Human papillomavirus (HPV) vaccination: from clinical studies to immunization programs

Evaluation of female university students' knowledge, attitudes, and practices toward human papillomavirus infection and vaccination. Multicenter cross-sectional study

INTRODUCTION

Having good knowledge and a favorable attitude toward human papillomavirus (HPV) and HPV vaccinations is the cornerstone for increasing the use of HPV vaccinations and preventing cervical cancer. The objective of this study was to evaluate the level of knowledge, attitudes, and practices regarding HPV and HPV vaccinations, as well as to identify associated factors among female undergraduate health science students at both the University of Gondar (UoG) and Bahir Dar University (BDU), Amhara, Ethiopia.

METHODS

Institutional-based multicenter descriptive cross-sectional study was conducted from June 1, 2023, to July 30, 2023. A multistage sampling technique was used to select 633 female undergraduate health science students, and data were collected using a structured, self-administered questionnaire. The data were coded, entered in Epi-data, and exported to SPSS for analysis. Variables with a P-value < 0.25 in the bivariate analysis were inserted in a multivariate logistic regression model, and those with a P-value of < 0.05 in the multivariate binary logistic regression were considered statistically significant factors for knowledge, attitude, and practice regarding HPV and vaccine against it.

RESULTS

The study included 600 participants with a mean age of 20.8 ± 0.75 years. Using Bloom's cutoff points for the KAP study, among the participants, 436 (72.7%) had good knowledge about HPV, whereas 315 (52.5%) had good knowledge about HPV vaccinations. More than half of the participants, 359 (59.8%) heard about HPV vaccinations in Ethiopia. More than half of the participants, 342 (57%) had favorable attitudes toward HPV vaccinations. Only 261 (43.5%) participants believed the HPV vaccine was safe and effective. All participants had never been tested for HPV, and 471 (78.5%) refused to have their samples for regular HPV testing. The factors like ages between 21 and 23 years (AOR, 2.12, 95% CI: 1.22-3.09) and favorable attitudes toward HPV vaccinations (AOR: 1.88; 95%, CI: 1.15-3.41) were associated with the participant's knowledge about HPV vaccinations. Having good knowledge about the virus (AOR: 1.92; 95%, CI: 1.11-5.88) and its vaccine (AOR:1.60; 95%CI: 1.07-2.47) were factors associated with the attitude of the participants about HPV vaccinations. Additionally, HPV vaccination practice was significantly associated with the attitude of the participants toward HPV vaccinations (AOR: 1.85; 95%CI: 1.15-3.45), knowledge about HPV (AOR: 1.18; 95%CI: 0.55-5.50), and HPV vaccinations (AOR: 1.85; 95%CI: 1.08-2.44).

CONCLUSION

This study revealed that half of the students had good knowledge and a favorable attitude toward HPV vaccinations, but there was poor HPV vaccination practice. There is still a need for continued health education, training, and counseling services for students to strengthen HPV vaccination practices, improve students' attitudes and knowledge about the benefits of vaccination, and improve counseling abilities against HPV-induced cancer.

Clinical applications and utility of ctDNA in cervical cancer and its precursor lesions: from screening to predictive biomarker

Cervical cancer is a leading cause of gynecological cancer death in the world. Human papillomavirus (HPV) is the most causative factor of cervical cancer. In addition, many genetic factors are involved in cervical cancer development. Most studies focus on cervical samples to do research work about cervical cancer and precancerous lesions, but no sensitive or specific biomarkers were found. High-throughput genomic technologies are able to capture information from tumors and precancerous lesions in blood, thus providing a new way for the early diagnosis of cervical precancer and cervical cancer. Blood is an ideal specimen for detecting cancer biomarkers because it contains a lot of information, such as circulating tumor cells and circulating tumor DNA (ctDNA). This article reviews the clinical use and challenges of blood ctDNA testing in patients with cervical precancer and cervical cancer.

An Update on Human Papilloma Virus Vaccines: History, Types, Protection, and Efficacy

Human papillomavirus (HPV) is the most common sexually transmitted agent worldwide. Early prevention with HPV vaccination is a safe and effective method against this disease. HPV vaccines provided more protection against several oncogenic HPV strains. Three prophylactic HPV vaccines have been approved to target high-risk HPV types and protect against HPV-related disorders. These existing vaccines are based on the recombinant DNA technology and purified L1 protein that is assembled to form HPV empty shells. The prophylactic vaccines are highly immunogenic and can induce production of specific neutralizing antibodies. However, therapeutic vaccines are different from these prophylactic vaccines. They induced cell-mediated immunity against transformed cells, instead of neutralizing antibodies. The second generation of prophylactic HPV vaccines, made from alternative viral components using cost-effective production strategies, is undergoing clinical evaluation. The purpose of this review is to provide a complete and up-to-date review of the types of HPV vaccines and the efficiency of each of them for readers.

High-risk human papillomavirus infection among women living with HIV in Latin America and the Caribbean: A systematic review and meta-analysis

We carried out a systematic review to summarize available data regarding prevalence of high-risk human papillomavirus (HR-HPV) among women living with HIV (WLHIV) in Latin America and the Caribbean (LAC). A literature search in PubMed and LILACS was conducted and supplemented with cross-referencing and grey literature. The primary outcome was prevalence of HR-HPV by age as a major determinant of HPV infection. Pooled prevalence and weighted averages were obtained. A random effects meta-analysis conducted for HPV- and HIV-associated factors. In total, 6157 women from 19 cross-sectional studies were included. Weighted prevalence of HR-HPV in WLHIV was 51.0% (95% CI 42.8-59.1, I2 = 97.4%) with a bimodal trend by age. No association between antiretroviral therapy and HR-HPV prevalence was observed, but low CD4 cell count was associated (PR 1.64, 95% CI 1.07-2.52). Although not significant, a higher HR-HPV prevalence was observed with Hybrid Capture 2 versus PCR. The high prevalence of HR-HPV among WLHIV in LAC underlines the need for improved cervical cancer prevention and early detection in this vulnerable population. Moreover, the high prevalence across age groups, and particularly in young women, deserves careful consideration for defining target populations of HPV-based screening and HPV immunization programs.

Mannose-Modified Liposome Co-Delivery of Human Papillomavirus Type 16 E7 Peptide and CpG Oligodeoxynucleotide Adjuvant Enhances Antitumor Activity Against Established Large TC-1 Grafted Tumors in Mice

Background

Previously, we demonstrated the therapeutic efficacy of a human papillomavirus (HPV) vaccine, including HPV16 E7 peptide and CpG oligodeoxynucleotides (CpG ODN), against small TC-1 grafted tumors. Here, we developed an HPV16 E7 peptide and CpG ODN vaccine delivered using liposomes modified with DC-targeting mannose, Lip E7/CpG, and determined its anti-tumor effects and influence on systemic immune responses and the tumor microenvironment (TME) in a mouse large TC-1 grafted tumor model.

Methods

L-alpha-phosphatidyl choline (SPC), cholesterol (CHOL), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000)] (DSPE-PEG-2000), 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) and Mannose-PEG-DSPE, loaded with HPV16 E7 peptide and CpG ODN, were used to construct the Lip E7/CpG vaccine. The anti-tumor effects and potential mechanism of Lip E7/CpG were assessed by assays of tumor growth inhibition, immune cells, in vivo cytotoxic T lymphocyte (CTL) responses and cytokines, chemokines, CD31, Ki67 and p53 expression in the TME. In addition, toxicity of Lip E7/CpG to major organs was evaluated.

Results

Lip E7/CpG had a diameter of 122.21±8.37 nm and remained stable at 4°C for 7 days. Co-delivery of HPV16 E7 peptide and CpG ODN by liposomes exerted potent anti-tumor effects in large (tumor volume ≥200mm³) TC-1 grafted tumor-bearing mice with inhibition rates of 80% and 78% relative to the control and Free E7/CpG groups, respectively. Vaccination significantly increased numbers of CD4+ and CD8+ T cells, and IFN-γ-producing cells in spleens and tumors and enhanced HPV-specific CTL responses, while reducing numbers of inhibitory cells including myeloid-derived suppressor cells and macrophages. Expression of cytokines and chemokines was altered and formation of tumor blood vessels was reduced in the Lip E7/CpG group, indicating possible modulation of the immunosuppressive TME to promote anti-tumor responses. Lip E7/CpG did not cause morphological changes in major organs.

Conclusion

Lip E7/CpG induced anti-tumor effects by enhancing cellular immunity and improving tumor-associated immunosuppression. Mannose-modified liposomes are the promising vaccine delivery strategy for cancer immunotherapy.

Universal Human Papillomavirus Vaccination and its Impact on the Southern Italian Region

HPV is still the most common sexually transmitted infection, leading to the onset of many disorders while causing an increase in direct and indirect health costs. High Risk (HR) HPV is the primary cause of invasive cervical cancer and contributes significantly to the development of anogenital and oropharyngeal cancers. The introduction of universal HPV vaccination has led to a significant reduction in vaccine-targeted HPV infections, cross-protective genotypes, precancerous lesions and anogenital warts. Despite the several limitations of HPV vaccination programs, including vaccine type specificity, different schedules, target age-groups and poor communication, the impact has become increasingly evident, especially in countries with high vaccine uptake. We carried out a review of the most recent literature to evaluate the effects of HPV vaccination on vaccinetargeted HPV genotypes and to assess the level of cross-protection provided against non-vaccine HPV types. Subsequently, to assess the rates of HPV infection in a southeast Italian region, we performed an epidemiological investigation on the impact of vaccination on genotypes and on the prevalence and distribution of HPV infection during the twelve-year period 2006-2017 in the Local Health Unit (LHU) of Lecce. The vaccination coverage of about 70% among girls in the LHU led to an initial reduction in vaccine-targeted HPV types and cross-protective genotypes. However, the results on this population should be interpreted cautiously because the period since the start of vaccination is too short and the coverage rate is not yet optimal to evaluate the efficacy of vaccination in lowering the prevalence of non-vaccine HR HPV types in the vaccinated cohort and in older subjects. Nevertheless, it is expected that direct effects will increase further and that herd immunity will begin to emerge as vaccination coverage increases.

Time trends and age-period-cohort analysis of cervical cancer mortality rate in Brazil

BACKGROUND

Cervical cancer (CC) is a common preventable and curable disease that may lead to death. Our aim was to describe the patterns of time trends in CC mortality rates among women in Brazil from 1980 to 2017, and identify the influence of age, period and birth cohort (APC) stratified by region (North NR, Northeast NER, Southeast SER, South SR, Center-Western region CWR).

METHODS

We performed a time-series analysis using secondary data bases. Crude (MR) and WHO age-standardized CC mortality rates (aMR) were estimated per 100,000 women. We evaluated time trends using permutation joinpoint regression models (JP) and APC models to estimate the effect of APC on MR.

RESULTS

The JP analysis showed a temporal decrease in all regions, except the NR, which had an annual percentage increase of 0.44 (95%CI 0.2 - 0.7). MR in the NR was 2 to 4 times higher than in the other regions. We observed steady increases in MR with age in the NR and NER. A plateau after age 40 was observed in SER, SR, and CWR. The NR and NER MR ratio stabilized around the year 2000. Birth cohort effect showed decreasing MR ratio from 1900 to 1970 for all regions, except the NR, which showed increasing MR rate from older to more recent cohorts.

CONCLUSION

We showed relevant differences in cervical MR by region, which may reflect inequality in access to primary and secondary prevention as well as treatment, particularly in the NR.

Role of Epstein-Barr Virus and Human Papillomavirus Coinfection in Cervical Cancer: Epidemiology, Mechanisms and Perspectives

High-risk human papillomavirus (HR-HPV) is etiologically associated with the development and progression of cervical cancer, although other factors are involved. Epstein-Barr virus (EBV) detection in premalignant and malignant tissues from uterine cervix has been widely reported; however, its contribution to cervical cancer development is still unclear. Here, a comprehensive analysis regarding EBV presence and its potential role in cervical cancer, the frequency of EBV/HR-HPV coinfection in uterine cervix and EBV infection in tissue-infiltrating lymphocytes were revised. Overall, reports suggest a potential link of EBV to the development of cervical carcinomas in two possible pathways: (1) Infecting epithelial cells, thus synergizing with HR-HPV (direct pathway), and/or (2) infecting tissue-infiltrating lymphocytes that could generate local immunosuppression (indirect pathway). In situ hybridization (ISH) and/or immunohistochemical methods are mandatory for discriminating the cell type infected by EBV. However, further studies are needed for a better understanding of the EBV/HR-HPV coinfection role in cervical carcinogenesis.

Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines, which were introduced in many countries in the past decade, have shown promising results in decreasing HPV infection and related diseases, such as warts and precancerous lesions. In this review, we present the updated information about current HPV vaccines, focusing on vaccine coverage and efficacy. In addition, pan-gender vaccination and current clinical trials are also discussed. Currently, more efforts should be put into increasing the vaccine’s coverage, especially in low- and middle-income countries. Provision of education on HPV and vaccination is one of the most important methods to achieve this. Vaccines that target HPV types not included in current vaccines are the next stage in vaccine development. In the future, all HPV-related cancers, such as head and neck cancer, and anal cancer, should be tracked and evaluated, especially in countries that have introduced pan-gender vaccination programs. Therapeutic vaccines, in combination with other cancer treatments, should continue to be investigated.

Human Papillomavirus (HPV) Vaccine Knowledge, Awareness and Acceptance among Dental Students and Post-Graduate Dental Residents

Introduction: The recent development of a vaccine that is highly effective against the human papillomavirus (HPV) has been met with widespread clinical and public health professional acceptance. However, social and societal barriers to vaccination may hamper public health efforts to prevent HPV-mediated diseases. Although a few studies have evaluated knowledge or awareness of HPV vaccination among dentists or dental educators, few studies have evaluated the acceptance, knowledge and awareness of HPV vaccination among dental students and post-graduate dental residents. The primary goal of this study is to evaluate survey responses regarding acceptance, knowledge and awareness of HPV vaccination among dental students and post-graduate dental residents. Methods: This study was a retrospective analysis of a previously administered and collected questionnaire. The original protocol was reviewed by the UNLV Biomedical Institutional Research Board (IRB) and was deemed excluded from IRB review (OPRS#0811-2911). Results: Two hundred and ninety-three (N = 293) dental student and forty-one (N = 41) post-graduate dental resident questionnaires were available for a total sample size of N = 334. In brief, although the majority of dental students and residents agreed that vaccines are safe and effective, less than half of dental students (37.5%) or dental residents (48.7%) had discussed the HPV vaccine with a physician or had received the vaccine themselves. In addition, a significant percentage of dental students and residents felt they did not have enough information regarding the HPV vaccine (25.6% and 26.8%, respectively) or had significant concerns about the side effects (17.1%). Conclusions: The data suggest more specific information in dental school microbiology and immunology courses might be needed to increase awareness and knowledge of the safety and effectiveness of vaccines, including the HPV vaccine. This enhanced education might also serve as a curricular focal point to answer questions regarding vaccine-related side effects and provide a mechanism for answering important questions regarding this vaccine.