Sustained efficacy up to 4.5 years of a bivalent L1 virus-like particle vaccine against human papillomavirus types 16 and 18: follow-up from a randomised control trial

How will HPV vaccines affect cervical cancer?

Cancer of the uterine cervix is the second largest cause of cancer deaths in women, and its toll is greatest in populations that lack screening programmes to detect precursor lesions. Persistent infection with 'high risk' genotypes of human papillomavirus (HPV) is necessary, although not sufficient, to cause cervical carcinoma. Therefore, HPV vaccination provides an opportunity to profoundly affect cervical cancer incidence worldwide. A recently licensed HPV subunit vaccine protects women from a high proportion of precursor lesions of cervical carcinoma and most genital warts. Here we examine the ramifications and remaining questions that surround preventive HPV vaccines.

Neutralization of HPV16, 18, 31, and 58 pseudovirions with antisera induced by immunizing rabbits with synthetic peptides representing segments of the HPV16 minor capsid protein L2 surface region

Neutralizing antibody against human papillomavirus (HPV) minor capsid protein L2 can cross-neutralize different HPV genotypes in vitro. To identify the segments containing the cross-neutralization epitopes of HPV16 L2, we characterized antisera obtained by immunizing two rabbits with each of the ten synthetic peptides of 14 to 20 amino acids (aa) long, which represents a part of the HPV16 L2 sequence from aa 14 to 144. The antisera against the peptides within the region from aa 18 to 144 efficiently bound to HPV16 L1/L2-capsids and neutralized HPV16 pseudovirions, indicating that the region is displayed on the surface of the capsids and contains several neutralization epitopes. Antiserum against the peptide from aa 18 to 38 (anti-P18/38) cross-neutralized HPV18. Anti-P56/75 cross-neutralized HPV18, 31, and 58. Anti-P61/75 and anti-P64/81 cross-neutralized HPV18 and 58. Anti-P96/115 and the antiserum induced by a mutant P96/115 (S and T at aa 101 and 112 were replaced with L and S, respectively) cross-neutralized HPV31 and 58. The mixture of equal volumes of three antisera, anti-P18/38, anti-P56/75, and anti-mutant P96/115, neutralized HPV16, 18, 31, and 58 more efficiently than anti-P56/75 alone, suggesting that there is a synergistic effect of antibodies on the cross-neutralization. The cross-neutralization appears to be correlated with conserved aa sequences among HPV types. The data in this study provide a basis for designing vaccine antigens effective against a broader spectrum of the high-risk HPVs.

New paradigm for prevention of cervical cancer

Human papillomavirus (HPV) infection is an event responsible for the development of cervical cancer and its premalignant dysplasia. Prophylactic vaccines based on virus-like particles (VLPs) have been successfully tested in clinical trials. They are safe, close to 100% effective in preventing persistent infection and premalignant disease, and are now being introduced onto the market. Vaccination should be offered primarily to young girls and adolescents 9-15 years of age. Vaccine introduction faces particular problems due to a bias towards sexually transmitted diseases and financing, especially in developing countries. However, it represents the first vaccine that has the potential to eradicate 70% of cervical cancer world wide.

Will widespread human papillomavirus prophylactic vaccination change sexual practices of adolescent and young adult women in America?

Two virus-like particle human papillomavirus (HPV) vaccines have been shown to be nearly 100% effective in preventing type-specific persistent HPV infections and associated type-specific high-grade cervical intraepithelial neoplasia (CIN). Recently, it has been hypothesized that the administration of this vaccine to young girls in the United States might increase sexual promiscuity among adolescent women and/or young adults. Thus, it has been suggested that focused vaccine strategies either based on the risk of CIN or gender might be more rational or cost-effective. However, such strategies are unlikely to completely eradicate the burden of this disease and decrease the cost of cervical cancer screening. The suggestion that widespread vaccination will alter sexual practices is refuted and the rationale for the vaccination of all girls and boys is outlined.

Cellular immune responses to HPV-18, -31, and -53 in healthy volunteers immunized with recombinant HPV-16 L1 virus-like particles

Human papillomavirus-like particles (HPV VLP) are candidate vaccines that have shown to be efficacious in reducing infection and inducing robust antiviral immunity. Neutralizing antibodies generated by vaccination are largely type-specific, but little is known about the type-specificity of cellular immune responses to VLP vaccination. To determine whether vaccination with HPV-16 L1VLP induces cellular immunity to heterologous HPV types (HPV-18, HPV-31, and HPV-53), we examined proliferative and cytokine responses in vaccine (n=11) and placebo (n=5) recipients. Increased proliferative and cytokine responses to heterologous types were observed postvaccination in some individuals. The proportion of women responding to heterologous types postvaccination (36%-55%) was lower than that observed in response to HPV-16 (73%). Response to HPV-16 VLP predicted response to other types. The strongest correlations in response were observed between HPV-16 and HPV-31, consistent with their phylogenetic relatedness. In summary, PBMC from HPV-16 VLP vaccine recipients can respond to L1VLP from heterologous HPV types, suggesting the presence of conserved T cell epitopes.

Annual productivity costs due to cervical cancer mortality in the United States

BACKGROUND

Several studies have estimated annual US health care costs associated with cervical cancer; however, few data are available on the corresponding annual loss in women's productive earnings resulting from premature mortality owing to cervical cancer. The present study estimates annual productivity costs associated with cervical cancer mortality in the United States.

METHODS

An analytic framework was developed for estimating the lost earnings that would have accrued during 2000 for women dying from cervical cancer during that and earlier years, who would have otherwise been alive and working in 2000. The following data from publicly available sources were gathered and analyzed for US women on an age-specific basis: 1) annual number of cervical cancer deaths during 2000 and preceding years; 2) estimated probability of otherwise being alive during 2000, for women dying from cervical cancer during the period 1935-2000; 3) labor force participation rates in 2000; and 4) mean annual earnings in 2000.

RESULTS

Overall, it was estimated that there were 130,377 women who would have been alive during 2000 had they not died from cervical cancer during that or a previous year. Over 75% of these women died before age 60, with >25% dying prior to age 40, and it was estimated that 37,594 (29%) of these women would have had labor force earnings during 2000. The total productivity loss in 2000 owing to cervical cancer mortality was estimated at $1.3 billion.

CONCLUSIONS

The annual productivity loss for cervical cancer estimated in the present analysis is several times higher than recent estimates of the annual US direct medical costs associated with cervical cancer ($300-$400 million).

Human papillomavirus-related tumors in HIV

PURPOSE OF REVIEW

Human papillomavirus-related anogenital cancers are theoretically preventable. Many HIV-infected women do not undergo routine cervical cytology screening, however, and there are currently no routine anal cytology screening programs. This review focuses on recent developments that may impact on the future incidence of these cancers: the effect of highly active antiretroviral therapy and the imminent approval of vaccines to prevent initial human papillomavirus infection.

RECENT FINDINGS

Highly active antiretroviral therapy has limited benefit to reduce the incidence of cervical intraepithelial neoplasia 3 and no benefit to reduce the incidence of anal intraepithelial neoplasia 3. Consistent with these findings, there has been no reduction in the incidence of cervical and anal cancer since the introduction of highly active antiretroviral therapy. More encouraging is the development of highly effective preventive human papillomavirus vaccines that are projected to reduce the incidence of cervical cancer by up to 70% among vaccinated women.

SUMMARY

HIV-positive men and women remain at risk for human papillomavirus-associated cancers, even in the highly active antiretroviral therapy era. Conversely, the incidence of anogenital cancers may decline in the future among HIV-positive individuals if they received the human papillomavirus vaccine before they acquired HIV infection, and studies should be done to assess the safety and efficacy of the vaccines in individuals already infected with HIV.

Cervical cancer prevention in the era of prophylactic vaccines: A preview for gynecologic oncologists

OBJECTIVE

The recent approval of a vaccine to prevent HPV infection is an important advance in cervical cancer prevention. This article is intended to provide gynecologic oncologists with a comprehensive background in modern cervical cancer prevention strategies.

METHODS

We describe and contrast the quadrivalent and bivalent vaccines. More established cervical cancer prevention strategies are reviewed, with comments on the impact of HPV vaccination. Clinical guidance is provided for use of the approved quadrivalent vaccine. Safety and side effects of both vaccines are reviewed and future questions and challenges are explored.

RESULTS

It is vitally important that both vaccinated and unvaccinated women continue to fully engage in cervical cancer prevention, including cervical cancer screening, follow-up of abnormal screens, and treatment of premalignant lesions. A quadrivalent virus-like particle vaccine has now been approved for use in girls and women ages 9 to 26. A bivalent vaccine may be available soon. Vaccine efficacy in clinical trials has been outstanding, with 100% protection against HPV-type-specific cervical intraepithelial neoplasia (CIN) II and III.

CONCLUSIONS

Comprehensive cervical cancer protection now includes prophylactic vaccination for girls and young women in addition to screening and treatment of premalignant changes. Gynecologic oncologists will continue to play an important role in promoting optimal prevention practices.

Therapeutic efficacy of vesicular stomatitis virus-based E6 vaccination in rabbits

Millions of people worldwide are currently infected with human papillomaviruses (HPVs). A therapeutic HPV vaccine would have widespread applicability because HPV-associated lesions are difficult to treat and may progress to carcinoma. We developed three attenuated VSV recombinants expressing the cottontail rabbit papillomavirus (CRPV) early protein E6 for use as vaccines. In cultured cells, two vectors expressed different levels of the E6 protein, and one expressed a ubiquitin-E6 fusion protein. All three were tested for therapeutic efficacy in the cottontail rabbit papillomavirus (CRPV)-rabbit model. Mock vaccination had no effect on papilloma growth. In contrast, inoculation with any of the VSV-E6 vaccines reduced the rate of papilloma growth to as little as 24% the rate in the controls. In five experiments, these effects were achieved after a single immunization. Furthermore, complete papilloma regression occurred in some rabbits observed for 4 months. A VSV-based papillomavirus E6 vaccine could have significant advantages over other therapeutic HPV vaccine candidates described to date.

Drug discovery in the ubiquitin-proteasome system

Regulated protein turnover via the ubiquitin-proteasome system (UPS) underlies a wide variety of signalling pathways, from cell-cycle control and transcription to development. Recent evidence that pharmacological inhibition of the proteasome can be efficacious in the treatment of human cancers has set the stage for attempts to selectively inhibit the activities of disease-specific components of the UPS. Here, we review recent advances linking UPS components with specific human diseases, most prominently cancer and neurodegenerative disorders, and emphasize potential sites of therapeutic intervention along the regulated protein-degradation pathway.

God's Gift to Women: The Human Papillomavirus Vaccine

An Australian newspaper recently bestowed Ian Frazer the title of "God's gift to women" for his research team's part in developing a vaccine to help control cervical cancer. Here Frazer discusses this work and the science behind the vaccine.

Chapter 12: Prophylactic HPV vaccines: Underlying mechanisms

Human papillomavirus virus-like particles (HPV VLP) can be generated by the synthesis and self-assembly in vitro of the major virus capsid protein L1. HPV L1 VLPs are morphologically and antigenically almost identical to native virions, and this technology has been exploited to produce HPV L1 VLP subunit vaccines. The vaccines elicit high titres of anti-L1 VLP antibodies that persist at levels 10 times that of natural infections for at least 48 months. At present the assumption is that the protection achieved by these vaccines against incident HPV infection and HPV-associated ano-genital pathology is mediated via serum neutralising Immunoglobulin G (IgG). However, since there have been very few vaccine failures thus far, immune correlates of protection have not been established. The available evidence is that the immunodominant neutralising antibodies generated by L1 VLPs are type-specific and are not cross-neutralising, although highly homologous HPV pairs share minor cross-neutralisation epitopes. Important issues remaining to be addressed include the duration of protection and genotype replacement.

Chapter 3: HPV type-distribution in women with and without cervical neoplastic diseases

Geographical widespread data on human papillomavirus (HPV) type-distribution are essential for estimating the impact of HPV-16/18 vaccines on cervical cancer and cervical screening programmes. Epidemiological studies employing a variety of HPV typing protocols have been collated in meta-analyses. HPV-16/18 is estimated to account for 70% of all cervical cancers worldwide, although the estimated HPV-16/18 fraction is slightly higher in more developed (72-77%) than in less developed (65-72%) regions. About 41-67% of high-grade squamous intraepithelial lesion (HSIL), 16-32% of low-grade squamous intraepithelial lesion (LSIL) and 6-27% of atypical squamous cells of undetermined significance (ASCUS) are also estimated to be HPV-16/18-positive, thus highlighting the increasing relative frequency of HPV-16/18 with increasing lesion severity. After HPV-16/18, the six most common HPV types are the same in all world regions, namely 31, 33, 35, 45, 52 and 58; these account for an additional 20% of cervical cancers worldwide.

Chapter 16: HPV vaccines in immunocompromised women and men

HIV-positive as well as other immunocompromised women and men have increased risk of human papillomavirus (HPV)-associated anogenital and oral cancers. The effectiveness of a HPV vaccine to reduce the incidence of these tumors in immunocompromised individuals may depend on several factors, including the effects of immunocompromise on the response to vaccination, the extent of prior infection with the HPV types included in the vaccine, whether immunocompromised women and men have tumors that contain types of HPV not in the vaccines more often than the general population, and whether or not immunization occurs before immunocompromise is severe. Clinical studies are needed to determine HPV vaccine safety and effectiveness in different populations of immunocompromised women and men.

Chapter 28: Studies to assess the long-term efficacy and effectiveness of HPV vaccination in developed and developing countries

We review studies of the implementation of human papillomavirus (HPV) vaccination programmes in developed and developing countries. The review spans the period from establishment of long-term vaccine efficacy follow-up studies, operational research on issues of vaccine preparedness, and relevant predictive modelling studies during the pre-licensure phase to plans of phase IV effectiveness trials, forms of epidemiological surveillance, and further operational research in the post-licensure phase. Much of the research is already ongoing. Depending on the results of the planned immuno bridging studies among HIV-negative and HIV-positive women, further phase III and/or phase IV trials may be warranted.

Chapter 13: Current findings from prophylactic HPV vaccine trials

Early data from randomized controlled trials consistently show that prophylactic human papillomavirus virus-like particle (HPV VLP) vaccines are effective in preventing infection and lesions caused by the targeted HPV type(s). Two vaccines, a bivalent HPV-16/18 VLP vaccine and a quadrivalent HPV-6/11/16/18 VLP vaccine, are currently undergoing evaluation in phase III trials with anticipation of receiving regulatory approval for use in immunization programs worldwide. Both vaccines have the potential to substantially reduce HPV-related morbidity and mortality. This review focuses on published data from clinical trials of these two vaccines.

Chapter 30: HPV vaccines and screening in the prevention of cervical cancer; conclusions from a 2006 workshop of international experts

The finding that cervical cancer only occurs in women infected with specific, "high-risk" types of the human papillomavirus (HPV) has led to the development of novel, non-cytology-based cervical cancer prevention strategies. We now have sensitive molecular methods for detecting HPV that dramatically improve our ability to detect high-grade cervical cancer precursor lesions. Perhaps more importantly, prophylactic HPV vaccines have been developed that are protective against cervical cancer precursors caused by HPV 16 and 18. In the Spring of 2006, over 100 experts in HPV, cervical cancer screening, and vaccination worked together to define how best to incorporate HPV DNA testing and the HPV vaccines into cervical cancer prevention efforts. In this summary, we summarize the opinions of this expert group on how these advances can be introduced to provide the maximum benefit to women and to reduce the global burden of cervical cancer.

Genital human papillomavirus infection

Over the past few decades, epidemiology and natural history studies have led to improved understanding of human papillomavirus (HPV) infection and to promising prevention strategies. HPV infection is the cause of anogenital warts and cervical cancer, as well as a proportion of other anogenital and head and neck cancers. Data from clinical trials have resulted in recommendations that support the use of an HPV test in the context of cervical cancer screening and management. Prophylactic HPV vaccine trials have demonstrated high efficacy, and an HPV vaccine that prevents cervical cancer precursors, cervical cancer, and anogenital warts caused by HPV types 6, 11, 16, and 18 was licensed for use in girls and women aged 9-26 years by the US Food and Drug Administration (FDA) in June 2006. In this article, we review genital HPV for the clinician, with a primary focus on the prevalence of HPV infection in the United States.

Vaccins prophylactiques antipapillomavirus : enjeux et perspectives

Human Papillomavirus (HPV) infection is established as the necessary cause of cervical precancers and cancers. To date, more than 120 genotypes are known, but only high risk oncogen genotypes could induce a cancer. HPV 16 and 18 are implied in nearly 70% of cervical cancer around the world. Although some persistent HPV infections progress to cervical cancer, host immunity is generally able to clear most HPV infections providing an opportunity for cervical cancer prevention through vaccination. Candidate prophylactic vaccines based on papillomavirus L1 virus-like particles (VLPs) are currently on human clinical trials: one targeting cervical cancer with a bivalent VLP L1 vaccine containing the two genotypes most frequently involved in cervical cancer (type 16 and 18) and the other, protecting against warts as well as cervical cancer, with a quadrivalent HPV VLP L1 vaccine containing genotypes 6, 11, 16 and 18. The first clinical trials revealed the satisfactory tolerance and excellent immunogenicity of these vaccines inducing high serum antibody titers with minimal side effects. After more than three years, both clinical trials on women 15 to 25 years old have shown that vaccines are able to type specifically protect against nearly 90% of infection and all cervical intra-epithelial neoplasia. The vaccinal strategy defined to date targets preadolescents and adolescent young females (11-13 years) before the first sexual course but some questions are still not resolved concerning the prescriber, the actors of the vaccination and the duration of the protection. Nevertheless cervical cancer screening should be carried on for many years, even if a large vaccinal strategy is decided. Such a vaccine would save lives and reduce the need for costly medical procedures and the psychological stress induced by this cancer.

Chapter 27: Research needs following initial licensure of virus-like particle HPV vaccines

Human papillomavirus virus-like particle (HPV VLP) HPV vaccines currently evaluated for licensing are likely to be available soon. Licensure will be based on evidence that the vaccine is well tolerated and provides near complete type-specific protection against HPV infections and their resulting lesions in the first few years after vaccination. Several important questions will remain to be answered after licensure to guide vaccine implementation and to permit the rational evaluation of vaccination in cancer prevention programs. These include the long-term safety and efficacy of vaccination, the optimal ages for vaccination, efficacy against HPV types not included in the vaccine and against existing infections, and efficacy in males. Modulators of vaccine efficacy (e.g., HIV infection) and immune mechanisms of long-term protection also remain to be defined. The real-world effectiveness of vaccination programs will need to be assessed. Issues related to the implementation of a vaccine that targets pre-adolescents and early adolescents and to the acceptability of a cancer vaccine targeted against a sexually transmitted infection will need to be understood before vaccination programs can be successful. It is hoped that continued improvements to the current HPV vaccines will lead to the introduction in future years of second generation vaccines that simplify delivery and/or expand its coverage. Finally, the natural history of HPV types not covered in the candidate vaccines will need to be carefully studied following vaccination. Public health authorities in various countries will play a pivotal role in determining if these questions are answered in a timely manner.

HPV testing in routine cervical screening: cross sectional data from the ARTISTIC trial

To evaluate the effectiveness of human papillomavirus (HPV) testing in primary cervical screening. This was a cross-sectional study from the recruitment phase of a prospective randomised trial. Women were screened for HPV in addition to routine cervical cytology testing. Greater Manchester, attendees at routine NHS Cervical Screening Programme. In all, 24 510 women aged 20–64 screened with liquid-based cytology (LBC) and HPV testing at entry. HPV testing in primary cervical screening. Type-specific HPV prevalence rates are presented in relation to age as well as cytological and histological findings at entry. In all, 24 510 women had adequate cytology and HPV results. Cytology results at entry were: 87% normal, 11% borderline or mild, 1.1% moderate and 0.6% severe dyskaryosis or worse. Prevalence of HPV decreased sharply with age, from 40% at age 20–24 to 12% at 35–39 and 7% or less above age 50. It increased with cytological grade, from 10% of normal cytology and 31% of borderline to 70% mild, 86% moderate, and 96% of severe dyskaryosis or worse. HPV 16 or HPV 18 accounted for 64% of infections in women with severe or worse cytology, and one or both were found in 61% of women with severe dyskaryosis but in only 2.2% of those with normal cytology. The majority of young women in Greater Manchester have been infected with a high-risk HPV by the age of 30. HPV testing is practicable as a primary routine screening test, but in women aged under 30 years, this would lead to a substantial increase in retesting and referral rates. HPV 16 and HPV 18 are more predictive of underlying disease, but other HPV types account for 30% of high-grade disease.

Chapter 20: Issues in planning cervical cancer screening in the era of HPV vaccination

Human Papillomavirus (HPV) vaccines will likely have an impact as a preventive strategy for cervical cancer. Screening for precancerous lesions cannot be discontinued because vaccination will not protect against HPV types not included in the first generation of vaccines. Moreover, protection for the target types, 16 and 18, which are responsible for most cases of cervical precancerous lesions and cancer, and 6 and 11, which are responsible for a substantial proportion of low-grade lesions, cannot be expected to be absolute, and the likely implementation of HPV vaccination in young women will not impact older groups initially. Cervical cancer control programs will need to be re-evaluated because the addition of HPV vaccination will make the existing approach of high-frequency screening by cytology too costly and inefficient for most public health budgets. Simply making cytology screening less frequent may not be a viable strategy in light of potential problems that may plague cytology performance in conditions of low lesion prevalence. HPV testing has the performance characteristics that would make it an ideal primary screening test in such conditions. Cytology should be reserved for triage of HPV-positive cases because it is more likely to perform with sufficient accuracy in high-prevalence conditions. Another advantage of using HPV testing as a primary screening tool is the opportunity to create infection registries that can link test results from the same women over time, thus allowing an efficient and low-cost strategy to monitor long-term protection among vaccinated women.

Flat penile lesions: The infectious “invisible” link in the transmission of human papillomavirus

Although it has been widely accepted that high-risk human papillomavirus (hrHPV) is sexually transmitted, limited insight is available about the clinical manifestations of hrHPV infection in men and their contribution in the viral spread. Here, we reviewed the literature on the relationship between hrHPV and the presence of penile lesions. Flat penile lesions have similar predilection sites as HPV, often contain hrHPV as identified by DNA in situ hybridization in biopsy specimens, show a high association with hrHPV as identified by PCR in penile scrapes of lesional sites and are associated with high viral copy numbers. Absence of flat lesions is generally associated with very low HPV copy numbers or absence of HPV. Therefore, we argue that these lesions form the reservoir of hrHPV in men and contribute to the viral spread. Their bare visibility with the naked eye and their high degree of spontaneous healing explain why flat penile lesions have slipped the attention of the clinician. Combining an HPV DNA test with a visual inspection after acetic acid application offers a more reliable interpretation of a positive HPV test in men, as it helps to distinguish positivity that is very likely to reflect a productive HPV infection from potentially HPV infections with very low copy numbers or HPV contamination by the sex partner. Future trials of HPV vaccines in men should take into account not only the presence of penile HPV but also the presence of flat penile lesions as an outcome measure for the efficacy of a vaccine.

Prevalence of alpha-papillomavirus genotypes in cervical squamous intraepithelial lesions and invasive cervical carcinoma in the Italian population

The aim of the present investigation was to define the spectrum of mucosotropic human papillomaviruses among 414 Italian women with normal cervices (n = 183), low- and high-grade cervical squamous intraepithelial lesions (n = 101 and 65, respectively), and invasive squamous cervical carcinomas (n = 65). Human papillomaviruses were detected by broad spectrum consensus-primer-pairs MY09/MY11 and GP5+/GP6+-based polymerase chain reaction using three amplification methods and were characterized by nucleotide sequence analysis. The prevalence rates of HPV infections was 19.7%, 63.4%, 80%, and 81.5% in patients with normal cervices, low-grade, and high-grade squamous intraepithelial lesions, and cervical carcinomas, respectively. Among the 205 HPV-positive patients, a total of 31 mucosal HPV genotypes were identified of which 16 types, epidemiological classified as high-risk viruses (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 66, 68, 73, and 82), have been found in 16.9%, 50.1%, 69.2%, and 78.5% of normal cervix, low-, and high-grade cervical squamous intraepithelial lesions, and cervical carcinoma groups, respectively. As expected, the HPV16 was the most represented viral type in all groups examined with frequency rates ranging from 8.7% in normal subjects to 58.5% in invasive carcinoma patients. Ten epidemiologically defined low-risk HPV types (HPV6, 11, 42, 54, 61, 70, 71, 72, 81, 83) were detected in 2.7%, 7.9%, and 6.1% of normal cervix, low-, and high-grade cervical squamous intraepithelial lesions, respectively, and in none of invasive carcinomas. Furthermore, five unknown risk viruses were detected in 3% of low-grade cervical squamous intraepithelial lesions (HPV30, 32, 67), in 3.1% of high-grade cervical squamous intraepithelial lesions (HPV62, 90), and in 1.5% of cervical carcinomas (HPV62). Larger epidemiological screening studies, with PCR amplification and followed by either hybridization-based procedures against sequence targets of all known HPV types or sequence analysis studies, are needed in order to assess the epidemiological risk of less represented HPV types, to identify unknown viruses, and to monitor the future eventual spread of unusual viral types related to vaccination programs and/or population mobility.