Search Results (358)

Despite growing global momentum to reduce the number of children who never received a dose of any vaccine, i.e., zero-dose (ZD) children, persistent geographic and social inequities continue to undermine progress toward universal immunization coverage. In Madagascar, where routine vaccination coverage remains below 50% in most regions, the non-governmental organization Doctors for Madagascar and public sector partners are implementing the SOAMEVA program: a targeted community-based initiative to identify and reach ZD children in sixteen underserved districts in the country’s south. This paper outlines the equity-sensitive evaluation design developed to assess the implementation and impact of SOAMEVA. It presents a forward-looking evaluation framework that integrates both quantitative program monitoring and qualitative community insights. By focusing at the fokontany level—the smallest administrative unit in Madagascar—the evaluation captures small-scale variation in ZD prevalence and program reach, allowing for a detailed analysis of disparities often masked in aggregated data. Importantly, the evaluation includes structured feedback loops with community health workers and caregivers, surfacing local knowledge on barriers to immunization access and program adoption. It also tracks real-time adaptations to implementation strategy across diverse contexts, offering insight into how routine immunization programs can be made more responsive, sustainable, and equitable. We propose eight design principles for conducting equity-sensitive evaluation of immunization programs in similar fragile settings. Full article

In late 2019, a new virus, SARS-CoV-2, emerged in Wuhan, China, causing COVID-19 and the subsequent global pandemic. As of 30 April 2023, more than 774 million cases of COVID-19 had been reported worldwide, including over 7.5 million in Mexico. Despite advances in vaccination, epidemic surges of COVID-19 continued to occur globally, highlighting the importance of sharing and disseminating the experiences gained during these first years to better understand the virus’s evolution and respond accordingly. For this reason, the National Council for Science and Technology (CONACYT) organized the meeting “Challenges and Opportunities for Genomic Surveillance of SARS-CoV-2 in Mexico” from 15 to 17 August 2022, to present the efforts and results accumulated over more than two years of the pandemic. In this meeting report, we summarize the key findings of each participant and provide their contact information. Full article

Background: Zoonotic influenza viruses pose a significant and evolving public health threat. In response to the recent rise in H5N1 cross-species transmission, the World Health Organization (WHO) R&D Blueprint for Epidemics consultations have prioritized strengthening surveillance, candidate vaccines, diagnostics, and pandemic preparedness. Serological surveillance plays a pivotal role by providing insights into the prevalence and transmission dynamics of influenza viruses. Objective: This scoping review aimed to map the global research landscape on serological surveillance of zoonotic influenza in animals and exposed humans between 2017, the date of the last WHO public health research agenda for influenza review, and 2024, as well as to identify methodological advancements. Methods: Following PRISMA-ScR guidelines, we searched PubMed for English-language peer-reviewed articles published between January 2017 and March 2024. Studies were included if they reported serological surveillance in wild or domestic animals or occupationally exposed human populations, or novel methodologies and their technical limitations and implementation challenges. Results: Out of 7490 screened records, 90 studies from 33 countries, covering 25 animal species, were included. Seroprevalence studies were in domestic poultry and swine. Surveillance in companion animals, wild mammals, and at the human–animal interface was limited. Emerging serological methods included multiplex and nanobody-based assays, though implementation barriers remain. Conclusions: The review is limited by its restriction to one database and English-language articles, lack of quality appraisal, and significant heterogeneity among the included studies. Serological surveillance is a critical but underutilized tool in zoonotic influenza monitoring. Greater integration of serological surveillance into One Health frameworks, especially in high-risk regions and populations, is needed to support early detection and pandemic preparedness. Full article

Background/Objectives: Opioid use disorder (OUD) remains a severe health problem globally, resulting in substantial social and economic challenges. While existing medications for managing OUD are proven to be effective, they also present certain challenges. A vaccine offers a promising therapeutic strategy to combat OUD and potentially reduce the risk of overdose death. The TT-6-AmHap heroin conjugate vaccine has effectively reduced heroin-induced pharmacological effects in behavioral assays as well as demonstrated the induction of high titer and high affinity antibody responses in mice and rats. In this GLP study conducted in rabbits, the potential local and systemic toxicity of the TT-6-AmHap heroin vaccine in combination with or without adjuvants ALF43 and Alhydrogel^® (ALFA) was investigated. Methods: Male and female New Zealand White rabbits were administered with vaccines or a saline control intramuscularly at two-week intervals over a 57-day study period. The presence, persistence or reversibility of any toxic effects of the vaccine was determined over a four-week recovery period. Results: Administration of TT-6-AmHap with or without the adjuvants induced high antibody-specific IgG in treatment groups compared to the controls. The study found no TT-6-AmHap-related effects on mortality, physical examinations, dermal Draize observations, body weights, body weight changes, food consumption, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, and urinalysis), macroscopic pathology, or organ weights. Conclusions: Under the conditions of this study, these results demonstrate that the TT-6-AmHap vaccine with or without adjuvants was well tolerated, immunogenic, and the effects were not considered adverse in both male and female rabbits. Full article

Cervical cancer remains a significant global public health challenge, with human papillomavirus (HPV) as its primary cause. In response, the World Health Organization (WHO) launched a global strategy to eliminate cervical cancer by 2030 and, in its 2022 position paper, recommended a single-dose vaccination schedule. The objective of this review is to critically examine the current HPV vaccination landscape in China, including vaccination policies, immunization schedules, supply–demand dynamics, and the feasibility of transitioning to a single-dose regimen. By synthesizing recent developments in HPV virology, epidemiology, vaccine types, and immunization strategies, we identify both opportunities and barriers unique to the Chinese context. Results indicate that China primarily adheres to a three-dose vaccination schedule, with an optional two-dose schedule for girls aged 9–14, leaving a notable gap compared to the most recent WHO recommendation. The high prevalence of HPV types 52 and 58 contributes to a distinct regional infection pattern, underscoring the specific need for nine-valent vaccines tailored to China’s epidemiological profile. Despite the growing demand, vaccine supply remains inadequate, with an estimated annual shortfall of more than 15 million doses. This issue is further complicated by strong public preference for the nine-valent vaccine and the relatively high cost of vaccination. Emerging evidence supports the comparable efficacy and durable protection of a single-dose schedule, which could substantially reduce financial and logistical burdens while expanding coverage. This review advocates for the adoption of a simplified single-dose regimen, supported by catch-up strategies for older cohorts and the integration of HPV vaccination into China’s National Immunization Program (NIP). Sustained investment in domestic vaccine development and centralized procurement of imported vaccines may also possibly alleviate supply shortage. These coordinated efforts are critical for strengthening HPV-related disease prevention and accelerating China’s progress toward the WHO’s cervical cancer elimination targets. Full article

Background: Since the introduction of Pasteur’s rabies vaccine in 1885, rabies prophylaxis and post-exposure prophylaxis (PEP) have been widely administered globally under the recommendation of the World Health Organization (WHO). However, 124 documented cases of PEP failure had been reported worldwide between 1980 and 2023. Additionally, sporadic media reports from China showed occasional PEP failures between 2017 and 2024. Rabies remains a serious public health problem in over 150 countries and regions. Methods: In this review, we summarize PEP procedures recommended by the Advisory Committee on Immunization Practices (ACIP) and the WHO. We also analyze potential contributing factors to PEP failure, propose a concept of circulating antibodies, and discuss their roles in PEP. Furthermore, we summarize key guidelines for clinical trial design from the U.S. Food and Drug Administration (FDA) and China’s Center for Drug Evaluation (CDE), as well as the latest developments in monoclonal antibody (cocktail) therapies. Results: Adherence to core PEP practices, such as wound cleansing, infiltration of wounds with immunoglobulin (mAbs), and administration of vaccines, and broader societal involvement are crucial for preventing rabies infection in most cases. For high-risk exposures or immunocompromised individuals, the provision of circulating antibodies through high-dose human rabies immune globulin (HRIG) or mAbs is of utmost importance for preventing PEP failure. Conclusions: Early, high-concentration circulating antibodies are important for preventing PEP failure. Addressing the global issue of rabies requires involvement of the entire society. Only through collective efforts can we tackle this neglected disease and achieve WHO’s goal of “zero by 30”. Full article

The 100-Day Mission, coordinated by the Coalition for Epidemic Preparedness Innovations (CEPI) and endorsed by significant international stakeholders, aims to shorten the timeframe for developing and implementing vaccines to 100 days after the report of a new pathogen. This ambitious goal is outlined as an essential first step in improving pandemic preparedness worldwide. This review highlights the mission’s implementation potential and challenges by examining it through the lens of low- and middle-income countries (LMICs), which often face barriers to equitable vaccine access. This article explores the scientific, economic, political, and social aspects that could influence the mission’s success, relying on lessons learned from previous pandemics, such as the Spanish flu, H1N1, and COVID-19. We also examined important cornerstones like prototype vaccine libraries, accelerated clinical trial preparedness, early biomarkers identification, scalable manufacturing capabilities, and rapid pathogen characterization. The review also explores the World Health Organization (WHO) Pandemic Agreement and the significance of Phase 4 surveillance in ensuring vaccine safety. We additionally evaluate societal issues that disproportionately impact LMICs, like vaccine reluctance, health literacy gaps, and digital access limitations. Without intentional attempts to incorporate under-resourced regions into global preparedness frameworks, we argue that the 100-Day Mission carries the risk of exacerbating already-existing disparities. Ultimately, our analysis emphasizes that success will not only rely on a scientific innovation but also on sustained international collaboration, transparent governance, and equitable funding that prioritizes inclusion from the beginning. Full article

Background: Cervical cancer is a major global health concern, causing approximately 350,000 deaths annually. It is also preventable through effective prevention and early detection. To facilitate elimination, the World Health Organization (WHO) set targets for HPV vaccination, screening, and treatment. Achieving these goals requires frameworks to monitor screening program performance. As many regions transition to HPV primary screening, a standardized Cervical Cancer Screening Cascade can track performance, identify gaps in follow-up, and optimize resource allocation. Methods: This paper introduces a structured cascade developed to monitor uptake, retention, and outcomes in HPV-based screening programs. The Cascade was created through collaboration between public health experts, clinicians, and researchers at the University of British Columbia (UBC), the Women’s Health Research Institute, and BC Cancer. Results: The Cascade outlines four phases: screening, triage, detection, and treatment. Each phase includes two substages: “uptake” and “results,” with an additional substage in screening (“invitation”). “Screening” assesses invitation effectiveness and participation. “Triage” tracks follow-up after a positive screen. “Detection” evaluates attendance at diagnostic appointments, and “Treatment” measures the treatment rate for those with precancerous lesions. Conclusions: The Cascade can guide emerging and existing HPV screening programs within Canada and other similarly resourced settings and serve as a benchmark tool for programs to assess their progress towards cervical cancer elimination. Full article

The emergence of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus closely related to SARS-CoV and officially known as Betacoronavirus pandemicum precipitated a substantial surge in vaccine development that culminated during the global COVID-19 pandemic. At present, there are dozens of vaccines for the prevention of SARS-CoV-2 being utilized across the globe. However, only 10 of these vaccines have been authorized by the World Health Organization (WHO). These include mRNA-based, viral vector, subunit and whole-virion inactivated vaccines. At the current end of the pandemic, there has been a decline in the global vaccination rate, both for the general population and for those most at risk of severe illness from the virus. This suggests that the effectiveness of the vaccines may be waning. The decline occurs alongside a decrease in testing and sequencing for SARS-CoV-2. Furthermore, the process of tracking viruses becomes increasingly complex, thereby providing a selective advantage for SARS-CoV-2 and allowing it to evolve stealthily. In this review, we provide a comprehensive overview of viral evolution and vaccine development. We also discuss ways to overcome viral variability and test universal vaccines for all SARS-CoV-2 variants. Full article

Livestock farming is a vital component of global food security, yet it remains a major contributor to greenhouse gas (GHG) emissions, particularly methane (CH₄), which has a global warming potential 28 times greater than carbon dioxide (CO₂). This review provides a comprehensive synthesis of current knowledge surrounding the sources, biological mechanisms, and mitigation strategies related to CH₄ emissions from ruminant livestock. We first explore the process of methanogenesis within the rumen, detailing the role of methanogenic archaea and the environmental factors influencing CH₄ production. A thorough assessment of both direct and indirect methods used to quantify CH₄ emissions is presented, including in vitro techniques (e.g., syringe method, batch culture, RUSITEC), in vivo techniques (e.g., respiration chambers, Greenfeed, laser CH₄ detectors), and statistical modeling approaches. The advantages and limitations of each method are critically analyzed in terms of accuracy, cost, feasibility, and applicability to different farming systems. We then examine a wide range of mitigation strategies, organized into four core pillars: (1) animal and feed management (e.g., genetic selection, pasture quality improvement), (2) diet formulation (e.g., feed additives such as oils, tannins, saponins, and seaweed), (3) rumen manipulation (e.g., probiotics, ionophores, defaunation, vaccination), and (4) manure management practices and policy-level interventions. These strategies are evaluated not only for their environmental impact but also for their economic and practical viability in diverse livestock systems. By integrating technological innovations with sustainable agricultural practices, this review highlights pathways to reduce CH₄ emissions while maintaining animal productivity. It aims to support decision-makers, researchers, and livestock producers in the global effort to transition toward climate-smart, low-emission livestock farming. Full article

The H5N1 avian influenza virus continues to evolve into genetically diverse and highly pathogenic clades with increased potential for cross-species transmission. Recent scientific advances have included the development of next-generation vaccine platforms, promising antiviral compounds, and more sensitive diagnostic tools, alongside strengthened surveillance systems in both animals and humans. However, persistent structural challenges hinder global readiness. Vaccine production is heavily concentrated in high-income countries, limiting equitable access during potential pandemics. Economic and logistical barriers complicate the implementation of control strategies such as vaccination, culling, and compensation schemes. Gaps in international coordination, public communication, and standardization of protocols further exacerbate vulnerabilities. Although sustained human-to-human transmission has not been documented, the severity of confirmed infections and the rapid global spread among wildlife and domestic animals underscore the urgent need for robust preparedness. International organizations have called for comprehensive pandemic response plans, enhanced multisectoral collaboration, and investment in targeted research. Priorities include expanding surveillance to asymptomatic animal hosts, evaluating viral shedding and transmission routes, and developing strain-specific and universal vaccines. Strengthening global cooperation and public health infrastructure will be critical to mitigate the growing threat of H5N1 and reduce the risk of a future influenza pandemic. Full article

Cervical cancer remains one of the main causes of female mortality, especially in middle- and low-income countries, despite efforts towards the implementation of global vaccination against human papillomavirus (HPV). The aim of this study was to review and compare the most recently published international guidelines providing recommendations on cervical cancer screening strategies among average and high-risk women. Thus, a comparative review of guidelines by the US Preventive Services Task Force (USPSTF), the American Cancer Society (ACS), the American Society of Clinical Oncology (ASCO), the World Health Organization (WHO), the Canadian Task Force on Preventive Health Care (CTFPHC), the Cancer Council Australia (CCA), and the European Guidelines (EG) was conducted. There is an overall agreement regarding the suggestions made for women younger than 21 and those older than 65, with all guidelines stating against routine screening, with the exceptions of CTFPHC and CCA that expand the age group to up to 70 and 75 years, respectively. Continuation of screening in older women is also suggested in those with a history of a precancerous lesion and those with inadequate screening. Most guidelines recommend routine screening at 30–65 years, while the WHO advises that screening should be prioritized at 30–49 years. HPV DNA testing is the method of choice recommended by most guidelines, followed by cytology as an alternative, except for CTFPHC, which refers to cytology only, with self-sampling being an acceptable method by most medical societies. Agreements exist regarding recommendations for specific groups, such as women with a history of total hysterectomy for benign reasons, women with a complete vaccination against HPV, individuals from the lesbian, gay, bisexual, transgender, and queer communities and women with multiple sexual partners or early initiation of sexual activity. On the other hand, the age group of 21–29 is addressed differently by the reviewed guidelines, while differentiations also occur in the screening strategies in cases of abnormal screening results, in women with immunodeficiency, those with in utero exposure to diethylstilbestrole and pregnant women. The development of consistent practice protocols for the most appropriate cervical cancer screening programs seems to be of major importance to reduce mortality rates and safely guide everyday clinical practice. Full article

The World Health Organization (WHO) Global Benchmarking Tool (GBT) classifies regulatory systems into four maturity levels, with Maturity Level 3 (ML3) signifying a stable and effective regulatory environment. As of January 2025, eight African nations—Egypt, Ghana, Nigeria, Rwanda, Senegal, South Africa, Tanzania, and Zimbabwe—have attained ML3 status, marking a significant milestone in the continent’s regulatory landscape. Achieving ML3 confers critical benefits, including reducing substandard and falsified medicines, which enhances public health safety and fosters trust in healthcare systems. This progress encourages local manufacturing, diminishing reliance on imported medicines and promoting economic development. Furthermore, ML3 NRAs are better equipped to address public health emergencies, enabling swift approvals for vaccines and therapeutics while upholding safety standards. Nonetheless, challenges persist, including fragmented regulatory systems, the prevalence of counterfeit medicines, and limited resources. Overcoming these hurdles necessitates enhanced organizational capacity, investments in training, and the promotion of collaboration among NRAs. There is an urgent call for greater political commitment and resource allocation to strengthen regulatory systems across Africa. Achieving and maintaining ML3 status is essential for enhancing medicine regulation, supporting local manufacturing, and improving public health outcomes across the continent. While progress has been made, sustained efforts are crucial to tackling existing challenges and harnessing the full potential of advanced regulatory frameworks. Full article

Background/Objectives: Vaccine hesitancy is one of the top ten threats to global health. It is necessary to develop appropriate strategies to address vaccine hesitancy. This systematic review aimed to analyze strategies used to improve the acceptance of vaccines, address doubts, and/or increase confidence and motivation in routine vaccination across all age groups. Methods: A systematic review was conducted of the MEDLINE, Dialnet, Scielo, CINAHL, and CENTRAL databases between 2018 and 2023. The inclusion criterion was full-text studies in English or Spanish that improve the degree of acceptance of vaccines and were evaluated by vaccination rate or pre- or postintervention tests. For data extraction, each study was categorized as community education, tailored messages, media, and new technologies. Results: A total of 1938 studies were identified, 38 of which were selected. New technology-based interventions used in the adult population for several vaccines offer broad reach, user interaction, and data accessibility. Tailored message strategies were used mainly among parents to foster strong relationships through respectful and empathetic dialog. Community education programs were targeted mainly at adolescents, emphasizing the use of structured, appropriate and interactive materials. Media campaigns were used as a support strategy for community education and new technology strategies due to their simplicity, wide coverage, and reach. Conclusions: The best strategies for reducing hesitancy are multicomponent interventions with structured and organized educational content based on the reasons for hesitancy and tailored to the target population. Therefore, caution must be taken when applying interventions, given that no single strategy can address this issue. Full article

Nipah virus (NiV) is a highly pathogenic paramyxovirus characterized by zoonotic infection, high mortality, and a lack of effective treatment, posing a serious threat to global public health security. Currently, it still lacks specific treatments or approved vaccines, and is listed as a potential pandemic threat pathogen by the World Health Organization. This paper systematically reviews the core progress and challenges of NiV investigation, with a focus on the development of animal models, vaccine development strategies, treatment strategy, and bottlenecks in translational medicine. Additionally, we discuss the strengths and limitations of existing animal models, including ferrets, hamsters, mice, and non-human primates (NHPs), and assess advances in vaccine platforms such as viral vectors, subunit vaccines, and mRNA-based vaccine candidates. The paper critically reviews the challenges facing translational research, conservation correlates, and outbreak preparedness, while also providing future research directions for pandemic preparedness and public health security strategies. Full article