Project description:BackgroundHuman papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. Although the efficacy of the HPV vaccine in preventing the development of cervical pre-malignant lesions has been well demonstrated, the efficacy of the HPV vaccine in preventing HPV infection in the upper respiratory tract has been poorly studied.MethodsIn the context of the IARC cohort study of two versus three doses of HPV vaccine in India, we compared the HPV type prevalence in the oral cavity of women vaccinated with three doses, two doses, or a single dose of quadrivalent HPV vaccine with that of unvaccinated women. A total of 997 oral samples, from 818 vaccinated women and 179 unvaccinated women, were collected at three study sites. All the participants were sexually active at the time of sample collection.ResultsThe age-standardized proportion (ASP) of HPV16/18 infections was 2.0 % (95 % CI, 1.0-3.0 %) in vaccinated women and 4.2 % (95 % CI, 1.2-7.2 %) in unvaccinated women. HPV16 was detected in 3.5 % of single-dose recipients, 1.2 % of two-dose recipients (days 1 and 180), and 1.5 % of three-dose recipients (days 1, 60, and 180), whereas 3.3 % of the unvaccinated women tested positive for HPV16. The same trend was observed for HPV18.DiscussionOur findings agree with those of previous studies on the efficacy of HPV vaccination in reducing oral HPV infections and provide indications that a single vaccine dose may be less efficient than two or three doses in preventing oral HPV infection.
Project description:Indications for human papillomavirus vaccination programs are expanding to boys. However, the rationale behind their inclusion is often not clear. Using a Bayesian synthesis framework and assuming equal vaccine coverage in both sexes, we assessed how the incremental number of cancer cases prevented and life-years gained from boys' vaccination are distributed between women, heterosexual men, and men who have sex with men (MSM). Below 60% coverage, at least 50% of the gains from boys' vaccination was attributable to cervical cancer prevention, whereas at 80% coverage, 50% of the gains was attributable to women, 15% to heterosexual men, and 35% to MSM. Above 90% coverage, 85-100% of the gains from boys' vaccination was attributable to anal and oropharyngeal cancer prevention, mainly in MSM. Sex-neutral vaccination can be advocated on grounds of bolstering herd protection to women and directly protecting men, particularly MSM, with the clinical significance of either argument determined by the coverage.
Project description:(1) Background: To explore the influencing factors of human papillomavirus (HPV) vaccination among mothers and daughters so as to provide evidence and strategies for improving the HPV vaccination rate of 9-18-years-old girls. (2) A questionnaire survey was conducted among the mothers of 9-18-year-old girls from June to August 2022. The participants were divided into the mother and daughter vaccinated group (M1D1), the mother-only vaccinated group (M1D0), and the unvaccinated group (M0D0). Univariate tests, the logistic regression model, and the Health Belief Model (HBM) were employed to explore the influencing factors. (3) Results: A total of 3004 valid questionnaires were collected. According to the regions, Totally 102, 204, and 408 mothers and daughters were selected from the M1D1, M1D0, and M0D0 groups, respectively. The mother having given her daughter sex education (OR = 3.64; 95%CI 1.70, 7.80), the mother's high perception of disease severity (OR = 1.79; 95%CI 1.02, 3.17), and the mother's high level of trust in formal information (OR = 2.18; 95%CI 1.26, 3.78) were all protective factors for both the mother and her daughter's vaccination. The mother's rural residence (OR = 0.51; 95%CI 0.28, 0.92) was a risk factor for vaccination of both mother and daughter. The mother's education of high school or above (OR = 2.12; 95%CI 1.06, 4.22), the mother's high level of HPV and HPV vaccine knowledge (OR = 1.72; 95%CI 1.14, 2.58), and the mother's high level of trust in formal information (OR = 1.72; 95%CI 1.15, 2.57) were protective factors of mother-only vaccination. The older the mother (OR = 0.95; 95%CI 0.91, 0.99) was classed as a risk factor for mother-only vaccination. "Waiting until the daughters are older to receive the 9-valent vaccine" is the main reason why the daughters of M1D0 and M0D0 are not vaccinated". (4) Chinese mothers had a high willingness to vaccinate their daughters with the HPV vaccine. The higher education level of the mother, giving sex education to the daughter, the older ages of mothers and daughters, the mother's high level of HPV and HPV vaccine knowledge, a high level of perception of the disease severity, and a high level of trust in formal information were promoting factors of HPV vaccination for mother and daughter, and rural residence was a risk factor to vaccination. To promote HPV vaccination in girls from 9-18 years old, communities could provide health education to rural mothers with low education levels; the government could advocate for HPV vaccination through issuing policy documents; and doctors and the CDC could popularize the optimal age for HPV vaccination to encourage mothers to vaccinate their daughters at the age of 9-14 years old.
Project description:BackgroundIn Australia in 2017, 89% of 15-year-old females and 86% of 15-year-old males had received at least one dose of the HPV vaccine. However, considerable variation in HPV vaccination initiation (dose one) across schools remains. It is important to understand the school-level characteristics most strongly associated with low initiation and their contribution to the overall between-school variation.MethodsA population-based ecological analysis was conducted using school-level data for 2016 on all adolescent students eligible for HPV vaccination in three Australian jurisdictions. We conducted logistic regression to determine school-level factors associated with lower HPV vaccination initiation (< 75% dose 1 uptake) and estimated the population attributable risk (PAR) and the proportion of schools with the factor (school-level prevalence).ResultsThe factors most strongly associated with lower initiation, and their prevalence were; small schools (OR = 9.3, 95%CI = 6.1-14.1; 33% of schools), special education schools (OR = 5.6,95%CI = 3.7-8.5; 8% of schools), higher Indigenous enrolments (OR = 2.7,95% CI:1.9-3.7; 31% of schools), lower attendance rates (OR = 2.6,95%CI = 1.7-3.7; 35% of schools), remote location (OR = 2.6,95%CI = 1.6-4.3; 6% of schools,) and lower socioeconomic area (OR = 1.8,95% CI = 1.3-2.5; 33% of schools). The highest PARs were small schools (PAR = 79%, 95%CI:76-82), higher Indigenous enrolments (PAR = 38%, 95%CI: 31-44) and lower attendance rate (PAR = 37%, 95%CI: 29-46).ConclusionThis analysis suggests that initiatives to support schools that are smaller, with a higher proportion of Indigenous adolescents and lower attendance rates may contribute most to reducing the variation of HPV vaccination uptake observed at a school-level in these jurisdictions. Estimating population-level coverage at the school-level is useful to guide policy and prioritise resourcing to support school-based vaccination programs.
Project description:BackgroundThe emergence of dengue fever has prompted significant public health responses, highlighting the need for a comprehensive understanding of One Health in addressing vector-borne diseases. China's experience in dengue control and prevention programs offers valuable insights into the successful integration of multidisciplinary strategies.AimsThe review aims to: (1) systematically analyze lessons from China's dengue control and prevention programs, focusing on the integration of these efforts with the One Health approach; (2) underscore the reasons of optimizing the dengue control and prevention program; (3) highlight the alignment of China's dengue control strategies with the One Health framework; (4) contribute to global efforts in combating dengue, providing scientific evidence and strategic recommendations for other regions facing similar challenges.ResultsThrough a comprehensive literature review and expert interviews, this study found China's approach to dengue control and prevention implemented through a hierarchical system led by the government, with collaborative efforts across multiple departments. This multi-sectoral collaboration mechanism enables the technical interventions well executed by health and disease control institutions, optimizing the integration of multiple cost-effeteness approaches, such as case management, early detection and outbreak response, reducing local transmission, and minimizing severe cases and fatalities. It was found that community participation and public health education have played a vital role in raising awareness, promoting personal protective measures, and enhancing the overall effectiveness of control efforts. The implementation of these integrated interventions has resulted in reduced dengue cases and improved capacity of outbreak response. China's dengue control strategies under the One Health framework, with focus on interdisciplinary collaboration, incorporated environmental and ecological interventions, which reduced mosquito breeding sites and improved sanitation. The findings of the review underscore the need for continuous improvement in early warning systems, scientific research, and the adoption of the One Health approach to address emerging challenges posed by climate change and the cross-border spread of infectious diseases.ConclusionChina's dengue control and prevention programs provide a compelling case study for the effective application of the One Health approach. By systematically analyzing the integration of multidisciplinary strategies, this review reveals valuable lessons on optimizing public health responses to vector-borne diseases. The alignment of these strategies with One Health principles not only enhances the effectiveness of dengue control efforts in China but also offers a framework that can be adapted by other regions facing similar challenges. Ultimately, the insights gained from this analysis contribute to the global fight against dengue, emphasizing the need for collaborative and holistic approaches in public health initiatives.
Project description:The significant increase in the incidence rates and ongoing outbreaks of serogroup C meningococcal (MenC) disease, associated with the sequence type-103 complex, motivated the incorporation of the meningococcal C conjugate (MCC) vaccine in the routine immunization program in the State of Bahia, Brazil in early 2010, targeting children younger than 5 years of age. In its capital, Salvador, the program also included a catch-up campaign for individuals 10-24 years of age. We performed an observational, ecological study, analyzing data collected from 2007 to 2015, to compare the impact of these two immunization strategies on meningococcal disease incidence and mortality rates. In Salvador, following the vaccination program, a dramatic early impact on MenC disease and mortality rates could be observed, with significant reductions in incidence rates of MenC disease in all age groups, including individuals that were too old to have been vaccinated, indicating the presence of herd protection. Compared to the pre-vaccine period, a virtual disappearance of MenC disease was observed in 2015. However, in the state of Bahia (excluding the city of Salvador), no herd protection could be observed, with significant impact only among vaccine-eligible children within 5 years of introduction of the MCC vaccination program. These results highlight the importance of catch-up campaigns, including adolescents and young adults, to induce herd protection compared to immunization strategies restricted to infants and young children. This information is crucial for identifying optimal immunization policies and future strategies, focused on adolescents, to optimize the impact of MCC vaccination programs.
Project description:Human papillomavirus (HPV) is the most common sexually transmitted infection, currently affecting close to 80 million Americans. Importantly, HPV infection is recognized as the etiologic factor for numerous cancers, including cervical, vulval, vaginal, penile, anal, and a subset of oropharyngeal cancers. The prevalence of HPV infection and its associated diseases are a significant problem, affecting millions of individuals worldwide. Likewise, the incidence of HPV infection poses a significant burden on individuals and the broader healthcare system. Between 2011 and 2015, there were an estimated 42,700 new cases of HPV-associated cancers each year in the United States alone. Similarly, the global burden of HPV is high, with around 630,000 new cases of HPV-associated cancer occurring each year. In the last decade, a total of three preventive major capsid protein (L1) virus-like particle-based HPV vaccines have been licensed and brought to market as a means to prevent the spread of HPV infection. These prophylactic vaccines have been demonstrated to be safe and efficacious in preventing HPV infection. The most recent iteration of the preventive HPV vaccine, a nanovalent, L1-VLP vaccine, protects against a total of nine HPV types (seven high-risk and two low-risk HPV types), including the high-risk types HPV16 and HPV18, which are responsible for causing the majority of HPV-associated cancers. Although current prophylactic HPV vaccines have demonstrated huge success in preventing infection, existing barriers to vaccine acquisition have limited their widespread use, especially in low- and middle-income countries, where the burden of HPV-associated diseases is highest. Prophylactic vaccines are unable to provide protection to individuals with existing HPV infections or HPV-associated diseases. Instead, therapeutic HPV vaccines capable of generating T cell-mediated immunity against HPV infection and associated diseases are needed to ameliorate the burden of disease in individuals with existing HPV infection. To generate a cell-mediated immune response against HPV, most therapeutic vaccines target HPV oncoproteins E6 and E7. Several types of therapeutic HPV vaccine candidates have been developed including live-vector, protein, peptide, dendritic cell, and DNA-based vaccines. This chapter will review the commercially available prophylactic HPV vaccines and discuss the recent progress in the development of therapeutic HPV vaccines.
Project description:ObjectiveTo synthesise lessons learnt and determinants of success from human papillomavirus (HPV) vaccine demonstration projects and national programmes in low- and middle-income countries (LAMICs).MethodsInterviews were conducted with 56 key informants. A systematic literature review identified 2936 abstracts from five databases; after screening 61 full texts were included. Unpublished literature, including evaluation reports, was solicited from country representatives; 188 documents were received. A data extraction tool and interview topic guide outlining key areas of inquiry were informed by World Health Organization guidelines for new vaccine introduction. Results were synthesised thematically.ResultsData were analysed from 12 national programmes and 66 demonstration projects in 46 countries. Among demonstration projects, 30 were supported by the GARDASIL® Access Program, 20 by Gavi, four by PATH and 12 by other means. School-based vaccine delivery supplemented with health facility-based delivery for out-of-school girls attained high coverage. There were limited data on facility-only strategies and little evaluation of strategies to reach out-of-school girls. Early engagement of teachers as partners in social mobilisation, consent, vaccination day coordination, follow-up of non-completers and adverse events was considered invaluable. Micro-planning using school/ facility registers most effectively enumerated target populations; other estimates proved inaccurate, leading to vaccine under- or over-estimation. Refresher training on adverse events and safe injection procedures was usually necessary.ConclusionConsiderable experience in HPV vaccine delivery in LAMICs is available. Lessons are generally consistent across countries and dissemination of these could improve HPV vaccine introduction.
Project description:BackgroundGardasil®, a quadrivalent vaccine targeting low-risk (6, 11) and high-risk (16, 18) human papillomaviruses (HPV), has been offered to 11-14 year-old schoolgirls in Switzerland since 2008. To evaluate its success and its potential impact on cervical cancer screening, HPV genotypes were examined in 18-year-old girls five years later (sub-study 1) and in outpatients participating to cervical cancer screening before and after vaccine implementation (sub-study 2).MethodsFor sub-study 1, 3726 females aged 18 in 2013 were invited to fill a questionnaire on personal demographics and HPV risk factors and to provide a self-collected cervicovaginal sample for HPV genotyping and Chlamydia trachomatis PCR. Personal data were evaluated by univariable and multivariable statistics. In sub-study 2, the proportion of the vaccine-type HPV among anogenital HPV was examined with archived genotyping data of 8039 outpatients participating to cervical cancer screening from 1999 till 2015. The yearly evolution of this proportion was evaluated by segmented logistic regression.Results690 (18.5%) women participated to sub-study 1 and 327 (8.8%) provided a self-collected sample. Prevalence of Chlamydia trachomatis (4.6%) and demographics confirmed that the subjects were representative of sexually-active Swiss young women. Vaccine (five-year coverage: 77.5%) was preferentially accepted by contraceptive-pill users (P = 0.001) and samples were mainly provided by sexually-active subjects (P < 0.001). The proportion (4%) of the vaccine-type HPV in this population was lower than in sub-study 2 outpatients (n = 849, <26 years old) in the pre-vaccine era (25.7%). The proportion of the high-risk vaccine-type HPV decreased significantly (59%, P = 0.0048) in the outpatients during the post-vaccine era, yet this decrease was restricted to those aged less than 26 years (n = 673, P < 0.0001).ConclusionsThe low proportion of vaccine-type HPV in 18-year-old females and its rapid decrease in young women participating to cervical cancer screening extend the success of HPV vaccination to Switzerland. Our data suggest that cervical cancer screening is now entering a stage of reduced proportion of HPV16 and/or 18 in samples reported positive by cytology. In view of the high likelihood of reduced clinical specificity of cytology, primary screening modalities involving HPV testing and cytology should now be re-evaluated in Switzerland.