Next Generation Cancer Protection: The Bivalent HPV Vaccine for Females

Distribution of Human Papillomavirus (HPV) Genotypes in HIV-Negative and HIV-Positive Women with Cervical Intraepithelial Lesions in the Eastern Cape Province, South Africa

South African women have a high rate of cervical cancer cases, but there are limited data on human papillomavirus (HPV) genotypes in cervical intraepithelial neoplasia (CIN) in the Eastern Cape province, South Africa. A total of 193 cervical specimens with confirmed CIN from women aged 18 years or older, recruited from a referral hospital, were tested for HPV infection. The cervical specimens, smeared onto FTA cards, were screened for 36 HPV types using an HPV direct flow kit. HPV prevalence was 93.5% (43/46) in CIN2 and 96.6% (142/147) in CIN3. HIV-positive women had a significantly higher HPV prevalence than HIV-negative women (98.0% vs. 89.1%, p = 0.012). The prevalence of multiple types was significantly higher in HIV-positive than HIV-negative women (p = 0.034). The frequently detected genotypes were HPV35 (23.9%), HPV58 (23.9%), HPV45 (19.6%), and HPV16 (17.3%) in CIN2 cases, while in CIN3, HPV35 (22.5%), HPV16 (21.8%), HPV33 (15.6%), and HPV58 (14.3%) were the most common identified HPV types, independent of HIV status. The prevalence of HPV types targeted by the nonavalent HPV vaccine was 60.9% and 68.7% among women with CIN2 and CIN3, respectively, indicating that vaccination would have an impact both in HIV-negative and HIV-positive South African women, although it will not provide full protection in preventing HPV infection and cervical cancer lesions.

Cervical Dysplasia, Infection, and Phylogeny of Human Papillomavirus in HIV-Infected and HIV-Uninfected Women at a Reproductive Health Clinic in Nairobi, Kenya

High risk human Papillomavirus (HPV) infections ultimately cause cervical cancer. Human Immunodeficiency Virus (HIV) infected women often present with multiple high-risk HPV infections and are thus at a higher risk of developing cervical cancer. However, information on the circulating high-risk HPV genotypes in Kenya in both HIV-infected and HIV-uninfected women is still scanty. This study is aimed at determining the phylogeny and the HPV genotypes in women with respect to their HIV status and at correlating this with cytology results. This study was carried out among women attending the Reproductive Health Clinic at Kenyatta National Hospital, a referral hospital in Nairobi, Kenya. A cross-sectional study recruited a total of 217 women aged 18 to 50 years. Paired blood and cervical samples were obtained from consenting participants. Blood was used for serological HIV screening while cervical smears were used for cytology followed by HPV DNA extraction, HPV DNA PCR amplification, and phylogenetic analysis. Out of 217 participants, 29 (13.4%) were HIV seropositive, while 68 (31.3%) were positive for HPV DNA. Eight (3.7%) of the participants had abnormal cervical cytology. High-risk HPV 16 was the most prevalent followed by HPV 81, 73, 35, and 52. One participant had cervical cancer, was HIV infected, and had multiple high-risk infections with HPV 26, 35, and 58. HPV 16, 6, and 81 had two variants each. HPV 16 in this study clustered with HPV from Iran and Africa. This study shows the circulation of other HPV 35, 52, 73, 81, 31, 51, 45, 58, and 26 in the Kenyan population that play important roles in cancer etiology but are not included in the HPV vaccine. Data from this study could inform vaccination strategies. Additionally, this data will be useful in future epidemiological studies of HPV in Nairobi as the introduction or development of new variants can be detected.

Reduced rate of human papillomavirus infection and genetic overtransmission of TP53 72C polymorphic variant lower cervical cancer incidence

BACKGROUND

Cervical cancer is a predominantly human papillomavirus (HPV)‐driven disease worldwide. However, its incidence is unexplainably low in western Asia, including Saudi Arabia. Using this paradigm, we investigated the role of HPV infection rate and host genetic predisposition in TP53 G72C single nucleotide polymorphism (SNP) presumed to affect cancer incidence.

METHODS

Patients treated between 1990 and 2012 were reviewed, and a series of 232 invasive cervical cancer cases were studied and compared with 313 matched controls without cancer. SNP was genotyped by way of direct sequencing. HPV linear array analysis was used to detect and genotype HPV in tumor samples.

RESULTS

The incidence of cervical cancer revealed bimodal peaks at 42.5 years, with a slighter rebound at 60.8 years. Among all cases, 77% were HPV‐positive and 16 HPV genotypes were detected—mostly genotypes 16 (75%) and 18 (9%)—with no difference by age, histology, or geographical region. Although the TP53 G72C genotype was not associated with overall cervical cancer risk, it was significantly associated with HPV positivity (odds ratio, 0.57; 95% confidence interval, 0.36‐0.90; P = .016). Furthermore, the variant C allele was significantly overtransmitted in the population (P < .0003).

CONCLUSION

Cervical cancer incidence displays bimodal curve peaking at a young age with secondary rebound at older age. The combination of relative low HPV infection and variant TP53 72C allele overtransmission provide a plausible explanation for the low incidence of cervical cancer in our population. Therefore, HPV screening and host SNP genotyping may provide more relevant biomarkers to gauge the risk of developing cervical cancer. Cancer 2017;123:2459–66. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Cervical cancer incidence shows bimodal peaks at 43 years and relative rebound at 61 years of age. A reduced rate of human papillomavirus infection and overtransmission of the TP53 72C variant lower cancer incidence.

[Vaccines as an agent for immunization against HPV]

Considered a highly prevalent infection throughout the world, the human papillomavirus (HPV) is a DNA virus that infects the genital mucosa and has high carcinogenic potential, being related to an increased risk of lower genital tract lesions, such as cervical cancer. This cancer is responsible for the deaths of about 231,000 women per year worldwide, which means that HPV is a major problem for public health. Knowing that the most effective and cost-effective way to control an infectious disease is the development of vaccines, two prophylactic vaccines have been developed and approved in Brazil, one of which is bivalent and the other is tetravalent. This review of the literature seeks to present the characteristics of the HPV virus, types of vaccines available on the market, their indications and contraindications, their adverse effects, their effectiveness, their geometric mean titer (GMT) and their cost-effectiveness.

A literature review on the patients with autoimmune diseases following vaccination against infections

Due to immune abnormalities and the use of steroids and immunosuppressant treatment, patients with rheumatic diseases are susceptible to infections. Vaccination is one of the most important prevention tools in modern medicine. A discussion on risk-benefit or cost-benefit analysis, and advisory on individual vaccines or vaccination programs falls outside the scope of this review. In particularly, this review summarizes the knowledge about the effectiveness and safety vaccinations in patients with autoimmune inflammatory rheumatic diseases (AIIRD) treated with biologics. Finally, we aim to provide vaccination plans basis for clinical management of rheumatic patients depending upon prevaccination antibody titers, drug treatments and immunological potential.

Development of a schistosomiasis vaccine

Schistosomiasis is a neglected tropical disease (NTD) of public health importance. Despite decades of implementation of mass praziquantel therapy programs and other control measures, schistosomiasis has not been contained and continues to spread to new geographic areas. A schistosomiasis vaccine could play an important role as part of a multifaceted control approach. With regards to vaccine development, many biological bottlenecks still exist: the lack of reliable surrogates of protection in humans; immune interactions in co-infections with other diseases in endemic areas; the potential risk of IgE responses to antigens in endemic populations; and paucity of appropriate vaccine efficacy studies in nonhuman primate models. Research is also needed on the role of modern adjuvants targeting specific parts of the innate immune system to tailor a potent and protective immune response for lead schistosome vaccine candidates with the long-term aim to achieve curative worm reduction. This review summarizes the current status of schistosomiasis vaccine development.

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.

Current status of human papillomavirus vaccines

Cervical cancer is a malignant neoplasm arising from cells that originate in the cervix uteri. It is the second most prevalent cancer among women. It can have several causes; an infection with some type of human papillomavirus (HPV) is the greatest risk factor for cervical cancer. Over 100 types of HPVs have been identified, and more than 40 types of HPVs are typically transmitted through sexual contact and infect the anogenital region. Among these, a number of HPVs types, containing types 16 and 18, are classified as "high-risk" HPVs that can cause cervical cancer. The HPVs vaccine prevents infection with certain species of HPVs associated with the development of cervical cancer, genital warts, and some less common cancers. Two HPVs vaccines are currently on the global market: quadrivalent HPVs vaccine and bivalent HPV vaccine that use virus-like particles as a vaccine antigen. This review discusses the current status of HPVs vaccines on the global market, clinical trials, and the future of HPVs vaccine development.

Intent to participate in future cervical cancer screenings is lower when satisfaction with the decision to be vaccinated is neutral

BACKGROUND

HPV vaccination programs have adversely affected participation in future cervical cancer screening. The purpose of this study is to determine the influence of decision satisfaction with accepting/rejecting the HPV vaccine, as well as traditional clinical factors, on the intent to participate in future screening.

METHODS AND FINDINGS

From January 2011 through August 2012 women 18-26 years old presenting for health care in an urban college student health and wellness clinic in the US Midwest were asked to complete a descriptive and medical history survey including a six element decisional satisfaction survey scored on 5-point Likert scales, where the intent to participate in future cervical cancer screening was measured. Of the 568 women who completed the decisional satisfaction survey, 17% of those <21 years and 7% ≥ 21 years indicated no intent to participate in future cervical cancer screenings. Among women of current screening age, the univariate risk factors of race/ethnicity, contraceptive use, number of lifetime sexual partners, and receipt of HPV vaccine were not predictors of intent for future cervical cancer screening. Instead, only a history of a prior Pap test was a significant positive predictor and only a decisional satisfaction of 'neutral' (Likert score = 3) for any of the four decisional satisfaction elements was a significant negative predictor. For the decisional satisfaction element "best for me personally", there was a 78% decreased likelihood of intending to participate in future screening if the satisfaction was neutral rather than firm (aOR = 0.22, 95% CI: 0.05-0.91) and a 26 fold increased likelihood if she had had a prior Pap test (aOR = 26, 95% CI: 5-133).

CONCLUSIONS

HPV vaccination implementation programs must help women be the owner of their decision around HPV vaccination and understand the importance of future participation in cervical cancer screening.

Urban and rural safety net health care system clinics: no disparity in HPV4 vaccine completion rates

OBJECTIVE

Safety net health care centers in the US serve vulnerable and underinsured females. The primary aim of this work was to determine if HPV4 dosing compliance differs between females who receive doses at rural vs. urban core safety net health care locations.

METHODS

Females exclusively receiving health care in the Truman Medical Center (TMC) safety net system at the urban core and rural locations were identified by their HPV4 vaccine records. Dates and number of HPV4 doses as well as age, gravidity, parity and race/ethnicity were recorded from the electronic medical record (EMR). Appropriate HPV4 dosing intervals were referenced from the literature.

RESULTS

1259 females, 10-26 years of age, received HPV4 vaccination at either the rural (23%) or urban core location (77%). At the rural location, 23% received three doses on time, equal to the 24% at the urban core. Females seen in the urban core were more likely to receive on-time doublet dosing than on-time triplet dosing (82% vs. 67%, p<0.001). Mistimed doses occurred equally often among females receiving only two doses, as well as those receiving three doses.

CONCLUSIONS

Compliance with on-time HPV4 triplet dose completion was low at rural and urban core safety net health clinics, but did not differ by location.

A nanoliposome delivery system to synergistically trigger TLR4 AND TLR7

Background

Recent reports that TLR4 and TLR7 ligands can synergistically trigger Th1 biased immune responses suggest that an adjuvant that contains both ligands would be an excellent candidate for co-administration with vaccine antigens for which heavily Th1 biased responses are desired. Ligands of each of these TLRs generally have disparate biochemical properties, however, and straightforward co-formulation may represent an obstacle.

Results

We show here that the TLR7 ligand, imiquimod, and the TLR4 ligand, GLA, synergistically trigger responses in human whole blood. We combined these ligands in an anionic liposomal formulation where the TLR7 ligand is in the interior of the liposome and the TLR4 ligand intercalates into the lipid bilayer. The new liposomal formulations are stable for at least a year and have an attractive average particle size of around 140 nm allowing sterile filtration. The synergistic adjuvant biases away from Th2 responses, as seen by significantly reduced IL-5 and enhanced interferon gamma production upon antigen-specific stimulation of cells from immunized mice, than any of the liposomal formulations with only one TLR agonist. Qualitative alterations in antibody responses in mice demonstrate that the adjuvant enhances Th1 adaptive immune responses above any adjuvant containing only a single TLR ligand as well.

Conclusion

We now have a manufacturable, synergistic TLR4/TLR7 adjuvant that is made with excipients and agonists that are pharmaceutically acceptable and will have a straightforward path into human clinical trials.

Factors associated With Medicaid providers' recommendation of the HPV vaccine to low-income adolescent girls

PURPOSE

Human papillomavirus (HPV) vaccination in the United States remains a public health challenge with vaccine rates of 50%. Although health care providers can facilitate HPV vaccination, several factors may impede their ability to universally recommend the vaccine. To maximize the potential of HPV vaccines, it is important to understand challenges providers face in the clinical environment. The study sought to identify factors associated with recommendation of the HPV vaccine for low-income adolescents in the early (9-10), target (11-12), early adolescent catch-up (13-14), and late adolescent catch-up (15-17) vaccination groups.

METHODS

Surveys were mailed between October 2009 and April 2010 to a random sample of Florida-based physicians serving Medicaid-enrolled adolescents. Data were analyzed in 2013.

RESULTS

Among early adolescents, discomfort discussing sexually transmitted infections (STIs) with teens (odds ratio [OR] = 1.75), difficulty ensuring vaccine completion (OR = .73), and discomfort discussing STIs with parents (OR = .44) were associated with recommendation. For target adolescents, discomfort discussing STIs with teens (OR = 2.45), time constraints (OR = .70), vaccine efficacy concerns (OR = .65), discomfort discussing STIs with parents (OR = .33), obstetrics/gynecology (OR = .25) and family medicine (OR = .24) specialty, and non-Hispanic black patient (OR = .15) were associated with recommendation. In early catch-up adolescents, concerns that teens will practice riskier behaviors (OR = .57), discomfort discussing STIs with parents (OR = .47), and family medicine specialty (OR = .20) were associated with recommendation. For late catch-up adolescents, family medicine specialty (OR = .13) was associated with recommendation.

CONCLUSIONS

Modifiable factors that impede or influence provider recommendations of HPV vaccines can be addressed through intervention. Overall, findings suggest that efforts should focus on sexuality communication and family medicine specialty.

Quantifying clinical HPV4 dose inefficiencies in a safety net population

PURPOSE

HPV4 is the most expensive vaccine requiring three appropriately timed doses to provide maximal efficacy against two oncogenic HPV types. The primary purpose of this study is to quantify the use of HPV4 vaccine in a safety net health care system in terms of its inefficiencies.

METHODS

A retrospective study of HPV4 dosing from 2006-2009, among females 10-26 years old who sought care in a safety net health care system was conducted to determine dose usage patterns among those at highest risk for cervical cancer. Dose descriptors abstracted from the electronic medical record (EMR) included timing and number in series as well as characteristics of the person to whom and visit at which the dose was given. Dose inefficiencies were separated into "less than three doses" and "mistimed doses" for analysis.

RESULTS

The majority (66%) of HPV4 doses administered were insufficient to induce the maximal immune response necessary for HPV infection prevention. Among on-time doses, 58% were singleton or doublet doses. Mistimed doses accounted for 19% of all doses administered with late intervals being more common than early intervals among those receiving more than one dose (9% vs. 4%, p<0.001). Third doses were mistimed twice as often as second doses (10% vs. 5%, p<0.001). Black women were more likely to have a mistimed second dose and Hispanic women more likely to have a mistimed third dose compared to white women (OR = 1.70 (95% CI: 1.11, 2.61 and 2.44 (1.19, 5.00), respectively). The HPV4-only visit type at which HPV4 was initiated was the most significant predictor of on-time doublet completion.

CONCLUSIONS

In a safety net health care system the large inefficiencies associated with HPV4 vaccination must be addressed in order to maximize our patient's cervical cancer prevention.

Helicobacter pylori CagA: From Pathogenic Mechanisms to Its Use as an Anti-Cancer Vaccine

Helicobacter pylori colonizes the gastric mucosa of more than 50% of the human population, causing chronic inflammation, which however is largely asymptomatic. Nevertheless, H. pylori-infected subjects can develop chronic gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Chronic exposure to the pathogen and its ability to induce epithelial to mesenchymal transition (EMT) through the injection of cytotoxin-associated gene A into gastric epithelial cells may be key triggers of carcinogenesis. By deregulating cell-cell and cell-matrix interactions as well as DNA methylation, histone modifications, expression of micro RNAs, and resistance to apoptosis, EMT can actively contribute to early stages of the cancer formation. Host response to the infection significantly contributes to disease development and the concomitance of particular genotypes of both pathogen and host may turn into the most severe outcomes. T regulatory cells (Treg) have been recently demonstrated to play an important role in H. pylori-related disease development and at the same time the Treg-induced tolerance has been proposed as a possible mechanism that leads to less severe disease. Efficacy of antibiotic therapies of H. pylori infection has significantly dropped. Unfortunately, no vaccine against H. pylori is currently licensed, and protective immunity mechanisms against H. pylori are only partially understood. In spite of promising results obtained in animal models of infection with a number of vaccine candidates, few clinical trials have been conducted so far and with no satisfactory outcomes. However, prophylactic vaccination may be the only means to efficiently prevent H. pylori-associated cancers.

HPV vaccine cross-protection: Highlights on additional clinical benefit

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

Assessment of knowledge about cervical cancer and its prevention among female students aged 17-26 years

OBJECTIVE

To assess knowledge about cervical cancer and its primary and secondary prevention, and identify the sources of information about the disease among female high school and university students in Krakow, Poland.

STUDY DESIGN

This study was based on a questionnaire consisting of 64 questions, divided into six parts: personal data, general knowledge about cervical cancer, estimation of risk factors, knowledge about primary prevention, knowledge about secondary prevention, and information sources. Data were collected from students aged 17-26 years over a 3-month period in 2011 and 2012.

RESULTS

Four hundred women living in Krakow or its vicinity were included in the study. Nearly all respondents (98.5%) had heard of cervical cancer, 89.4% were aware of the risk of death associated with cervical cancer, and 44.8% believed that the disease could affect them in the future. The interviewees considered genetics and family history to be the most important risk factors, followed by infection with human papillomavirus (HPV) and having multiple sex partners. Most (91.5%) respondents had not been vaccinated against HPV, 47.9% did not know where to go to get vaccinated, and 30.1% were unaware of vaccination as a prevention method. Most (91.5%) respondents were aware of cytological screening, and 86.5% thought that they should have it done in the future. Women who had not heard of cytological screening were more likely to be unaware of cervical cancer than women who had heard about cytological screening (odds ratio 0.24, 95% confidence interval 0.11-0.49, p=0.0001). The Internet, television and newspapers were reported to be the main sources of information about the disease.

CONCLUSIONS

General awareness of cervical cancer among young women in Poland is insufficient. HPV infection is not considered to be the major aetiological factor. A relatively high percentage of women in this study had never heard of the HPV vaccine as a way of preventing cervical cancer. Knowledge about cytological screening, however, appears to be much better.

Too fast or not too fast: the FDA's approval of Merck's HPV vaccine Gardasil

There are not many public health issues where views are as extremely polarized as those concerning vaccines, and Merck's HPV vaccine Gardasil is a case in point. Ever since gaining the FDA's approval in 2006, Merck has been heavily criticized for their overly aggressive marketing strategies and lobbying campaigns aimed at promoting Gardasil as a mandatory vaccine. Subsequently, questions have been raised as to whether it was appropriate for vaccine manufacturers to partake in public health policies when their conflicts of interests are so obvious. Some of their advertising campaign slogans, such as "cervical cancer kills x women per year" and "your daughter could become one less life affected by cervical cancer," seemed more designed to promote fear rather than evidence-based decision making about the potential benefits of the vaccine. Although, conflicts of interests do not necessarily mean that the product itself is faulty, marketing claims should be carefully examined against factual science data. Currently Gardasil vaccination is strongly recommended by the U.S. and other health authorities while public concerns about safety and efficacy of the vaccine appear to be increasing. This discrepancy leads to some important questions that need to be resolved. The current review examines key issues of this debate in light of currently available research evidence.