Human papilloma virus vaccination: impact and recommendations across the world

Natural Language Processing-Powered Real-Time Monitoring Solution for Vaccine Sentiments and Hesitancy on Social Media: System Development and Validation

BACKGROUND

Vaccines serve as a crucial public health tool, although vaccine hesitancy continues to pose a significant threat to full vaccine uptake and, consequently, community health. Understanding and tracking vaccine hesitancy is essential for effective public health interventions; however, traditional survey methods present various limitations.

OBJECTIVE

This study aimed to create a real-time, natural language processing (NLP)-based tool to assess vaccine sentiment and hesitancy across 3 prominent social media platforms.

METHODS

We mined and curated discussions in English from Twitter (subsequently rebranded as X), Reddit, and YouTube social media platforms posted between January 1, 2011, and October 31, 2021, concerning human papillomavirus; measles, mumps, and rubella; and unspecified vaccines. We tested multiple NLP algorithms to classify vaccine sentiment into positive, neutral, or negative and to classify vaccine hesitancy using the World Health Organization's (WHO) 3Cs (confidence, complacency, and convenience) hesitancy model, conceptualizing an online dashboard to illustrate and contextualize trends.

RESULTS

We compiled over 86 million discussions. Our top-performing NLP models displayed accuracies ranging from 0.51 to 0.78 for sentiment classification and from 0.69 to 0.91 for hesitancy classification. Explorative analysis on our platform highlighted variations in online activity about vaccine sentiment and hesitancy, suggesting unique patterns for different vaccines.

CONCLUSIONS

Our innovative system performs real-time analysis of sentiment and hesitancy on 3 vaccine topics across major social networks, providing crucial trend insights to assist campaigns aimed at enhancing vaccine uptake and public health.

Distribution of high- and low-risk human papillomavirus genotypes and their prophylactic vaccination coverage among West African women: systematic review

INTRODUCTION

The second most deadly gynecological cancer worldwide, cervical cancer is steadily on the rise in sub-Saharan Africa, while vaccination programs are struggling to get off the ground. This systematic review's aim was to assess the prevalence and distribution of high- and low-risk HPV genotypes in West African women.

METHODS

Original studies were retrieved from PubMed/Medline, Embase, Scopus, Google Scholar, and Science Direct. In these studies, Human papillomavirus (HPV) DNA was assessed in cervical samples by polymerase chain reaction (PCR), Hybrid capture, and sequencing. The quality of the articles was assessed and the results were extracted and reviewed.

RESULTS

Thirty-nine studies from 10 West African countries were included for the systematic review including 30 for the pooled analysis. From an overall of 17358 participants, 5126 of whom were infected with at least one HPV genotype, the systematic review showed a prevalence varying from 8.9% to 81.8% in the general population. In contrast, the pooled prevalence of infection was 28.6% (n = 3890; 95% CI 27.85-29.38), and HPV-52 (13.3%), HPV-56 (9.3%), and HPV-35 (8.2) were the most frequent. Quadrivalent and nonavalent vaccines covered 18.2% and 55.8% of identified genotypes respectively.

CONCLUSION

Faced with this growing public health challenge in West Africa, it would be necessary for all its countries to have reliable data on HPV infection and to introduce the nonavalent vaccine. A study of the genotypic distribution of HPV in high-grade precancerous lesions and cervical cancer would be very useful in West Africa.

Determinants of Low-Income Women's Participation in Self-Collected Samples for Cervical Cancer Detection: Application of the Theory of Planned Behavior

BACKGROUND

Low-income women (LIW) are underrepresented in physician-provided cervical cancer screening. Providing women with an option for Human Papillomavirus (HPV) self-sampling would increase cervical cancer screening. However, little is known about LIW's attitude towards self-sampling for cervical cancer. We determined the associations between the Theory of Planned Behavior (TPB) constructs and LIW intention for participation in the HPV self-sampling.

METHODS

A 44-item survey was administered among women receiving food from a food pantry in central Texas. Independent variables included TPB constructs (i.e., attitudes, subjective norms, and perceived control). The outcome variables were intentions and preference for self-sampling. Both variables were measured on a 5-point scale. Hierarchical linear regression models were used to analyze the data.

RESULTS

A sample of 241 participants (age 50.13 ± 9.60 years) comprising non-Hispanic White (40%), Black/African American (27%), and Hispanic (30%) participated in the study. The participants were current with a pap test (54.8%) and preferred self-sampling (42%). The participant's attitudes and subjective norms were significantly associated with their intention for self-sampling, accounting for 38.7% of the variance (p < .001). Women who were overdue for pap testing versus current with pap testing had increased odds of preferring self-sampling (OR = 1.72, 95% CI: 1.27, 6.04).

CONCLUSIONS

The key predictors for LIW's intention for self-sampling included attitudes and subjective norms. Future research should use the TPB as a framework to examine whether intention predicts self-sampling behavior among LIW.

The Consensus Project: Participation in cervical cancer screening by the first cohorts of girls offered HPV vaccination at age 15-16 years in Italy

OBJECTIVE

To evaluate the association between human papillomavirus vaccination status and participation in cervical cancer screening (at age 25) by the first cohorts of girls who were offered vaccination at the age of 15 to 16 years in Italy.

METHODS

Women born in 1993, 1994 and 1995 were invited to participate in cervical cancer screening between 2018 and 2020. We report participation in screening by vaccination status in three large areas, Florence province, Piedmont region and Savona province, where the Consensus Project was carried out. The relative risk of participation among vaccinated (≥2 doses) and unvaccinated women was estimated. Odds ratios (OR) of participation by vaccination status were estimated by logistic regression, adjusted by birthplace and birth cohort.

RESULTS

Overall, 34,993 women were invited for screening: 13,006 (37.2%) participated and 10,062 of these agreed to participate in the Consensus intervention study. Among the invited women and screening participants, vaccinated women were 51.0% and 60.6%, respectively. Comparing vaccinated and unvaccinated women, the adjusted OR of screening participation was 1.80 (95% confidence interval (CI): 1.72-1.89), 2.17 (95% CI: 1.94-2.42), 1.59 (95% CI: 1.50-1.68) and 1.15 (95% CI: 0.86-1.54) for overall, Florence, Piedmont and Savona, respectively. About 33% of the invited women were unvaccinated and did not participate in screening: 25.8%, 59.5% and 64.2% of women born in Italy, in high migration pressure countries and in advanced development countries, respectively.

CONCLUSIONS

Screening participation was higher among vaccinated than unvaccinated women. Active policies are needed to reduce inequalities, targeting the unscreened and unvaccinated population, particularly non-native women, to accelerate cervical cancer elimination in Italy.

Parental knowledge, views, and perceptions of human papilloma virus infection and vaccination-cross-sectional descriptive study

Human papillomavirus (HPV) is a highly contagious virus that is linked to cervical cancer and is a major public health issue. Saudi Arabia national efforts aimed to have females aged 9-25 years to receive the available vaccine.

Objectives

This study aims to explore parental knowledge, views, and perceptions around HPV in Saudi Arabia.

Methods

A cross-sectional online questionnaire was used through direct interview to collect information from a group of parents attending King Abdul-Aziz University Hospital in Jeddah, Saudi Arabia. The questionnaire comprised items including demographics, knowledge, views, and perceptions of HPV infection and vaccination.

Results

Of the 500 parents who participated in this study, only 54 (11%) had heard about HPV being associated with cervical cancer. The majority of the participants reported being from the middle social class (n = 472, 94.4%). The vast majority (n = 483, 96.8%) had never heard of the HPV vaccine and (n = 470, 94%) were unwilling to vaccinate their daughters. The primary reported reason behind refusing the vaccine was the lack of information on the importance of HPV vaccination (n = 426, 85.2%). The majority (n = 419, 83.8%) believed that there was insufficient information regarding vaccine safety and efficacy. Participants suggested ways to increase vaccination acceptance like social media awareness (n = 369, 73.8%), educational seminars in schools (n = 254, 50.8%), and a governmental platform (n = 218, 43.6%) providing information on HPV infection and promoting vaccination.

Conclusion

Parents in the present study demonstrated a substantial lack of knowledge about HPV infection and vaccination, which may necessitate the establishment of national awareness campaigns.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Chapter XX Antiviral Treatment and Cancer Control

Hepatitis B virus (HBV), hepatitis C virus (HCV), human papilloma virus (HPV), Epstein-Barr virus (EBV), human T-cell lymphotropic virus type 1 (HTLV-1), Kaposi's sarcoma-associated herpesvirus (KSHV), and Merkel cell polyomavirus (MCV) contribute to about 10-15% global burden of human cancers. Conventional chemotherapy or molecular target therapies have been used to treat virus-associated cancers. However, a more proactive approach would be the use of antiviral treatment to suppress or eliminate viral infections to prevent the occurrence of cancer in the first place. Antiviral treatments against chronic HBV and HCV infection have achieved this goal, with significant reduction in the incidence of hepatocellular carcinoma in treated patients. Antiviral treatments for EBV, KSHV, and HTLV-1 had limited success in treating refractory EBV-associated lymphoma and post-transplant lymphoproliferative disorder, KSHV-associated Kaposi's sarcoma in AIDS patients, and HTLV-1-associated acute, chronic, and smoldering subtypes of adult T-cell lymphoma, respectively. Therapeutic HPV vaccine and RNA interference-based therapies for treating HPV-associated infection or cervical cancers also showed some encouraging results. Taken together, antiviral therapies have yielded promising results in cancer prevention and treatment. More large-scale studies in a real-world setting are necessary to confirm the efficacy of antiviral therapy. Further investigation for more effective and convenient antiviral regimens warrants more attention.

Personalized Human Papillomavirus Vaccination for Persistence of Immunity for Cervical Cancer Prevention: A Critical Review With Experts' Opinions

The development of cervical cancer has been shown to involve both viral and host factors. The host factors are those that determine the specific response to human papillomavirus (HPV) infection by the patient's immune system. The immune responses to vaccines have been shown to be influenced by polymorphisms in genes involved in innate and adaptive immunity. The specific genetic variants that may influence the immune responses to HPV vaccine which may contribute to persistence of immunity (POI) have not been widely studied yet. In order to address the question as to “is it right to vaccinate all children, and all with equal dose?” we have critically examined the knowledge of common immunogenetic and immunogenomic variations that may influence the HPV vaccine POI across various populations. We have also identified a number of specific research questions that need to be addressed in future research into host molecular genetic variations and HPV vaccine POI in order to afford life-long protection against the development of cervical cancer. This work informs future insights for improved HPV vaccine designs based on common host molecular genetic variations.

Immunogenicity and safety of human papillomavirus vaccine coadministered with other vaccines in individuals aged 9-25 years: A systematic review and meta-analysis

INTRODUCTION

Adolescents and young adults are at a high risk of developing human papillomavirus (HPV) infections, which can be prevented with the use of vaccines. Moreover, a combined immunization strategy for administration of HPV vaccines with other routine vaccines may lead to better compliance. We aim to comprehensively evaluate immunogenicity and safety in the case of concomitantly administered HPV vaccine in individuals aged 9-25 years.

METHODS

Relevant studies, published up to December 27, 2018, were identified through searches of Medline/PubMed, EMBASE, Web of Knowledge. The pooled relative risk (RR) of immunogenicity and safety information pertaining to the concomitant administration of HPV vaccines with other routine vaccines in healthy participants aged 9-25 years were evaluated.

RESULTS

A total of 13 papers (11,657 participants) were included in this meta-analysis. The analyses showed that, between the concomitant and nonconcomitant administration groups, the seroconversion rate for the specific antibodies against all HPV types (type 16-, 18-, 6-, 11-, 31-, 33-, 45-, 52-, and 58) were the same (the pooled RR = 1.00, 95% confidence interval (CI) of 1.00-1.00); for the bivalent HPV (2vHPV) vaccine, the risks of local adverse events showed no significant difference (the pooled RR = 1.00, 95%CI: 0.97-1.04), and the risks of systemic adverse events were almost similar (the pooled RR = 1.10, 95% CI: 1.03-1.18); for the non-bivalent HPV (4vHPV and 9vHPV) vaccines, the risks of local adverse events were slightly higher in the concomitant administration groups (the pooled RR = 1.31, 95%CI: 1.17-1.47), and the risks of systemic adverse events were higher in the concomitant administration groups (the pooled RR = 2.09, 95% CI: 1.69-2.59).

CONCLUSIONS

We believe that the concomitant administration of other vaccines along with HPV vaccine is acceptable and there is no interference with the immune response to HPV vaccine. Concomitant vaccine administration has the potential to minimize the number of vaccination visits, leading to increased compliance, hence more effective disease prevention.

The First Clinical Use of a Recombinant Lactococcus lactis Expressing Human Papillomavirus Type 16 E7 Oncogene Oral Vaccine: A Phase I Safety and Immunogenicity Trial in Healthy Women Volunteers

A dose-escalation, randomized, double-blind, placebo-controlled phase I clinical trial was performed in healthy Iranian volunteer women to assess the safety, tolerability, and immunogenicity of NZ8123-HPV16-optiE7 vaccine involving recombinant Lactococcus lactis expressing the codon-optimized human papillomavirus (HPV)-16 E7 oncogene. Fifty-five eligible subjects were divided into 6 cohorts based on the dosages (1 × 10⁹, 5 × 10⁹, and 1 × 10¹⁰ CFU/mL) of either vaccine or placebo, which were administrated orally a total of 4 times at weeks 1, 2, 4, and 8. Then, adverse events, specific serum IgG and vaginal IgA, and E7-specific IFNγ-secreting CD8⁺ CTL responses were evaluated. The vaccination was well tolerated by 40 subjects who completed the immunization schedule, and no serious adverse effects were reported. The IgG and IgA levels peaked at day 60, and the levels for the 5 × 10⁹ CFU/mL and 1 × 10¹⁰ CFU/mL dose groups were higher than those for the 1 × 10⁹ CFU/mL dose group. Time-to-peak stimulation in E7-specific IFNγ-secreting CD8⁺ CTL responses was seen in cervical lymphocytes 1 month after the last vaccination. Again, no significant increase was seen in the peripheral blood mononuclear cells (PBMC) of the same volunteers. CTL responses in cervical lymphocytes and PBMCs at day 90 were markedly higher in the 5 × 10⁹ and 1 × 10¹⁰ CFU/mL groups than in the 1 × 10⁹ CFU/mL group, demonstrating the dose dependency of NZ8123-HPV16-optiE7 vaccine following oral administration. The 6-month follow-up revealed that antibody levels decreased up to day 240; nevertheless, long-term E7-specific IFNγ-secreting CD8⁺ CTL responses were recorded during follow-up. Overall, the safety and immunogenicity profile achieved in this study encourages further phase II trials with the 5 × 10⁹ CFU/mL dose vaccine.

Factors that influence acceptance of human papillomavirus (HPV) vaccination for adolescents: a qualitative evidence synthesis

This is a protocol for a Cochrane Review (Qualitative). The objectives are as follows:

The objectives of the review are to:

Identify, appraise, and synthesise qualitative studies exploring: parents’, caregivers’, or adolescents’ views, experiences, or decision‐making regarding HPV vaccination; or the factors influencing the acceptance of HPV vaccination arising from parents’, caregivers’, and adolescents’ accounts. Identify the factors influencing parents’, caregivers’ and adolescents’ acceptance of HPV vaccination. Explore how the findings of this review can enhance our understanding of the related intervention review (Abdullahi 2015 ).

Phase 1 Safety and Immunogenicity Trial of Recombinant Lactococcus lactis Expressing Human Papillomavirus Type 16 E6 Oncoprotein Vaccine

The present study purposed to investigate the safety, tolerability, and immunogenicity of the therapeutic NZ8123-HPV16-optiE6 vaccine, following oral vaccination. The safety and tolerability were evaluated. Specific serum immunoglobulin G (IgG) and vaginal IgA antibodies were calculated by ELISA, and E6-specific IFN-γ-secreting T cells were counted by enzyme-linked immune absorbent spot (ELISpot) assay in cervical lymphocytes and PBMC samples. The vaccine was well tolerated, and no serious adverse effects were observed in vaccine recipients. Statistical analysis showed that all vaccine groups had significant increases in antibody levels at day 60 after baseline. The time to peak activation in E6-specific IFN-γ-secreting CD8⁺ CTL responses was seen at month 1 after last vaccination. According to the results, the humoral immune and cell-mediated responses for the vaccine groups that received 5 × 10⁹ and 1 × 10¹⁰ CFU/mL of vaccine were similar and were higher than those of the 1 × 10⁹ CFU/mL group, indicating the dose-dependency of the NZ8123-HPV16-optiE6 vaccine following oral administration. Low antibody levels compared with the placebo groups were recorded at month 6 after the last vaccination. Interestingly, long-term E6-specific CTL responses were observed during follow-up. It was concluded that oral immunization with the NZ8123-HPV-16-optiE6 vaccine is safe, induces persistent immunity, and is reasonably well tolerated.

Characteristics of HPV-unvaccinated undergraduate health students in Switzerland, a cross sectional study

Background

Human Papillomavirus (HPV) vaccination, intended for young women aged 11-14 years old, has been introduced in Switzerland in 2007. Ten years after its introduction, only a few studies have explored the reasons associated with uptake and non-uptake of the vaccination. Our objective was to identify the sociodemographic characteristics of a population of vaccinated and unvaccinated undergraduate healthcare female students, to define the reasons of non-uptake of vaccination, and compare our findings with those found in other Swiss cantons.

Methods

Between January and November 2017, women studying in Health Sciences School and Medical School in Geneva, aged 18-31 years old, were recruited in a large trial assessing HPV prevalence. As part of a smaller, observational study nested in this larger trial, women were invited to complete a questionnaire. Self-reported HPV vaccination uptake or non-uptake, as well as knowledge and attitude about HPV vaccination were assessed. T-Test and Chi square test were used to compare characteristics of vaccinated and unvaccinated women.

Results

Overall, 409 women were recruited in the study. The majority of them (69.1%) reported having been vaccinated for HPV, while 30.9% of them had never received any dose of the HPV vaccine. The only factor associated with a higher vaccination rate was the participants' origin, as women from Geneva were more represented in the vaccinated group than women from other Swiss regions or countries. Unvaccinated women were more likely to consider HPV vaccination as less important than the vaccinated ones (50.4% vs 3.5% p < 0.001).

Conclusion

Although no typical profile can be established in this studied population of unvaccinated women, a lack of information was a major reason of non-uptake of vaccination among the study participants. An effort by health authorities and carefully designed messages are essential to increase the population's awareness over cervical cancer and its prevention.

Trial registration

The trial was registered under cliniclatrials.gov with the identifier: NCT03474211.

Advances in Designing and Developing Vaccines, Drugs and Therapeutic Approaches to Counter Human Papilloma Virus

Human papillomavirus (HPV) is a viral infection with skin-to-skin based transmission mode. HPV annually caused over 500,000 cancer cases including cervical, anogenital and oropharyngeal cancer among others. HPV vaccination has become a public-health concern, worldwide, to prevent the cases of HPV infections including precancerous lesions, cervical cancers, and genital warts especially in adolescent female and male population by launching national programs with international alliances. Currently, available prophylactic and therapeutic vaccines are expensive to be used in developing countries for vaccination programs. The recent progress in immunotherapy, biotechnology, recombinant DNA technology and molecular biology along with alternative and complementary medicinal systems have paved novel ways and valuable opportunities to design and develop effective prophylactic and therapeutic vaccines, drugs and treatment approach to counter HPV effectively. Exploration and more researches on such advances could result in the gradual reduction in the incidences of HPV cases across the world. The present review presents a current global scenario and futuristic prospects of the advanced prophylactic and therapeutic approaches against HPV along with recent patents coverage of the progress and advances in drugs, vaccines and therapeutic regimens to effectively combat HPV infections and its cancerous conditions.

Prevention of Cervical Cancer in Sub-Saharan Africa: The Advantages and Challenges of HPV Vaccination

Cervical cancer is a critical public health issue in sub-Saharan Africa (SSA), where it is the second leading cause of cancer among women and the leading cause of female cancer deaths. Incidence and mortality rates are substantially higher than in high-income countries with population-based screening programs, yet implementing screening programs in SSA has so far proven to be challenging due to financial, logistical, and sociocultural factors. Human Papillomavirus (HPV) vaccination is an effective approach for primary prevention of cervical cancer and presents an opportunity to reduce the burden from cervical cancer in SSA. With a number of SSA countries now eligible for Global Alliance for Vaccines and Immunization (GAVI) support for vaccine introduction, it is timely to consider the factors that impede and facilitate implementation of vaccine programs in SSA. This article describes epidemiological features of cervical cancer in SSA and the current status of HPV vaccine implementation in SSA countries. Rwanda’s experience of achieving high vaccination coverage in their national HPV immunization program is used as a case study to explore effective approaches to the design and implementation of HPV vaccination programs in SSA. Key factors in Rwanda’s successful implementation included government ownership and support for the program, school-based delivery, social mobilization, and strategies for reaching out-of-school girls. These findings might usefully be applied to other SSA countries planning for HPV vaccination.

Human papillomavirus load in benign HPV-associated oral lesions from HIV/AIDS individuals

BACKGROUND

Although HPV emerged as a crucial carcinogenic and prognostic biomarker in head and neck cancer, and considering the increase in HPV-associated oral lesions (HPV-OLs) in HIV individuals, molecular information about HPV-OLs is scarce; thus, our aim was to determine viral loads in HPV-OLs from HIV/AIDS individuals.

METHODS

HIV/AIDS subjects with HPV-OL were included in this cross-sectional study. Following informed consent, biopsies were obtained. HPV detection and typing were carried out by PCR and sequencing (MY09/11, GP5+/6+). HPV-13 and HPV-32 loads were determined by a high-resolution melting assay. For statistical analysis, X² , Fisher's exact, and Mann-Whitney U tests were applied, using SPSS software (v.23).

RESULTS

Twenty-nine HIV subjects (median age 38 years, 93% males) were included. Most were AIDS individuals (72.4%) under HAART (89.7%). Twenty-two (75.9%) participants had more than one HPV-OL (four with florid presentations), mostly multifocal epithelial hyperplasia (62%), being HPV-13 (26%) and HPV-32 (31%) the most frequent types. HPV load was higher in individuals with multiple HPV-OLs than in solitary lesions (4.9 vs. 3.2 Log₁₀ copies/ml, p = .090) and in HPV-32⁺ than in HPV-13⁺ (8.3 vs. 6.4 Log₁₀ copies/ml, p = .014).

CONCLUSIONS

Multiple HPV-OLs showed high HPV loads, possibly indicating transcriptional activity of the virus; however, in the HIV setting, the individual and local immunological response could be the key process.

Expanded strain coverage for a highly successful public health tool: Prophylactic 9-valent human papillomavirus vaccine

Human papillomavirus is considered the causative factor for cervical cancer, which accounts for approximately 5% of the global cancer burden and more than 600,000 new cases annually that are attributable to HPV infection worldwide. The first-generation prophylactic HPV vaccines, Gardasil® and Cervarix®, were licensed approximately a decade ago. Both vaccines contain the most prevalent high-risk types, HPV16 and 18, which are associated with 70% of cervical cancer. To further increase the type coverage, 5 additional oncogenic HPV types (31, 33, 45, 52 and 58) were added to the existing Gardasil-4 to develop a 9-valent HPV vaccine (9vHPV), Gardasil 9®, increasing the potential level of protection from ∼70% to ∼90%. The efficacy of the vaccine lies primarily in its ability to elicit type-specific and neutralizing antibodies to fend off the viral infection. Therefore, type-specific and neutralizing murine monoclonal antibodies (mAbs) were used to quantitate the antigenicity of the individual vaccine antigens and to measure the antibody levels in the serum samples from vaccinees in a type- and epitope-specific manner in a competitive immunoassay. Assays for 9vHPV are extended from the proven platform used for 4vHPV by developing and adding new mAbs against the additional types. In Phase III clinical trials, comparable safety profile and immunogenicity against the original 4 types were demonstrated for the 9vHPV vaccine, and these were comparable to the 4vHPV vaccine. The efficacy of the 9vHPV vaccine was established in trials with young women. Immunobridging for younger boys and girls was performed, and the results showed higher immunogenicity in the younger age group. In a subsequent clinical trial, the 2-dose regimen of the 9vHPV vaccine used among girls and boys aged 9-14 y showed non-inferior immunogenicity to the regular 3-dose regimen for young women (aged 16-26 years). Overall, the clinical data and cost-effectiveness analysis for the 9vHPV vaccine support its widespread use to maximize the impact of this important, life-saving vaccine.

Factors that Predict Parental Willingness to Have Their Children Vaccinated against HPV in a Country with Low HPV Vaccination Coverage

Background: Adolescent HPV (Human Papilloma Virus) vaccination is yet to be introduced as a mandatory program in Poland. Polish literature on factors associated with adolescent HPV vaccination is scant, despite the fact that uptake is one of the poorest in the European Union. Objectives: To assess HPV awareness and identify independent predictors for parental willingness to have their children vaccinated against HPV. Methods: All parents of first grade students from three selected high schools in Zgorzelec, Poland, who participated in parent–teacher meetings at the time the study was conducted, had their children unvaccinated regarding HPV, and who gave informed consent to participate were included. There were 600 first grade students; 9 were vaccinated against HPV. This left 591 parents who met the eligibility criteria; the response rate was 76.1%. Results: Awareness of HPV was reported by 55.3% of 450 parents (mean age 42 years, 70.9% females); 85.1% expressed their willingness to vaccinate their children against HPV; 31.3% identified HPV as a sexually transmitted pathogen, and 36.2% identified it as a risk factor of cervical cancer. Multivariable logistic regression analyses indicated that being employed (OR 2.09; 95% CI: 1.10–3.86), having positive attitudes toward vaccines (OR 3.02; 95% CI: 1.34–6.49), previous information about HPV (OR 2.02; 95% CI: 1.17–3.51), and concerns about the side effects of the HPV vaccine (OR 0.60; 95% CI: 0.35–0.99) were independent predictors of parents’ willingness to vaccinate. Conclusions: Attitudes regarding their child being vaccinated against HPV were positive among Polish parents, even though awareness and knowledge of HPV in this group were low. Most of the significant factors that influenced their willingness were modifiable, such as being informed about HPV and having positive attitudes toward vaccines. Future interventions should focus specifically on vulnerable subgroups, such as unemployed parents.

Cidofovir is active against human papillomavirus positive and negative head and neck and cervical tumor cells by causing DNA damage as one of its working mechanisms

Human papillomavirus (HPV) causes cervical cancer and a large fraction of head and neck squamous cell carcinomas (HNSCC). Cidofovir (CDV) proved efficacious in the treatment of several HPV-induced benign and malignant hyper proliferations. To provide a better insight into how CDV selectively eradicates transformed cells, HPV+ and HPV- cervical carcinoma and HNSCC cell lines were compared to normal cells for antiproliferative effects, CDV metabolism, drug incorporation into cellular DNA, and DNA damage. Incorporation of CDV into cellular DNA was higher in tumor cells than in normal cells and correlated with CDV antiproliferative effects, which were independent of HPV status. Increase in phospho-ATM levels was detected following CDV exposure and higher levels of γ-H2AX (a quantitative marker of double-strand breaks) were measured in tumor cells compared to normal cells. A correlation between DNA damage and CDV incorporation into DNA was found but not between DNA damage and CDV antiproliferative effects. These data indicate that CDV antiproliferative effects result from incorporation of the drug into DNA causing DNA damage. However, the anti-tumor effects of CDV cannot be exclusively ascribed to DNA damage. Furthermore, CDV can be considered a promising broad spectrum anti-cancer agent, not restricted to HPV+ lesions.

Inhibition of Human Papillomavirus Type 16 Infection Using an RNA Aptamer

Human papillomavirus type 16 (HPV16) DNA has been found in ∼50% of cervical tumors worldwide. HPV infection starts with the binding of the virus capsid to heparan sulfate (HS) receptors exposed on the surface of epithelial basal layer keratinocytes. Previously, our group isolated a high-affinity RNA aptamer (Sc5c3) specific for HPV16 L1 virus-like particles (VLPs). In this study, we report the inhibition of HPV16 infection by Sc5c3 in a pseudovirus (PsVs) model. 293TT cells were infected by HPV16 PsVs containing the yellow fluorescent protein (YFP) as reporter gene. Incubation of HPV16 PsVs with Sc5c3 before infection resulted in a dose-dependent decrease in YFP fluorescence, suggesting infection inhibition. Aptamer degradation by RNase A restored PsVs infectivity, supporting the previous observation that Sc5c3 aptamer can inhibit infection. VLP mutants with removed HS binding sites were used in binding assays to elucidate the Sc5c3 blocking mechanism; however, no binding difference was observed between wild-type and mutant VLPs, suggesting that pseudoinfection inhibition relies on mechanisms additional to electrostatic HS binding site interaction. A DNA/RNA Sc5c3 version also inhibited HPV PsVs infection, suggesting that a modified, nuclease-resistant Sc5c3 may be used to inhibit HPV16 infection in vivo.

Investigating Canadian parents' HPV vaccine knowledge, attitudes and behaviour: a study protocol for a longitudinal national online survey

INTRODUCTION

Human papillomavirus (HPV), a sexually transmitted infection, can cause anogenital warts and a number of cancers. To prevent morbidity and mortality, three vaccines have been licensed and are recommended by Canada's National Advisory Committee on Immunisation (for girls since 2007 and boys since 2012). Nevertheless, HPV vaccine coverage in Canada remains suboptimal in many regions. This study will be the first to concurrently examine the correlates of HPV vaccine decision-making in parents of school-aged girls and boys and evaluate changes in parental knowledge, attitudes and behaviours over time.

METHODS AND ANALYSIS

Using a national, online survey utilising theoretically driven constructs and validated measures, this study will identify HPV vaccine coverage rates and correlates of vaccine decision-making in Canada at two time points (August-September 2016 and June-July 2017). 4606 participants will be recruited to participate in an online survey through a market research and polling firm using email invitations. Data cleaning methods will identify inattentive or unmotivated participants.

ETHICS AND DISSEMINATION

The study received research ethics board approval from the Research Review Office, Integrated Health and Social Services University Network for West-Central Montreal (CODIM-FLP-16-219). The study will adopt a multimodal approach to disseminate the study's findings to researchers, clinicians, cancer and immunisation organisations and the public in Canada and internationally.

Universal proposal strategies of anti-HPV vaccination for adolescents: comparative analysis between school-based and clinic immunization programs

INTRODUCTION

A promising approach to increase teenager's adherence to immunization against HPV is the administration of vaccinations within the school facilities. The Local Health Unit of Taranto experienced two different vaccine strategy proposals in the twelve-year-olds: the first one was the usual active call strategy in the outpatient clinic, while the second one provided the involvement of the schools in the area. The aim of the study is to evaluate the results of the proposed vaccination strategies in both sexes and in towns of different sizes in order to identify an effective path for achieving vaccine coverage improvement.

METHODS

To estimate the number of anti-HPV vaccine doses administered in adolescents of the 2003 cohort, we used the computerized vaccination system data of the Apulia Region. Then, once analyzed, the data for anti-HPV vaccine were broken down by gender, vaccine strategy and size of the town of residence. Analyses performed by using STATA SE 14.

RESULTS

The multiple logistic regression points out that, females (OR = 3.2; p < 0.01), living in small towns (OR = 1.3; p < 0.01) and school vaccination strategy (OR = 2; p < 0.01) increase the likelihood of completing the anti-HPV vaccine cycle in adolescents. The comparative assessment of anti-HPV coverage strategies, suggests that school vaccination has resulted in significantly better outcomes than outpatient clinic one, for all the groups considered (overall 72.3% vs 55.6%).

CONCLUSIONS

The involvement of school institutes can define a winning organizational model to get a wider adolescent's adherence to immunization programs, especially in bigger towns. The school vaccination strategy could improve anti-HPV vaccine adherence also in males, who perceives a lower HPV-related diseases risk than females.

ERAP1 overexpression in HPV-induced malignancies: A possible novel immune evasion mechanism

Immune evasion of tumors poses a major challenge for immunotherapy. For human papillomavirus (HPV)-induced malignancies, multiple immune evasion mechanisms have been described, including altered expression of antigen processing machinery (APM) components. These changes can directly influence epitope presentation and thus T-cell responses against tumor cells. To date, the APM had not been studied systematically in a large array of HPV⁺ tumor samples. Therefore in this study, systematic expression analysis of the APM was performed on the mRNA and protein level in a comprehensive collection of HPV16⁺ cell lines. Subsequently, HPV⁺ cervical tissue samples were examined by immunohistochemistry. ERAP1 (endoplasmic reticulum aminopeptidase 1) was the only APM component consistently altered - namely overexpressed - in HPV16⁺ tumor cell lines. ERAP1 was also found to be overexpressed in cervical intraepithelial neoplasia and cervical cancer samples; expression levels were increasing with disease stage. On the functional level, the influence of ERAP1 expression levels on HPV16 E7-derived epitope presentation was investigated by mass spectrometry and in cytotoxicity assays with HPV16-specific T-cell lines. ERAP1 overexpression did not cause a complete destruction of any of the HPV epitopes analyzed, however, an influence of ERAP1 overexpression on the presentation levels of certain HPV epitopes could be demonstrated by HPV16-specific CD8⁺ T-cells. These showed enhanced killing toward HPV16⁺ CaSki cells whose ERAP1 expression had been attenuated to normal levels. ERAP1 overexpression may thus represent a novel immune evasion mechanism in HPV-induced malignancies, in cases when presentation of clinically relevant epitopes is reduced by overactivity of this peptidase.

Immunogenicity and safety of human papillomavirus (HPV) vaccination in Asian populations from six countries: a meta-analysis

Cervical cancer is a serious public-health problem in Asian countries. Since human papillomavirus (HPV) infection is the main risk factor for cervical cancer, HPV vaccination is considered a promising strategy to prevent cervical cancer. However, comprehensive immunogenicity and safety information for Asian populations is lacking. We searched four electronic databases including PubMed, EMBASE, Cochrane Library, and clinicaltrials.gov. We reviewed selected manuscripts and extracted the pooled relative risk (RR) from immunogenicity and safety information on HPV vaccination among women in Asian countries. We identified two quadrivalent-vaccine studies and eight bivalent-vaccine studies conducted in Asian countries. Analysis across these studies suggested that the HPV vaccines significantly enhanced HPV16- and HPV18-specific antibody among both uninfected (RR 85.69; 95% confidence interval (CI) 31.51-233.04 and 62.77; 95% CI 37.4-105.51) and infected individuals (RR 8.60; 95% CI 6.95-10.64 and RR 8.13; 95% CI 5.96-11.11). Furthermore, HPV vaccination among Asian populations has a favorable safety profile, with only slightly higher risks of local (RR: 1.89; 95% CI 1.65-2.17) and systemic (RR: 1.33; 95% CI 1.18-1.50) adverse events in vaccinated individuals compared with controls. For Asian populations, HPV vaccines enhance the level of HPV16- and HPV18-specific antibodies for both uninfected and infected individuals. Also, the risk of adverse events related to vaccination are acceptable. More data are needed to establish vaccine efficacy with regard to prevention of HPV infection and further outcomes including cervical intraepithelial neoplasia (CIN) and cervical cancer.

Ranpirnase eradicates human papillomavirus in cultured cells and heals anogenital warts in a Phase I study

BACKGROUND

Human papillomaviruses (HPV), the causative agents of anogenital warts, are the most prevalent sexually transmitted infectious agents, and wart treatment poses a persistent challenge. We assessed the safety and efficacy of treating HPV with ranpirnase, an endoribonuclease from the northern leopard frog that has been used extensively in Phase III oncology trials.

METHODS

As initial verification of ranpirnase antiviral activity, we assessed its ability to eliminate papillomaviruses in cultured cells. To further assess its feasibility for treating anogenital warts in humans, we performed a Phase I study. Forty-two male volunteers with genital/perianal warts were treated topically with three different formulations of 1 mg/ml ranpirnase. Patients were monitored for 8 weeks or until healing. Four patients with HIV were treated in accordance with the compassionate programme but were not evaluated.

RESULTS

In cultured cells, ranpirnase showed specific activity against HPV-11 with low toxicity (selectivity index >88). The broad applicability of ranpirnase for treating papillomaviruses was verified using the cottontail rabbit papillomavirus. In the clinical study, eight participants were lost-to-follow-up or discontinued due to protocol violation or non-compliance. Among 30 evaluable participants, topical ranpirnase was moderately well-tolerated, with discontinuation by 5 (16.7%) due to adverse reactions. Clinical healing was achieved by 25 participants (83.3%) and 50% improvement by the 5 discontinued participants (16.7%). The median time to clinical healing was 30 days.

CONCLUSIONS

This study provides the first in vitro and clinical evidence of the antiviral efficacy of ranpirnase against HPV and supports assessment of ranpirnase in expanded clinical studies.

Detection of human papillomavirus infection by molecular tests and its relation to colonic polyps and colorectal cancer

Objectives:

To prospectively examine the association between human papilloma virus (HPV) colonization of the colonic mucosa and the development of colorectal polyps (CRPs), and colorectal cancer (CRC) in Saudi Arabia.

Methods:

A case control study was performed between January 2013 and December 2014. All eligible patients underwent standard diagnostic colonoscopy. Patients with polyps or colorectal cancer were considered cases, while those with any other endoscopic findings were controls. Biopsy samples from polyps and tumors, and/or from normal colonic mucosa were acquired. Human papilloma virus colonization was detected using a hybrid capture technique of samples taken from both normal tissue, and CRPs and CRC. The association between HPV and CRPs/CRC was evaluated.

Results:

A total of 132 patients were recruited. The mean age was 53 (±15.9) years. Sixty patients had endoscopically detectable CRPs/CRC, and 72 had either inflammation or normal endoscopic evaluations. Only 4 (0.8%) of the 132 samples that were collected and analyzed were positive for the HPV gene. Statistical analysis did not identify any significant association between HPV colonization and the presence of CRPs/CRC. The only significant predictor of detecting CRPs/CRC on colonoscopy was symptomatic presentation (odds ratio=11.072, 95% confidence interval 4.7-26.2, p<0.001).

Conclusion:

Human papilloma virus colonic colonization is rare in Saudi Arabia. An association between HPV colonization and CRP/CRC development could not be identified in this cohort of patients.

Overview of the benefits and potential issues of the nonavalent HPV vaccine

HPV-related diseases affect anogenital and oropharyngeal regions, heavily affecting the psychosexual dimension of both male and female individuals. HPV vaccination programs based on a bivalent or quadrivalent vaccine have opened broad perspectives for primary prevention. A nonavalent HPV vaccine (9vHPV), covering nine genotypes (HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58), might provide further improvement in terms of direct protection. In the present report, efficacy and safety data from 9vHPV vaccine development programs are examined. Efficacy data come from a pivotal trial, which was conducted among women aged 16-26 years randomly assigned to receive either the 9vHPV or the quadrivalent HPV (4vHPV) vaccine. The 9vHPV vaccine was shown to have potential benefits as compared with 4vHPV, increasing the overall estimated rate of prevention to 90% for cervical cancer and up to 80% for precancerous cervical lesions. For all other HPV-related pre-invasive and invasive lesions, 9vHPV showed potentially greater disease reduction, depending on the anatomic region examined. Thus, the 9vHPV vaccine shows clinical potential for the prevention of HPV-related diseases in both sexes. Future adoption of 9vHPV will depend on factors including market price, cost-effectiveness data, use of a two-dose schedule, and safety and efficacy monitoring in real-life programs.

How Much Do Italian Patients in Supportive Periodontal Therapy Know about the Role of Smoking in Oral Health and What is Their Lifestyle?

OBJECTIVE

The level of awareness of patients receiving supportive periodontal therapy (SPT) concerning the role of smoking as a risk factor for oral health was investigated.

MATERIALS AND METHODS

A questionnaire was administered to 158 patients previously treated for periodontitis in four periodontally oriented private dental offices in Rome. The generalized linear model was used to test the simultaneous effect of questions posed to all patients. Fisher's exact test was used to verify significant associations among qualitative variables.

RESULTS

Only 53.79% of the total sample referred having been informed by the dentist/hygienist about smoking as an oral health risk factor. About 40% of patients did not know that oral cancer exists and only 36.08% of them reported being informed about it by their own dentist/hygienist. Females are significantly less frequent among ex-smokers than among smokers. Nonsmokers were on periodontal supportive therapy for a longer period than smokers. Patients who started smoking later found harder to quit smoking than those who started earlier.

CONCLUSION

Awareness of patients in SPT about health risks related to smoking does not assume a change in their harmful behavior. Among oral health professionals, there is not yet a widespread awareness of the importance of their role in increasing patient's motivation to quit.

Human papillomavirus molecular biology

Human papillomaviruses are small DNA viruses with a tropism for squamous epithelia. A unique aspect of human papillomavirus molecular biology involves dependence on the differentiation status of the host epithelial cell to complete the viral lifecycle. A small group of these viruses are the etiologic agents of several types of human cancers, including oral and anogenital tract carcinomas. This review focuses on the basic molecular biology of human papillomaviruses.

Cancer Vaccines: Past, Present, and Future

Cancer is a common and potentially deadly disease. Some of the cancers may be difficult to treat by conventional means such as surgery, radiation, and chemotherapy, but may be controlled by the stimulation of the immune response of the body with the help of cancer vaccines. The use of vaccines for preventing infections by oncogenic viruses such as hepatitis B virus and human papilloma virus has been extremely successful in reducing the incidence of cancers resulting from these infections. The use of vaccines for treating cancers that are not due to viral infections and that are already established is currently the object of numerous clinical trials. Several types of cancer vaccines are being tried. These include antigen vaccines, tumor cell vaccines, dendritic vaccines, deoxyribonucleic acid vaccines, and viral vector vaccines. The development of these therapeutic vaccines is proving difficult with only 1 recent success. However, there is significant enthusiasm and optimism regarding the development of effective therapeutic vaccines stemming from the fact that our understanding regarding the cancer immunology is considerably enhanced in recent years. This expanded knowledge regarding the mechanisms that cancers use to escape the immune system is likely to open new avenues in modulating the immune response to cancer, thus enhancing the effectiveness of therapeutic cancer vaccines.

CCR2 and CCR5 genes polymorphisms in women with cervical lesions from Pernambuco, Northeast Region of Brazil: a case-control study

Polymorphisms in chemokine receptors play an important role in the progression of cervical intraepithelial neoplasia (CIN) to cervical cancer (CC). Our study examined the association of CCR2-64I (rs1799864) andCCR5-Δ32 (rs333) polymorphisms with susceptibility to develop cervical lesion (CIN and CC) in a Brazilian population. The genotyping of 139 women with cervical lesions and 151 women without cervical lesions for the CCR2-64I and CCR5-Δ32 polymorphisms were performed using polymerase chain reaction-restriction fragment length polymorphism. The individuals carrying heterozygous or homozygous genotypes (GA+AA) for CCR2-64I polymorphisms seem to be at lower risk for cervical lesion [odds ratio (OR) = 0.37, p = 0.0008)]. The same was observed for the A allele (OR = 0.39, p = 0.0002), while no association was detected (p > 0.05) with CCR5-Δ32 polymorphism. Regarding the human papillomavirus (HPV) type, patients carrying the CCR2-64Ipolymorphism were protected against infection by HPV type 16 (OR = 0.35, p = 0.0184). In summary, our study showed a protective effect ofCCR2-64I rs1799864 polymorphism against the development of cervical lesions (CIN and CC) and in the susceptibility of HPV 16 infection.

Effect of vaccination age on cost-effectiveness of human papillomavirus vaccination against cervical cancer in China

Background

The cost-effectiveness of human papillomavirus (HPV) vaccination in women pre-sexual debut has been demonstrated in many countries. This study aimed to estimate the cost-effectiveness of a 3-dose bivalent HPV vaccination at ages 12 to 55 year in both rural and urban settings in China.

Methods

The Markov cohort model simulated the natural history of HPV infection and included the effect of screening and HPV vaccination over the lifetime of a 100,000 female cohort. Transition probabilities and utilities were obtained from published literature. Cost data were estimated by Delphi panel using healthcare payers’ perspective. Vaccine cost was assumed Hong Kong listed price. Vaccine efficacy (VE) was based on the PATRICIA trial data assuming VE irrespective of HPV type at all ages on incident HPV. Costs and outcomes were discounted at 3 %. Cervical cancer cases and incremental cost-effectiveness ratio (ICER) for vaccination and screening compared with screening alone were estimated for each vaccination age. Reduced VE in women post-sexual debut were investigated in scenario analyses.

Results

With 70 % vaccination coverage, a reduction of cancer cases varying from 585 to 33 in rural and 691 to 32 in urban were estimated at ages 12 to 55, respectively. The discounted ICERs of vaccination at any age under 23 years in rural and any age under 25 years in urban were lower than the current threshold. Scenario analyses with lower VE post-sexual debut confirmed the results with age 20 in rural and 21 in urban had consistent lower ICERs. The more ‘catch-up’ cohorts vaccinated at the start of a program, the more cancer lesions are avoided in the long-term.

Conclusions

Vaccination at any age under 23 years old in rural and any age under 25 years old in urban were cost-effective. Catch-up to the age of 25 years in rural and urban could still be cost-effective.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2207-3) contains supplementary material, which is available to authorized users.

Human papillomavirus vaccine trials and tribulations: Vaccine efficacy

As of December 2014, there were 3 approved vaccines for human papillomavirus (HPV): bivalent Cervarix (GlaxoSmithKline, New York, NY), quadrivalent Gardasil (Merck and Co, Kenilworth, NJ), and 9-valent Gardasil-9 (Merck and Co). The average cost per dose is $120, with a recommended 3-dose course. The quadrivalent vaccine is the most widely administered worldwide. As with the bivalent and 9-valent vaccines, the vaccine is considered safe, although concerns have been raised. In addition to immunization against the targeted HPV types, there is evidence that there is cross protection against other types of HPV. This continuing medical education review evaluates the differences in vaccines that are currently on the market; part II focuses on the cost-effectiveness of vaccination, the HPV vaccination programs currently instituted around the globe, efficacy, and safety.

HPV vaccination: acceptance and influencing factors among young men in Germany

AIMS

This study aims to determine the factors that influence the acceptance of the HPV vaccination among German males.

PATIENT & METHODS

In 2014, we conducted a population-based cross-sectional study in men aged 15-25 years. A questionnaire was mailed to male trainees of the Bayerische Motorenwerke AG (BMW) insured at the BMW health insurance company.

RESULTS

The response rate was 10.8%. Of the 378 included men, 74.1% would agree to receive HPV vaccination. Most men primarily consult their physician for health-related topics, but 92.9% had never been informed about HPV infection, risk factors and prevention methods by their doctor.

CONCLUSION

Our results demonstrate a high acceptance of male HPV vaccination. Education about HPV infection is low and should be intensified by medical professionals.

HPV vaccination for MSM: Synthesis of the evidence and recommendations from the Québec Immunization Committee

Diseases associated with the human papilloma virus (HPV) are particularly common among men who have sex with men (MSM). Unlike heterosexual men, MSM do not benefit from the herd protection provided by the vaccination of girls. In this review, we synthesize the available evidence on HPV vaccination for MSM. We also present the recommendations of the Québec Immunization Committee (CIQ) in this regard, which are: to provide targeted vaccination for MSM up to 26 years of age and in-school vaccination of preadolescent boys since this is the best approach to take to have a real impact on the burden related to HPV in the MSM population and to provide direct protection for all men.