Human Papillomavirus Research Articles

Human papillomavirus and male infertility correlation analysis following World Health Organization 2021 guidelines

Male infertility is a complex issue influenced by multiple environmental and pathological factors. In this context, the impact of Human papillomavirus (HPV) infection on male fertility remains controversial. The introduction of new WHO 2021 evaluation criteria, included in the 6th ed. of Laboratory Manual for the examination and processing of human semen, i.e. DNA fragmentation index (DFI), slow and rapid progressive motility, could provide additional information about this correlation. 121 semen samples of male partners of HPV-positive women attending In Vitro Fertilization (IVF) were evaluated following WHO 2021 and HPV-DNA test. Comparing HPV-negative and positive samples for rapid and slow progressive motility showed significantly different results (p = 0.0018, p = 0.0004), contrary to what was observed for total progressive motility. Regarding sperm DFI, only high-risk HPV infections affected DNA integrity. In addition, the correlation between the different semen parameters revealed a significant correlation between midpiece morphological defects and rapid progressive motility in the HPV-positive group (rho = 0.43, p = 0.0006). In conclusion, WHO 2021 provides additional information regarding HPV’s impact on seminal parameters. The correlation between HPV positivity, midpiece defects and a higher rapid progressive motility opens new research perspectives that may help unravel the issues surrounding the role of HPV in compromising sperm quality.

Aurora B inhibitors promote RB hypophosphorylation and senescence independent of p53-dependent CDK2/4 inhibition

Aurora B kinase (AURKB) inhibitors have been trialled in a range of different tumour types but are not approved for any indication. Expression of the human papilloma virus (HPV) oncogenes and loss of retinoblastoma (RB) protein function has been reported to increase sensitivity to AURKB inhibitors but the mechanism of their contribution to sensitivity is poorly understood. Two commonly reported outcomes of AURKB inhibition are polyploidy and senescence, although their relationship is unclear. Here we have investigated the major cellular targets of the HPV E6 and E7, p53 and RB, to determine their contribution to AURKB inhibitor induced polyploidy and senescence. We demonstrate that polyploidy is a universal feature of AURKB inhibitor treatment in all cell types including normal primary cells, but the subsequent outcomes are controlled by RB and p53. We demonstrate that p53 by regulating p21 expression is required for an initial cell cycle arrest by inhibiting both CDK2 and CDK4 activity, but this arrest is only triggered after cells have undergone two failed mitosis and cytokinesis. However, cells can enter senescence in the absence of p53. RB is essential for AURKB inhibitor-induced senescence. AURKB inhibitor induces rapid hypophosphorylation of RB independent of inhibition of CDK2 or CDK4 kinases and p53. This work demonstrates that p53 activation determines the timing of senescence onset, but RB is indispensable for senescence.

HPV infection and endometrial polyps: insights from a case-control study

BackgroundEndometrial polyps are common benign lesions characterized by localized overgrowths of endometrial tissue within the uterine cavity. The etiology and pathogenesis of these polyps remain unclear. Human papillomavirus (HPV) infection, known for its association with various genital tract conditions, has been investigated concerning endometrial polyps, although research in this area is limited.MethodsA case-control study involving 62 premenopausal women was conducted, with endometrial polyp cases and control groups matched for age and BMI. Biopsy samples were collected for HPV testing using polymerase chain reaction (PCR). Clinical and demographic data were collected and analyzed for associations between HPV presence and endometrial polyps.ResultsResults showed a higher prevalence of HPV (all types) in cases (4, 12.9%) compared to controls (1, 3.2%), with low-risk HPV being the most prevalent genotype detected and HPV 16 tested positive in one case diagnosed with polyp. While no significant association was found between HPV infection and the presence of endometrial polyps, the study suggests a potential role for HPV in their development. Interestingly, HPV presence in endometrial polyps was unrelated to histopathological features, patients’ age, or BMI.ConclusionThis study provides insights into the potential involvement of HPV infection in the development of endometrial polyps. Despite no significant association found, the prevalence of HPV in these polyps suggests a possible contributory role. Further research with larger sample sizes and more robust methodologies is warranted to clarify this association and its clinical implications.

Prevalence, Characteristics, and Distribution of Human Papillomavirus According to Age and HIV Status in Women of Eastern Cape Province, South Africa

Human papillomavirus (HPV) is a sexually transmitted infection associated with the development of cervical cancer. This study investigated cervical HPV prevalence, characteristics, and distribution according to age and human immunodeficiency virus (HIV) status among women attending a public community health facility in the Eastern Cape Province of South Africa. A total of 325 participants (aged 18 to 60) visiting a community health facility for any reason were recruited. Cervical HPV infection was detected using the Seegene Anyplex™ II HPV28 assay (Seegene Inc., Seoul, South Korea). Overall HPV prevalence was 65.2% (95% CI: 59.9–70.2%), with the highest prevalence of 80.9% (95% CI: 67.2–89.8%) observed in the 18–25-year-old age group and the lowest prevalence of 46.3% (95% CI: 35.8–57.1%) in the 46–60-year-old age group. HR-HPV infection was found to decrease with increasing age (p < 0.001) in the overall population and according to HIV status. In contrast, LR-HPV infection was found to significantly decrease with age among HIV-negative women (p = 0.001) but not for the overall population and HIV-positive women. A proportion of 12.9% were infected with one or more HPV types covered by the Cervarix® HPV vaccine (HPV-16 and/or -18), 18.8% (by those covered by Gardasil®4 (HPV-6, -11, -16 and/or -18), and 42.2% by those covered by Gardasil®9 (HPV-6, -11, -16, -18, -31, -33, -45, -52 and/or -58). The alpha-9 HPV species was the most dominant species (40.6%), followed by the alpha-7 species (29.8%). High overall HPV, HR-HPV, and alpha-9 species prevalence were observed among the women attending the public health facility. These findings contribute to the limited HPV distribution data among the Eastern Cape women, which could be used to improve HPV-related policy and assess the effectiveness of the HPV vaccination.

HPV and p53 status as precision determinants of head and neck cancer response to DNA-PKcs inhibition in combination with irradiation

Abstract Major risk factors of head and neck squamous cell carcinoma (HNSCC) are tobacco use and human papillomavirus (HPV). HPV E6 oncoprotein leads to p53 degradation, whereas HPV-negative cancers are frequently associated with TP53 mutations. Peposertib is a potent and selective, orally administered small-molecule inhibitor of the catalytic subunit of the DNA-dependent kinase (DNA-PKcs), a key regulator of non-homologous end joining (NHEJ). NHEJ inhibition along with irradiation (IR)-induced DNA double-strand breaks has the potential to increase antitumor treatment efficacy. Here, we investigated the responses of a panel of HNSCC models with distinct HPV and p53 status to treatments with IR, DNA-PKcs inhibition, and their combination in-vitro and in-vivo. IR-induced DNA damage combined with peposertib administration shortly before IR results in decreased cell viability and proliferation and causes DNA repair delay in all studied HNSCC cell lines. However, our data confirm that the actual cell fate upon this treatment is determined by cellular p53 and/or HPV status. Cells lacking functional p53 due to its degradation by HPV or due to a loss-of-function mutation are arrested in the G2/M phase of the cell cycle and eliminated by apoptosis whereas p53-proficient HNSCC cell lines preferentially undergo senescence. This is also recapitulated in-vivo, where HPV+ UD-SCC-2 xenografts display stronger and more durable responses to the combined treatment as compared to p53 wild-type UM-SCC-74A tumors. In conclusion, DNA-PKcs inhibitor peposertib should be further studied as a potential radiosensitizer for HNSCCs, taking into consideration the genetic background and the HPV status of a particular tumor.

Cervical precancer screening using self-sampling, HPV DNA testing, and mobile colposcopy in a hard-to-reach community in Ghana: a pilot study

BackgroundThe World Health Organization has set ambitious goals to eliminate cervical cancer, necessitating evidence on increasing coverage and access to screening and treatment in high-burden areas. We implemented a pilot program to assess the feasibility of obtaining self-collected specimens for high-risk human papillomavirus (hr-HPV) testing in Nzulezo stilt village, a hard-to-reach community in Ghana, and inviting only hr-HPV-positive women to a central location for colposcopy and possible treatment. Subsequently, this study aimed to investigate the prevalence of hr-HPV infection and cervical lesions among the women and to explore factors potentially associated with hr-HPV infection among them.MethodsThis pilot community-based cross-sectional study utilized data from screening sessions held from 2 to 20 November 2021 with specimens collected by participants using Evalyn brushes. HPV DNA testing was performed using the Sansure MA-6000 platform, while visual inspection utilized the Enhanced Visual Assessment (EVA) mobile colposcope. Univariate and multivariable nominal logistic regression was employed to explore factors associated with hr-HPV positivity.ResultsAmong 100 women screened (mean age, 43.6 ± 14.5 years), the overall hr-HPV prevalence rate was 39.0% (95% CI, 29.4–49.3). The prevalence rates of hr-HPV genotypes were stratified as follows: HPV16–8.0% (95% CI, 3.5–15.2), HPV18–5.0% (95% CI, 1.6–11.2), and other genotype(s) – 31.0% (95% CI, 22.1–41.0). Single-genotype infections with HPV16 and HPV18 were found in 4.0% (95% CI, 1.1–9.9) and 3.0% (95% CI, 0.6–8.5) of women, respectively. Mixed infections were observed in 1.0% (95% CI, 0.0–5.4) for HPV16 + 18, 3.0% (95% CI, 0.6–8.5) for HPV16 + other type(s), and 1.0% (95% CI, 0.0–5.4) for HPV18 + other type(s). The prevalence of cervical lesions among hr-HPV-positive women screened via colposcopy was 11.4% (95% CI, 3.2–26.7). In the multivariable model, reliance on other sources for medical bill payment was associated with hr-HPV infection (aOR, 0.20; 95% CI, 0.04–0.93), whereas age was not (aOR, 1.02; 95% CI, 0.99–1.05).ConclusionsA high hr-HPV infection prevalence was recorded among the women. Utilizing technologies such as self-sampling, HPV DNA testing, and mobile colposcopy enables screening and treatment in remote and hard-to-reach communities where access to cervical cancer screening and treatment would otherwise be limited. Further research is warranted to assess the value and scalability of this approach in similar remote areas and its potential implementation in future programs.

Acceptance of Human Papillomavirus (HPV) vaccine among the parents of eligible daughters (9–15 years) in Bangladesh: A nationwide study using Health Belief Model

Background To align with the 2030 vision of the World Health Organization (WHO) to ensure 90% of girls receive the HPV vaccine before turning 15, Bangladesh has recently started the (HPV) vaccine campaign nationwide. Therefore, our study aimed to assess the level of its acceptance among parents of eligible daughters in Bangladesh. Methods This nationwide cross-sectional study was conducted among the self-identified parents of daughters in the age group of 9–15 years between June 28 and August 2, 2023. A total of 2,151 parents were conveniently selected from all eight divisions of Bangladesh. Data was collected through face-to-face interviews using a semi-structured questionnaire. The Health Belief Model was used to appraise respondents’ beliefs concerning HPV and its vaccination. Adjusted odds ratios (AOR) with a corresponding 95% confidence interval (CI), and a p-value of <0.05 was considered statistically significant. R Studio (Version 2023.09.0+463) was used as an interface for data analysis, while R (the programming language) was used for statistical computations. Results The mean age of the study participants was 38.18 (±5.86) years. The overall acceptance rate of the HPV vaccine was 86.61% (95%CI: 85.09–88.02). The vaccine acceptance level was positively associated with all the domains of the HBM (p<0.001), except in the perceived barrier domain (p = 0.489). After adjustment for other factors, it was found that higher age was associated with a decreased acceptance (AOR: 0.92; 95% CI: 0.89–0.95). The urban residents exhibited 42% lower odds of vaccine acceptance than rural (AOR: 0.58; 95% CI: 0.36–0.92). Similarly, participants of the middle-income group had 44% lower odds than the lower-income group (AOR: 0.56; 95% CI: 0.32–0.97). Conclusion Our study found a reasonably good level of acceptance of the HPV vaccine among the parents of eligible daughters. Multiple factors such as younger age, urban residence, belonging to the middle income group, history of regular routine health check-ups, knowledge of cervical cancer, positive perception about benefits of the vaccine, and positive cues to actions were associated with HPV vaccine acceptance.

Coinfection of EBV with other pathogens: a narrative review

The Epstein-Barr viwrus (EBV) is a common herpesvirus that affects more than 90% of people worldwide. Even while EBV infections are frequently asymptomatic, they can cause autoimmune diseases and a number of cancers, especially in those with impaired immune systems. The intricate relationships between EBV and other coinfecting pathogens, including as human immunodeficiency virus (HIV), human papilloma virus (HPV), cytomegalovirus (CMV), and Plasmodium species, are examined in this study. We investigated the fundamental processes of these coinfections, their effects on the course of the disease, and their practical ramifications. The study reviewed how co-infections with EBV might modify immune responses, promote oncogenesis, and make treatment plans more challenging. In this review, we also discussed current therapeutic strategies, such as targeted molecular interventions, EBV vaccines, and adoptive T-cell therapy. The review underscores the need for more research to provide more focused and effective therapies that address the mutually reinforcing effects of numerous infections in disorders linked with EBV.

Oceanic Breakthroughs: Marine-Derived Innovations in Vaccination, Therapy, and Immune Health

The vast, untapped potential of the world’s oceans is revealing groundbreaking advancements in human health and vaccination. Microalgae such as Nannochloropsis spp. and Dunaliella salina are emerging as resources for recombinant vaccine development with specific and heterologous genetic tools used to boost production of functional recombinant antigens in Dunaliella salina and Nannochloropsis spp. to induce immunoprotection. In humans, several antigens produced in microalgae have shown potential in combating diseases caused by the human papillomavirus, human immunodeficiency virus, hepatitis B virus, influenza virus, Zika virus, Zaire Ebola virus, Plasmodium falciparum, and Staphylococcus aureus. For animals, microalgae-derived vaccine prototypes have been developed to fight against the foot-and-mouth disease virus, classical swine fever virus, vibriosis, white spot syndrome virus, and Histophilus somni. Marine organisms offer unique advantages, including the ability to express complex antigens and sustainable production. Additionally, the oceans provide an array of bioactive compounds that serve as therapeutics, potent adjuvants, delivery systems, and immunomodulatory agents. These innovations from the sea not only enhance vaccine efficacy but also contribute to broader immunological and general health. This review explores the transformative role of marine-derived substances in modern medicine, emphasizing their importance in the ongoing battle against infectious diseases.

Evaluation of a real-time optoelectronic method for the detection of cervical intraepithelial neoplasia and cervical cancer in patients with different transformation zone types

We aimed to evaluate the diagnostic value of TruScreen, a real-time diagnostic technology, for cervical lesions in patients with different transformation zone (TZ) types. A total of 1908 women aged 34.0 ± 7.3 years who have received cytology, human papillomavirus (HPV) testing, TruScreen, and colposcopy were recruited. The clinical performances of these tests were evaluated for their detection of high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ (AIS), or more severe lesions in patients with different TZ types. For the detection of HSIL, AIS, or more severe lesions, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TruScreen were 65.08%, 64.76%,11.55%, and 96.33%, respectively, which were similar to cytology (all P values > 0.05). For the detection of HSIL + in patients with type 3 TZ, the sensitivity, specificity, PPV, and NPV of TruScreen were 72.29%, 67.59%, 13.86%, and 97.13%, respectively, which were significantly higher than the sensitivity (51.16%, P = 0.029), specificity (59.59%, P = 0.001), PPV (7.94%, P = 0.016), and NPV (94.71%, P = 0.049) in type 1 and type 2 TZs. TruScreen has detection accuracy comparable to cytology and performs even better in patients with type 3 TZ.

Circulating tumor HPV DNA as a specific biomarker for cervical cancer

AbstractObjectiveThe aim of this study was to determine whether circulating tumor human papillomavirus (HPV) DNA is a potential specific biomarker for cervical cancer (CC).MethodsThis retrospective matched study included 87 patients with cervical intraepithelial neoplasia (CIN), 29 CC patients (FIGO IA1‐IVA) and 29 HPV‐negative controls at Yuhuangding Hospital of Qingdao University (from July 2022 to September 2023). The digital droplet PCR (ddPCR) was used to detect and quantify ctHPV DNA in the plasma of patients with HPV16, 18, 33, 52, or 58‐associated CC.ResultsThe ctHPV DNA was exclusively detectable in HPV‐positive samples, with no detection in patients across various CIN stages (n = 87) or HPV‐negative controls (n = 29). Additionally, ctHPV DNA was identified in nine out of 10 late‐stage patients (90%) and six out of 19 early‐stage patients (31.6%).ConclusionThe ctHPV DNA serves as a specific biomarker for the diagnosis CC. Additionally, this discovery addresses the knowledge gap in ctHPV DNA research in the early stages of CC and promotes clinical diagnosis and treatment strategies.

Immunogenicity Assessment of a 14-Valent Human Papillomavirus Vaccine Candidate in Mice

Background: Cervical cancer ranks as the fourth most common cancer affecting women globally, with HPV as the primary etiology agent. Prophylactic HPV vaccines have substantially reduced the incidence of cervical cancer. Methods: This study assessed the immunogenicity of SCT1000, a 14-valent recombinant virus-like particle (VLP) vaccine developed by Sinocelltech, Ltd. using pseudovirion-based neutralization assays (PBNAs) and total IgG Luminex immunoassays (LIAs). Currently in phase III clinical trials in China, SCT1000 targets the same HPV types as Gardasil 9®, plus five additional high-risk types, thereby covering twelve high-risk HPV types implicated in 96.4% of cervical cancer cases. Results: In murine models, a dose of 1.85 μg per mouse was identified as optimal for evaluating SCT1000’s immunogenicity in a three-dose regimen, as measured by PBNA and total IgG LIA across all 14 HPV types. SCT1000 induced high levels of protective antibodies, which were sustained for at least four months following the third dose. The vaccine also demonstrated stable and consistent immunogenicity in mouse potency assays under both long-term and accelerated conditions. Additionally, our studies revealed a strong correlation between the two serological tests used. Conclusions: SCT1000 elicited robust, durable, and consistent humoral immune responses across all 14 HPV types, indicating its potential as a broad-spectrum vaccine candidate against HPV types 6/11/16/18/31/33/35/39/45/51/52/56/58/59. The significant correlations observed between PBNA and total IgG LIA support the use of the Luminex-based total IgG method as a reliable and effective alternative for immunogenicity assessment in preclinical and future clinical vaccine development.

A Self-Amplifying Human Papillomavirus 16 Vaccine Candidate Delivered by Tobacco Mosaic Virus-Like Particles

A Self-Amplifying Human Papillomavirus 16 Vaccine Candidate Delivered by Tobacco Mosaic Virus-Like Particles

Status of HPV disease and vaccination programmes in LMICs: Introduction to special issue

Sexually transmitted human papillomavirus (HPV) infections are extremely common in both men and women and while most will clear naturally, some may progress to cervical cancer and other cancers. Despite the availability of prophylactic vaccines and well-established screening and treatment practices, the global burden of HPV-related disease remains high, particularly in low-and-middle-income countries (LMICs). We outline the current global epidemiology of cervical cancer disease incidence and mortality, with the highest burden in Africa and Asia. As part of a strategy to eliminate cervical cancer as a public health problem, the WHO recommends a 3-fold approach combining the use of prophylactic vaccines with cervical cancer screening and treatment. This overview focuses on the globally available HPV vaccines and current status of vaccine introduction in LMICs. We describe decreased HPV vaccination coverage in recent years and highlight the need for emphasis on new vaccine introductions and existing vaccine programme strengthening in order to reach goals for the elimination of cervical cancer as a public health problem. It is estimated that US$3.20 will be returned on each dollar invested in cervical cancer prevention efforts through 2050 [1]. Success for these initiatives centers on strategic vaccine delivery and collaborations that foster political support and engagement with civil society organisations and educational sector stakeholders. Recent increases in vaccine supply and single-dose efficacy evidence pave the way for cervical cancer elimination through vaccination coupled with screening and treatment. Subsequent manuscripts in this supplement will outline case studies and lessons from two symposia held in Africa and South Asia by the Coalition to Strengthen the HPV Immunization Community in 2022 including evidence for a one-dose strategy, the challenges of maintaining vaccine programmes during the COVID-19 pandemic, and progress in cervical cancer screening programmes.

Routine HPV vaccination: Reflection on delivery strategies based on countries’ experiences

Despite the introduction of the human papillomavirus (HPV) vaccine in many low- and middle-income countries (LMICs), countries are still struggling to maintain HPV vaccination coverage and manage sustainable delivery strategies. This article explores the challenges and effective strategies for HPV vaccine delivery in LMICs, with a focus on reflecting upon current HPV vaccine delivery strategies in the World Health Organization (WHO) HPV vaccine introduction guidelines to align with practical implementation experiences. The article utilizes presentations and discussions from Coalition to Strengthen the HPV Immunization Community (CHIC) symposia, field experiences of program implementers who participated in the meeting and immunization expert opinions, to inform its findings. Several countries are spotlighted for their delivery strategies. These include routinized campaign mode vaccinations at schools in The Gambia, Zambia, and Ethiopia; routine health facility services in Tanzania, Kenya, and Maldives; and outreach strategies targeting out-of-school girls. By evaluating these diverse strategies, the article suggests a need to delve deeper and build an understanding of the routinized campaign mode of HPV vaccine delivery, and advocates for expanding the scope of delivery strategies and consequently updating the WHO HPV vaccine delivery guidelines in line with the evolving landscape of HPV vaccination delivery to ensure comprehensive, cost-effective, and sustainable programs in LMICs.

Identifying key challenges and optimizing approaches for training of health care professionals for HPV vaccination programmes

Healthcare professionals (HCPs) play a crucial role in building vaccine confidence and promoting vaccination programmes. HCP vaccination recommendations are often the strongest predictor of vaccine uptake, influencing individuals' acceptance of and demand for vaccination. However, HCP training on human papillomavirus (HPV) vaccination faces challenges in some countries, including Ethiopia, Malawi, and Uganda. This study summarizes the discussions held during the Coalition to Strengthen HPV Immunization Community Symposium in Africa, the field experiences of co-authors, and expert opinions to inform its findings. Key challenges faced in these countries are maintaining regular and comprehensive HCP training, ensuring continuity due to staff turnover, reaching all health facilities, and including teachers as key mobilizers. Funding constraints, limited communication materials, and human resource shortages can further impact training effectiveness. Recommendations for strengthening HCP training on HPV vaccination programmes include providing adequate training to all HCPs, refresher training, including private sector HCPs and teachers, leveraging local training institutions, and integrating HPV vaccine training into pre-service HCP academic curricula. These actions would be essential for improving HPV vaccine coverage and working towards cervical cancer elimination goals.

Case studies on the progress of cervical cancer screening programs in Bhutan, India, and Türkiye

International stakeholders gathered in New Delhi, India, in December 2022 to share experiences on human papillomaviruses (HPV) prevention and control strategies. As part of a supplementary publication from the meeting proceedings, this paper describes secondary HPV prevention strategies highlighting the varying degrees of progress and challenges through case studies from Bhutan, India, and Türkiye. India has implemented national screening guidelines, primarily using visual inspection with acetic acid (VIA), but achieving a low coverage rate of 1.9% (2022). In contrast, Bhutan and Türkiye have redesigned and established HPV-based cervical screening programs targeting women aged 30–65, achieving 77% (2022) and 95% (2019) coverage among women ever screened, respectively. Lessons learned include utilising patient health information management systems, analysing optimal context-specific HPV testing strategies and ensuring use and continuous supply of clinically validated HPV tests.

Effective communication by health care workers to promote HPV vaccination: Lessons learned from Kenya, India, and Nigeria

Health care workers play an essential role in maintaining the public trust in vaccination programmes globally, and more specifically, in low- and middle-income countries. This role is particularly important in building trust in the human papillomavirus (HPV) vaccine. While there are many factors that affect HPV vaccine acceptance, health care workers are one of the most critical influences in the decision-making process among parents as well as adolescent girls. In this paper, we sought to better understand how health care workers in a diverse set of countries communicate and promote HPV vaccines. We summarize communication approaches and lessons learned by health care workers in Kenya, India, and Nigeria through a case study approach. In Kenya, the utilization of a multisectoral approach proved to be very important. In India, intense social mobilization with targeted messaging by target audience laid the groundwork for community acceptance. An evolving communication strategy was essential in Nigeria, where there is no national HPV vaccination programme. Given the increase in vaccine hesitancy globally, the lessons learned through these three country examples highlight the importance of communication efforts in increasing vaccine acceptance.

Evidence for an HPV one-dose schedule

The World Health Organization has recently updated their dosing schedule recommendations for the human papillomavirus (HPV) vaccine to include a single-dose schedule. We review the biologic plausibility of a single dose, the evidence from clinical trials, post-licensure observational studies, and mathematical modeling for a single-dose schedule. We also discuss the implications of countries switching to a single-dose program from a two or three-dose schedule. Finally, we review the countries that have currently switched to or introduced the vaccine with a single-dose schedule.

Effects of Message Framing on Human Papillomavirus Vaccination: Systematic Review

Background With the advancement of cervical cancer elimination strategies, promoting human papillomavirus (HPV) vaccination is essential to achieving this goal. The issue of how to structure and develop message content to promote HPV vaccination is a debatable issue. Objective The efficacy of gain-loss framing in vaccination contexts is disputed. Our study aimed to elucidate the consequences of message framing on attitudes, intentions, and behavioral tendencies toward HPV vaccination, with the objective of refining message framing strategies and their elements. Methods This systematic review adhered strictly to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guideline reporting standards to comprehensively retrieve, extract, and integrate data. We searched databases, including PubMed, Embase, Scopus, and Web of Science, for literature published from database construction to August 15, 2023. Literature screening, data extraction, and quality evaluation were performed by 2 researchers. Intervention studies published in English, conducted with populations with children eligible for HPV vaccination, and involving message framing were included. Attitudes, intentions, and behaviors served as outcome evaluation criteria. Results A total of 19 intervention studies were included. Gain-loss framing had no clear effect on vaccination attitudes nor intentions. Loss framing showed a weak advantage at improving HPV vaccination attitudes or intentions, but the evidence was not strong enough to draw definitive conclusions. The impact of gain-loss framing on HPV vaccination behaviors could not be determined due to the limited number of studies and the qualitative nature of the analysis. Conclusions Combining gain-loss framing with other message framing approaches may be an effective way to enhance the effect of message framing. More high-quality message framing content and exploring alternative moderator or mediator variables are required to support the conclusion. Trial Registration CRD42023451612; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=451612