluated for up to 12 months using a pseudovirion-based neutralization assay (PBNA). Geometric mean antibody titers (GMTs) were compared among vaccine groups and genders at 7 and 12 months.: Both vaccines induced anti-HPV-31, -33, and -45 neutralizing antibodies in participants who were seronegative and HPV-DNA negative for those types at study entry. Geometric mean antibody titers were comparable between vaccine groups. Interestingly, anti-HPV-31 and -33 antibody titers were higher among women compared with men at 7 and 12 months.: In conclusion, both licensed HPV-vaccines induced cross-neutralizing antibodies against frequent oncogenic non-vaccine serotypes HPV-31, HPV-33, and HPV-45 in HIV-infected adults, and women had greater serological responses against HPV-31 and -33 compared with men.

Upscaling human papillomavirus vaccination in high-income countries: impact assessment based on transmission model

BACKGROUND

The decrease in human papillomavirus (HPV) vaccine prices may allow upscale already started vaccination programmes but the advantages of different options are unclear.

METHODS

Using a mathematical model of HPV16 and 18 transmission and data on vaccination coverage from Italy, we compared 3 options to upscale an already started programme targeting 11-year old girls (coverage 65%): a) coverage improvement (from 65% to 90%); b) addition of 11-year-old boys (coverage 65%); or c) 1-year catch-up of older girls (coverage 50%).

RESULTS

The reduction of cervical HPV16/18 infection as compared to no vaccination (i.e. effectiveness against HPV16/18) increased from 76% to 98% with coverage improvement in girls and to 90% with the addition of boys. With higher coverage in girls, HPV16/18 infection cumulative probability by age 35 decreased from 25% to 8% with a 38% increase in vaccine number. The addition of boys decreased the cumulative probability to 18% with a 100% increase in the number of vaccinees. For any coverage in girls, the number of vaccinees to prevent 1 woman from being infected by HPV16/18 by age 35 was 1.5, whereas it was 2.7 for the addition of boys. Catch-up of older girls only moved forward the vaccination effectiveness by 2-5 years.

CONCLUSIONS

Increasing vaccination coverage among girls is the most effective option for decreasing HPV16/18. If not achievable, vaccinating boys is justifiable if vaccine cost has at least halved, because this option would almost double the number of vaccinees.

Type-specific human papillomavirus biological features: validated model-based estimates

Infection with high-risk (hr) human papillomavirus (HPV) is considered the necessary cause of cervical cancer. Vaccination against HPV16 and 18 types, which are responsible of about 75% of cervical cancer worldwide, is expected to have a major global impact on cervical cancer occurrence. Valid estimates of the parameters that regulate the natural history of hrHPV infections are crucial to draw reliable projections of the impact of vaccination. We devised a mathematical model to estimate the probability of infection transmission, the rate of clearance, and the patterns of immune response following the clearance of infection of 13 hrHPV types. To test the validity of our estimates, we fitted the same transmission model to two large independent datasets from Italy and Sweden and assessed finding consistency. The two populations, both unvaccinated, differed substantially by sexual behaviour, age distribution, and study setting (screening for cervical cancer or Chlamydia trachomatis infection). Estimated transmission probability of hrHPV types (80% for HPV16, 73%-82% for HPV18, and above 50% for most other types); clearance rates decreasing as a function of time since infection; and partial protection against re-infection with the same hrHPV type (approximately 20% for HPV16 and 50% for the other types) were similar in the two countries. The model could accurately predict the HPV16 prevalence observed in Italy among women who were not infected three years before. In conclusion, our models inform on biological parameters that cannot at the moment be measured directly from any empirical data but are essential to forecast the impact of HPV vaccination programmes.

Epitope fluctuations in the human papillomavirus are under dynamic allosteric control: a computational evaluation of a new vaccine design strategy

The dynamic properties of the capsid of the human papillomavirus (HPV) type 16 were examined using classical molecular dynamics simulations. By systematically comparing the structural fluctuations of the capsid protein, a strong dynamic allosteric connection between the epitope containing loops and the h4 helix located more than 50 Å away is identified, which was not recognized thus far. Computer simulations show that restricting the structural fluctuations of the h4 helix is key to rigidifying the epitopes, which is thought to be required for eliciting a proper immune response. The allostery identified in the components of the HPV is nonclassical because the mean structure of the epitope carrying loops remains unchanged, but as a result of allosteric effect the structural fluctuations are altered significantly, which in turn changes the biochemical reactivity profile of the epitopes. Exploiting this novel insight, a new vaccine design strategy is proposed wherein a relatively small virus capsid fragment is deposited on a silica nanoparticle in such a way that the fluctuations of the h4 helix are suppressed. The structural and dynamic properties of the epitope carrying loops on this hybrid nanoparticle match the characteristics of epitopes found on the full virus-like particle precisely, suggesting that these nanoparticles may serve as potent, cost-effective, and safe alternatives to traditionally developed vaccines. The structural and dynamic properties of the hybrid nanoparticle are examined in detail to establish the general concepts of the proposed new design.