Current status of human papillomavirus vaccines

Human Papillomavirus 16 DNA Methylation Patterns and Investigation of Integration Status in Head and Neck Cancer Cases

Persistent high-risk human papillomavirus (HPV) infection is a pivotal factor in the progression of cervical cancer. In recent years, an increasing interest has emerged in comprehending the influence of HPV on head and neck squamous cell carcinoma (HNSCC). Notably, it is well established that HPV-associated HNSCC show cases with distinct molecular and clinical attributes compared to HPV-negative cases. The present study delves into the epigenetic landscape of HPV16, specifically its L1 gene and untranslated region (UTR), through pyrosequencing, while the HPV16 DNA physical status was evaluated using E2/E6 ratio analysis in HPV16-positive HNSCC FFPE biopsies. Our findings reveal substantial methylation across six sites within the HPV16 L1 gene and seven sites in the UTR. Specifically, methylation percentages of two L1 CpG sites (7136, 7145) exhibit significant associations with tumor histological grade (p < 0.01), while proving concurrent methylation across multiple sites. The HPV16 DNA physical status was not correlated with the methylation of viral genome or tumor characteristics. This is the first study that examines epigenetic modifications and the HPV16 DNA physical status in Greek HNSCC patients. Our findings suggest an orchestrated epigenetic modulation among specific sites, impacting viral gene expression and intricate virus-host interactions.

Prognostic significance of HPV16 infection in oral squamous cell carcinoma

Background/Aim: Many studies confirmed strong association between oncogenic genotypes of Human Papillomaviruses (HPVs) and some oropharyngeal and oral squamous cell carcinomas (OSCCs). The aim of this study was to determine the prognostic significance of HPV16 infection in OSCC in population of Montenegro i.e. correlation between HPV16 infection and disease free interval (DFI), disease recurrence and metastasis occurrence. Material and Methods: We examined surgically obtained specimens from 60 patients with OSCC (localized on the lower lip, tongue or/and floor of the mouth) in six years period. Tumor tissue samples were used for histological analysis and HPV16 genome PCR detection (primers for detection of E6 gene). Patients were followed up for the 3 years. Results: HPV16 infection was more commonly detected in females with OSCC (p=0.038), while no correlation between this infection and disease recurrence (p= 0.122) and/or metastasis occurrence (p= 0.934) was found. DFI was not significantly different between patients with or without HPV16 infection (p= 0.427), but DFI was significantly shorter (p= 0.003) in females with oral HPV16 infection compared to male patients with this infection. Conclusions: Counting that HPV16 infection has a negative prognostic significance in OSCC, the HPV immunization program against genital HPV infection, would also have a positive impact on the frequency of HPV-mediated OSCC in Montenegrin population.

Prevalence and clinical implications of the HPV16 infection in oral cancer in Montenegro – Evidence to support the immunization program

Oral squamous cell carcinoma (OSCC) makes 85–95% of all malignances in the oral cavity. Increasing evidence shows that the Human Papillomaviruses (HPVs) are preferentially associated with some oropharyngeal and OSCCs, namely the genotype 16. The aim of the present study was to determine the prevalence and clinical implications of HPV16 infection in oral squamous cell carcinoma in population of Montenegro.

This study included 60 patients with OSCC (localized on the lower lip, tongue or/and floor of the mouth), surgically treated at the Clinical Centre of Montenegro from 2012 to 2018. Surgically obtained formalin-fixed and paraffin-embedded specimens were used for histopathological analysis and HPV16 genome detection using standard Polymerase Chain Reaction (primers for detection of E6 gene). Each individual was further followed up for the period of three years and for different clinico-pathological characteristics, including disease free interval (DFI).

The prevalence of HPV16 infection in OSCCs was 23.3% and the infection was significantly more common in female patients (P = 0.038). No significant correlation was detectable between HPV16 infection and the patients' age (P = 0.302), tumor site (P = 0.125), tumor grade (P = 0.363) and disease stage (P = 0.995). Observing the total sample the DFI was not significantly different for HPV16-positive versus HPV16-negative patients (P = 0.427), but a gender-based difference in DFI was observed, with the significantly shorter DFI (Log Rank test, P = 0.003) in HPV16 positive female patients compared to male patients (P = 0.003).

The results obtained in this study provide scientific evidence for the development of national HPV vaccination program in Montenegro.

Distribution of vaccine-related high-risk human papillomaviruses and their impact on the development of cervical dysplasia in women in Montenegro

Cervical cancer (CC) is the third leading cause of death in women in Montenegro. Human papillomavirus (HPV) is the causative agent of CC however, HPV genotype distribution varies across regions. This study examined the distribution and impact of vaccine-related high-risk (HR)-HPVs on the development of cervical dysplasia in Montenegrin women. A total of 187 women who had a clinical indication for cervical biopsy were enrolled. Based on histopathological findings, women were classified into 2 groups, with and without dysplasia. HR-HPV was detected by real-time PCR. Twelve HR-HPV genotypes were detected in 40.6% of cervical samples. The 7 most prevalent HR-HPVs in order of decreasing frequency were HPV 16 (39.5%), 45 (23.7%), 31 (21.0%), 33 (17.1%), 18 (6.6%), 52 (6.6%), and 58 (6.6%), all of them are targeted by nonavalent vaccine. Vaccine-related HR-HPVs had a higher prevalence (92.1%) than the other HR-HPVs detected in HR-HPV-positive samples. Among HR-HPV-positive women, HPV 16 and 33 were more common in women with dysplasia than in those without dysplasia (HPV 16: 28.9 vs 7.2%; HPV 33: 11.8 vs 3.6%). HPV 16 was the most common HR-HPV genotype in cervical samples, followed by HPV 45, 31, 33, 18, 52, and 58. HPV 16 and 33 were shown to be associated with the development of cervical dysplasia. These results indicate that prophylactic nonavalent vaccine can potentially prevent approximately 90% of HR-HPV infections and 60% of cervical dysplasia cases in Montenegrin women.

Prevalence and genotype distribution of genital human papillomavirus infection in female sex workers in the world: a systematic review and meta-analysis

BACKGROUND

Female sex workers (FSWs) are amongst the most susceptible groups to acquire human papillomavirus (HPV) infection and consequently, to develop cervical intraepithelial neoplasia and cervical cancer. This is the first systematic review and meta-analysis to provide estimates of the pooled prevalence of HPV infection and the distribution of HPV types among FSWs across the world.

METHODS

Five computerized databases were searched for relevant studies published since the inception date of databases to September 2019. The pooled HPV prevalence was calculated by the random effect model described by DerSimonian-Laird. Subgroup analysis was performed to identify the probable sources of heterogeneity. The meta-analysis was performed using the "Metaprop" function in the R package Meta.

RESULTS

Sixty-two studies involving 21,402 FSWs from 33 countries were included in this meta-analysis, and the pooled HPV prevalence was 42.6% (95% confidence interval (CI): 38.5-46.7%). HPV-16 (10.1, 95% CI: 8.2-12.5%), HPV-52 (7.9, 95% CI: 5.9-10.7%), and HPV-53 (6.0, 95% CI: 4.4-8.1%) were the most common high-risk HPV types identified among FSWs. The pooled estimated prevalence of HPV infection among FSWs before and after 2010 were slightly different, 43.6% (95% CI: 36.1-51.4%) and 41.9% (95% CI: 37.2-46.8%), respectively.

CONCLUSION

Due to the high prevalence of HPV infection, particularly with high-risk types, FSWs have a great susceptibility to the development of cervical and vaginal cancers. Furthermore, they can transmit their infection to their clients, which may result in a high prevalence of HPV and the incidence of HPV-associated malignancies among the general population.

Therapeutic Cancer Vaccines-T Cell Responses and Epigenetic Modulation

There is great interest in developing efficient therapeutic cancer vaccines, as this type of therapy allows targeted killing of tumor cells as well as long-lasting immune protection. High levels of tumor-infiltrating CD8⁺ T cells are associated with better prognosis in many cancers, and it is expected that new generation vaccines will induce effective production of these cells. Epigenetic mechanisms can promote changes in host immune responses, as well as mediate immune evasion by cancer cells. Here, we focus on epigenetic modifications involved in both vaccine-adjuvant-generated T cell immunity and cancer immune escape mechanisms. We propose that vaccine-adjuvant systems may be utilized to induce beneficial epigenetic modifications and discuss how epigenetic interventions could improve vaccine-based therapies. Additionally, we speculate on how, given the unique nature of individual epigenetic landscapes, epigenetic mapping of cancer progression and specific subsequent immune responses, could be harnessed to tailor therapeutic vaccines to each patient.

Antigenic Peptide Prediction From E6 and E7 Oncoproteins of HPV Types 16 and 18 for Therapeutic Vaccine Design Using Immunoinformatics and MD Simulation Analysis

Human papillomavirus (HPV) induced cervical cancer is the second most common cause of death, after breast cancer, in females. Three prophylactic vaccines by Merck Sharp & Dohme (MSD) and GlaxoSmithKline (GSK) have been confirmed to prevent high-risk HPV strains but these vaccines have been shown to be effective only in girls who have not been exposed to HPV previously. The constitutively expressed HPV oncoproteins E6 and E7 are usually used as target antigens for HPV therapeutic vaccines. These early (E) proteins are involved, for example, in maintaining the malignant phenotype of the cells. In this study, we predicted antigenic peptides of HPV types 16 and 18, encoded by E6 and E7 genes, using an immunoinformatics approach. To further evaluate the immunogenic potential of the predicted peptides, we studied their ability to bind to class I major histocompatibility complex (MHC-I) molecules in a computational docking study that was supported by molecular dynamics (MD) simulations and estimation of the free energies of binding of the peptides at the MHC-I binding cleft. Some of the predicted peptides exhibited comparable binding free energies and/or pattern of binding to experimentally verified MHC-I-binding epitopes that we used as references in MD simulations. Such peptides with good predicted affinity may serve as candidate epitopes for the development of therapeutic HPV peptide vaccines.

The combinational effect of E6/E7 siRNA and anti-miR-182 on apoptosis induction in HPV16-positive cervical cells

In the present research, we assumed that reducing the amounts of E6 and E7 oncoproteins by a specific siRNA sequence and recovering p53 and RB proteins, along with the recovery of the FOXO1 protein by applying anti-miR-182, would increase apoptosis and reduce proliferation rate in cancer cells. The HPV16-positive CaSki cervical cancer cell line was used. 48 hours after transfection of siRNA for targeting E6 and E7 oncoproteins and anti-miR-182, expression of its cellular targets p53, p21 and FOXO1 was assessed by real-time PCR, western blot analysis and immunocytofluorescence staining. In all treatments, apoptosis rate and viability were evaluated using Annexin-V-FITC apoptosis detection kits and MTT assays, respectively. Among the designed siRNAs, E6-1 and E7-2 proved the most effective in reducing E6 and E7 expressions by increasing the apoptotic rates to 12.4% and 16%, respectively, after 48 hours. Also, using anti-miR-182 increased apoptotic rate to 12.7% 48 hours after transfection of cervical cancer cells. The combinational use of either E6-1 or E7-2 siRNAs with anti-miR-182 resulted in a rise in apoptosis to 19.3% and 26%, respectively, higher than those obtained from the individual application of either without anti-miR-182. The simultaneous use of siRNA E6-1 and siRNA E7-2 with cisplatin increased sensitivity to cisplatin and reduced the viability of the cancer cells as compared to the use of cisplatin alone. The simultaneous use of cisplatin and anti-miR-182 had no considerable effect on viability or apoptosis rate compared to cisplatin alone.

Identification of broadly reactive epitopes targeting major glycoproteins of Herpes simplex virus (HSV) 1 and 2 - An immunoinformatics analysis

Infections due to both HSV-1 and HSV-2 constitute an enormous health burden worldwide. Development of vaccine against herpes infections is a WHO supported public health priority. The viral glycoproteins have always been the major hotspots for vaccine designing. The present study was aimed to identify the conserved T and B cell epitopes in the major glycoproteins of both HSV-1 and HSV-2 via rigorous computational approaches. Identification of promiscuous T cell epitopes is of utmost importance in vaccine designing as such epitopes are capable of binding to several allelic forms of HLA and could generate effective immune response in the host. The criteria designed for identification of T and B cell epitopes was that it should be conserved in both HSV-1 and 2, promiscuous, have high affinity towards HLA alleles, should be located on the surface of glycoproteins and not be present in the glycosylation sites. This study led to the identification of 17 HLA Class II and 26 HLA Class I T cell epitopes, 9 linear and some conformational B cell epitopes. The identified T cell epitopes were further subjected to molecular docking analysis to analyze their binding patterns. Altogether we have identified 4 most promising regions in glycoproteins (2-gB, 1-gD, 1-gH) of HSV-1 and 2 which are promiscuous to HLA Class II alleles and have overlapping HLA Class I and B cell epitopes, which could be very useful in generating both arms of immune response in the host i.e. adaptive as well as humoral immunity. Further the authors propose the cross-validation of the identified epitopes in experimental settings for confirming their immunogenicity to support the present findings.

Identification of T cell and B cell epitopes against Indian HCV-genotype-3a for vaccine development- An in silico analysis

Hepatitis C virus (HCV) infects almost 150 million people and is a leading cause of liver disease worldwide. It has been classified into seven genotypes; the most common genotype affecting Indian population is genotype 3 (60-70%). Currently there is no vaccine for any genotype of HCV. In order to develop peptide based vaccine against HCV, it is important to identify the conservancy in the circulating genotypes, along with the Human Leucocyte Antigen (HLA) alleles in the target population. The present study aims to identify conserved CD4 and CD8 T cells and B cell epitopes against Indian HCV-genotype-3a using an in silico analysis. In the present study, 28 promiscuous CD4 T cell epitopes and some CD8 epitopes were identified. The NS4 region was predicted to be the most antigenic with maximum number of conserved and promiscuous CD4 T cell epitopes and CD8 T cell epitopes having strong and intermediate affinity towards a number of HLA alleles prevalent in Indian population. Additionally, some linear B cell epitopes were also identified, which could generate neutralizing antibodies. In order to ascertain the binding pattern of the identified epitopes with HLA alleles, molecular docking analysis was carried out. The authors suggest further experimental validation to investigate the immunogenicity of the identified epitopes.

Assessing the Importance of Domestic Vaccine Manufacturing Centers: An Overview of Immunization Programs, Vaccine Manufacture, and Distribution

Vaccines have significantly reduced the detrimental effects of numerous human infectious diseases worldwide, helped to reduce drastically child mortality rates and even achieved eradication of major pathogens, such as smallpox. These achievements have been possible due to a dedicated effort for vaccine research and development, as well as an effective transfer of these vaccines to public health care systems globally. Either public or private institutions have committed to developing and manufacturing vaccines for local or international population supply. However, current vaccine manufacturers worldwide might not be able to guarantee sufficient vaccine supplies for all nations when epidemics or pandemics events could take place. Currently, different countries produce their own vaccine supplies under Good Manufacturing Practices, which include the USA, Canada, China, India, some nations in Europe and South America, such as Germany, the Netherlands, Italy, France, Argentina, and Brazil, respectively. Here, we discuss some of the vaccine programs and manufacturing capacities, comparing the current models of vaccine management between industrialized and developing countries. Because local vaccine production undoubtedly provides significant benefits for the respective population, the manufacture capacity of these prophylactic products should be included in every country as a matter of national safety.

Current status and future prospects for human papillomavirus vaccines

Cervical cancer is the fourth most frequent cancer among women worldwide. Human papillomaviruses (HPVs) cause almost all cervical cancers in low-income countries. Three prophylactic HPV virus-like particle-based vaccines have been licensed to date, and they have all shown high efficacy and reliable safety profiles. However, isolated safety issues have resulted in a reluctance to use these vaccinations. In addition, the high prices of the vaccinations have caused the inequitable distribution of the vaccine: the prices are unaffordable for low-income countries. Meanwhile, great effort has been put into the development of therapeutic HPV vaccines, including protein/peptide-, live vector-, DNA- and cell-based vaccines. These new vaccines have considerable therapeutic potential but limited practical use. The development of immune checkpoint inhibitors and personalized immunotherapy remain challenges for future study. In this article, the current status of the licensed vaccines, therapeutic HPV vaccines and biosimilars, and new platforms for HPV vaccines, are reviewed, and safety issues related to the licensed vaccines are discussed. In addition, the prospects for HPV vaccines are considered.

Human papilloma virus in oral cancer

Cervical cancer is the second most prevalent cancer among women, and it arises from cells that originate in the cervix uteri. Among several causes of cervical malignancies, infection with some types of human papilloma virus (HPV) is well known to be the greatest cervical cancer risk factor. Over 150 subtypes of HPV have been identified; more than 40 types of HPVs are typically transmitted through sexual contact and infect the anogenital region and oral cavity. The recently introduced vaccine for HPV infection is effective against certain subtypes of HPV that are associated with cervical cancer, genital warts, and some less common cancers, including oropharyngeal cancer. Two HPV vaccines, quadrivalent and bivalent types that use virus-like particles (VLPs), are currently used in the medical commercial market. While the value of HPV vaccination for oral cancer prevention is still controversial, some evidence supports the possibility that HPV vaccination may be effective in reducing the incidence of oral cancer. This paper reviews HPV-related pathogenesis in cancer, covering HPV structure and classification, trends in worldwide applications of HPV vaccines, effectiveness and complications of HPV vaccination, and the relationship of HPV with oral cancer prevalence.

Immunodominant T-Cell Epitopes in the VP1 Capsid Protein of Rhinovirus Species A and C

Rhinovirus (RV) species A and C are the most frequent cause of respiratory viral illness worldwide, and RV-C has been linked to more severe exacerbations of asthma in young children. Little is known about the immune responses to the different RV species, although studies comparing IgG1 antibody titers found impaired antibody responses to RV-C. Therefore, the aim of this study was to assess whether T-cell immunity to RV-C is similarly impaired. We measured T-cell proliferation to overlapping synthetic peptides covering the entire VP1 capsid protein of an RV-A and RV-C genotype for 20 healthy adult donors. Human leukocyte antigen (HLA) was typed in all the donors in order to investigate possible associations between the HLA type and RV peptide recognition. Total and specific IgG1 antibody titers to the VP1 proteins of both RV-A and RV-C were also measured to examine associations between the antibody and T-cell responses. We identified T-cell epitopes that are specific to and representative of each RV-A and RV-C species. These epitopes stimulated CD4⁺-specific T-cell proliferation, with similar magnitudes of response for both RV species. All the donors, independent of their HLA-DR or -DQ type, were able to recognize the immunodominant RV-A and -C regions of VP1. Furthermore, the presence or absence of specific antibody titers was not related to changes in T-cell recognition. Our results indicate a dissociation between the antibody and T-cell responses to rhinoviruses. The species-representative T-cell epitopes identified in this study are valuable tools for future studies investigating T-cell responses to the different RV species.

IMPORTANCE

Rhinoviruses (RVs) are mostly associated with the common cold and asthma exacerbations, although their contributions to most upper and lower respiratory tract diseases have increasingly been reported. Species C (RV-C) has been associated with more frequent and severe asthma exacerbations in young children and, along with RV-A, is the most clinically relevant species. Little is known about how our immune system responds to rhinoviruses, and there are limited tools to study specific adaptive immunity against each rhinovirus species. In this study, we identified immunodominant T-cell epitopes of the VP1 proteins of RV-A and RV-C, which are representative of each species. The study found that T-cell responses to RV-A and RV-C were of similar magnitudes, in contrast with previous findings showing RV-C-specific antibody responses were low. These findings will provide the basis for future studies on the immune response to rhinoviruses and can help elucidate the mechanisms of severity of rhinovirus-induced infections.

HPV Vaccination: Attitude and Knowledge among German Gynecologists

Purpose: In order to achieve a higher vaccination rate, education on HPV as well as options for prophylaxis performed by doctors is of great importance. One opportunity to increase the protection against HPV would be vaccinating boys. This study evaluated attitude and knowledge among German gynecologists regarding HPV vaccination, especially in boys. Material and Methods: A questionnaire with 42 questions about demographics, attitude and knowledge about HPV and HPV vaccination was sent to members of the German Society for Gynecology and Obstetrics (DGGG). Results: 998 out of 6567 addressed gynecologists participated. Knowledge about HPV, associated diseases and possible HPV vaccines was high among participants. The attitude towards vaccination in boys as well as girls was positive. Only 8.2 % refused to vaccinate their sons whereas 2.2 % refused to do this for their daughters. However, only few gynecologists vaccinated their daughters and sons against HPV. Main reason for girls was an age outside of vaccination guidelines; for boys it was the lack of cost coverage. Conclusion: The willingness of gynecologists to perform HPV vaccination in boys is as high as for girls. However, sons of gynecologists are only rarely vaccinated against HPV. Main reason is the lack of cost coverage. Vaccinating boys could decrease the disease burden in males, as well as protect women by interrupting ways of transmission. Since the main argument against vaccination of boys is only of financial nature, the necessity of a vaccination recommendation for boys needs to be re-evaluated taking into account the cost-reduced 2-dose vaccination scheme.

Roles of Human Papillomaviruses and p16 in Oral Cancer

Head and neck cancer, including oral cancer, is the sixth most common cancer in humans worldwide. More than 90% of oral cancers are of squamous cell carcinoma type. Recent studies have shown a strong relationship between human papillomavirus (HPV) infection and head and neck cancer, especially oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC). Moreover, the incidence of HPV-related OSCC appears to be on the rise while HPV-unrelated OSCC tends to have stabilized in the past decades. p16, a tumor suppressor gene, normally functions as a regulator of the cell cycle. Upon infection with high-risk types of HPV (HR-HPV), particularly types 16, 18, 31, 33, 34, 35, 39, 51, 52, 56, 58, 59, 66, 68, and 70, the expression of p16 is aberrantly overexpressed. Therefore, the expression of p16 is widely used as a surrogate marker for HPV infection in head and neck cancer.

Challenges and opportunities of using liquid chromatography and mass spectrometry methods to develop complex vaccine antigens as pharmaceutical dosage forms

Liquid chromatographic methods, combined with mass spectrometry, offer exciting and important opportunities to better characterize complex vaccine antigens including recombinant proteins, virus-like particles, inactivated viruses, polysaccharides, and protein-polysaccharide conjugates. The current abilities and limitations of these physicochemical methods to complement traditional in vitro and in vivo vaccine potency assays are explored in this review through the use of illustrative case studies. Various applications of these state-of-the art techniques are illustrated that include the analysis of influenza vaccines (inactivated whole virus and recombinant hemagglutinin), virus-like particle vaccines (human papillomavirus and hepatitis B), and polysaccharide linked to protein carrier vaccines (pneumococcal). Examples of utilizing these analytical methods to characterize vaccine antigens in the presence of adjuvants, which are often included to boost immune responses as part of the final vaccine dosage form, are also presented. Some of the challenges of using chromatographic and LC-MS as physicochemical assays to routinely test complex vaccine antigens are also discussed.

High-throughput characterization of virus-like particles by interlaced size-exclusion chromatography

The development and manufacturing of safe and effective vaccines relies essentially on the availability of robust and precise analytical techniques. Virus-like particles (VLPs) have emerged as an important and valuable class of vaccines for the containment of infectious diseases. VLPs are produced by recombinant protein expression followed by purification procedures to minimize the levels of process- and product-related impurities. The control of these impurities is necessary during process development and manufacturing. Especially monitoring of the VLP size distribution is important for the characterization of the final vaccine product. Currently used methods require long analysis times and tailor-made assays. In this work, we present a size-exclusion ultra-high performance liquid chromatography (SE-UHPLC) method to characterize VLPs and quantify aggregates within 3.1min per sample applying interlaced injections. Four analytical SEC columns were evaluated for the analysis of human B19 parvo-VLPs and murine polyoma-VLPs. The optimized method was successfully used for the characterization of five recombinant protein-based VLPs including human papillomavirus (HPV) VLPs, human enterovirus 71 (EV71) VLPs, and chimeric hepatitis B core antigen (HBcAg) VLPs pointing out the generic applicability of the assay. Measurements were supported by transmission electron microscopy and dynamic light scattering. It was demonstrated that the iSE-UHPLC method provides a rapid, precise and robust tool for the characterization of VLPs. Two case studies on purification tools for VLP aggregates and storage conditions of HPV VLPs highlight the relevance of the analytical method for high-throughput process development and process monitoring of virus-like particles.

E5 and E6/E7 of high-risk HPVs cooperate to enhance cancer progression through EMT initiation

It is estimated that 10-20% of human carcinogenesis is linked to virus infection including papillomaviruses (HPVs). Moreover, since metastatic cancer disease is a major cause of morbidity and mortality in cancer patients, the role of onco-viruses in cancer progression to a metastatic form is of particular interest. Recent studies reported that E5 and E6/E7 onco-proteins of high-risk HPVs could enhance cancer progression via the initiation of the epithelial-mesenchymal transition (EMT) event. Herein, we discuss the association between E5 as well as E6/E7 of high-risk HPV and cancer progression.

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

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

Genetics and vaccines in the era of personalized medicine

Vaccines represent the most successful and sustainable tactic to prevent and counteract infection. A vaccine generally improves immunity to a particular disease upon administration by inducing specific protective and efficient immune responses in all of the receiving population. The main known factors influencing the observed heterogeneity for immune re-sponses induced by vaccines are gender, age, co-morbidity, immune system, and genetic background. This review is mainly focused on the genetic status effect to vaccine immune responses and how this could contribute to the development of novel vaccine candidates that could be better directed and predicted relative to the genetic history of an individual and/or population. The text offers a brief history of vaccinology as a field, a description of the genetic status of the most relevant and studied genes and their functionality and correlation with exposure to specific vaccines; followed by an inside look into autoimmunity as a concern when designing vaccines as well as perspectives and conclusions looking towards an era of personalized and predictive vaccinology instead of a one size fits all approach.

Sub-acute toxicity study in female ICR mice following repetitive intramuscular injection of cervical cancer vaccines

OBJECTIVES

The sub-acute toxic effects following repetitive intramuscular injection of two cervical cancer vaccines newly developed against human papillomaviruse (HPV)16/58/18 and HPV16 were investigated in female ICR (CrljOri: CD1) mice, and the no-observedadverse- effect-level (NOAEL) of the cervical cancer vaccines was estimated.

METHODS

Female ICR mice (n=15 in each group) were exposed to a 1:1 mixture of two cervical cancer vaccines by repetitive intramuscular injection (once a week, 5 times) for 5 weeks. Mortality, body weight, organ weight, hematological/biochemical parameters, and histopathological effects were examined at different concentrations (0, 1×10(8), 5×10(8), and 2.5×10(9) copies/animal) of the cervical cancer vaccines.

RESULTS

The cervical cancer vaccines did not show toxic responses for body weight, absolute/ relative organ weight, hematological/biochemical parameters, or histopathological parameters.

CONCLUSIONS

Female ICR mice exposed to vaccines for cervical cancer did not show any toxic response. We suggest that a NOAEL of the vaccine following repetitive intramuscular injection for 5 weeks is >2.5×10(9) copies/animal.