Search Results (102)

Background/Objectives: Syphilis, a re-emerging global public health issue, has shown increasing incidence over the past decade, particularly among key populations such as men who have sex with men (MSM), people living with HIV, and pregnant women. This narrative review aimed to synthesize global epidemiological trends of syphilis from 2015 to 2025, with a focus on surveillance gaps, regional disparities, and structural determinants. Methods: A broad narrative approach was used to collect and analyze epidemiological data from 2015 to 2025. The literature was retrieved from databases (PubMed, Scopus) and official reports from the WHO, CDC, and ECDC. Included materials span observational studies, surveillance reports, and modeling data relevant to global trends and public health responses. Results: Globally, syphilis incidence has increased, with notable surges in North America, Europe, and Asia. MSM remain disproportionately affected, while congenital syphilis is resurging even in high-income countries. Low- and middle-income countries report persistent burdens, especially among women of reproductive age, often exacerbated by limited screening and surveillance infrastructure. The COVID-19 pandemic disrupted syphilis-related services and further exacerbated underreporting, hindering timely detection and response efforts. Surveillance systems vary widely in their completeness and quality, which significantly hinders global data comparability and coordinated public health responses. Conclusions: Despite its curability, syphilis continues to spread due to fragmented prevention strategies, inequities in access to care, and insufficient surveillance. Strengthening diagnostic access, integrating prevention efforts into broader health systems, and addressing social determinants are essential. Improved surveillance, equitable access, and innovation—including diagnostics and potential vaccine research—are critical to controlling the global syphilis epidemic. Full article

In April 2024, a hybrid meeting organized by the WHO, PAHO, and MPP during the World Bank Spring Meetings focused on financing mRNA-based technologies in Low- and Middle-Income Countries (LMICs). This meeting sought to engage multilateral development banks (MDBs) and stakeholders in financing the expansion of vaccine production and enhancing pandemic preparedness. The COVID-19 pandemic underscored the disparities in vaccine production and distribution, highlighting the need for localized production to improve global health equity. The WHO’s mRNA Technology Transfer Programme, initiated in 2021, aims to build local capacity for mRNA vaccine development and manufacturing. Key sessions covered during the meeting include innovative investment models, with MDBs discussing funding instruments and the necessity of an integrated ecosystem for sustainable vaccine manufacturing. Challenges such as technological risks and the need for higher risk appetite were addressed, along with innovative financing mechanisms like blended financing. An analysis of capital and operational expenditures for mRNA vaccine facilities was presented, projecting significant production capacity in LMICs within a decade. Panelists emphasized the need for sustainable R&D investment and shared experiences in securing funding for mRNA technology. The meeting underscored the importance of collaboration, innovative financing, ecosystem development, and public–private partnerships, marking a pivotal step towards advancing mRNA technology in LMICs to tackle global health challenges. Full article

Background: The emergence of more than 40 new infectious diseases since the 1980s has emerged as a serious global health concern, many of which are zoonotic. In response, many international organizations, including the US Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), and the European Center for Disease Prevention and Control (ECDC), have developed strategies to combat these health threats. The need for rapid vaccine development has been highlighted by Coronavirus disease 2019 (COVID-19), and mRNA technology has shown promise as a platform. While the acceleration of vaccine development has been successful, concerns have been raised about the technical limits, safety, supply, and distribution of vaccines. Objective: This study analyzes the status of vaccine platform development in global pandemics and explores ways to respond to future pandemic crises through an overview of the roles of international organizations and their support programs. It examines the key roles and partnerships of international organizations such as the World Health Organization (WHO), vaccine research and development expertise of the Coalition for Epidemic Preparedness Innovations (CEPI), control of the vaccine supply chain and distribution by the Global Alliance for Vaccines and Immunization (GAVI), and technology transfer capabilities of the International Vaccine Institute (IVI) in supporting the development, production, and supply of vaccine platform technologies for pandemic priority diseases announced by WHO and CEPI and analyzes their vaccine support programs and policies to identify effective ways to rapidly respond to future pandemics caused by emerging infectious diseases. Methods: This study focused on vaccine platform technology and the key roles of international organizations in the pandemic crisis. Literature data on vaccine platform development was collected, compared, and analyzed through national and international literature data search sites, referring to articles, journals, research reports, publications, books, guidelines, clinical trial data, and related reports. In addition, the websites of international vaccine support organizations, such as WHO, CEPI, GAVI, and IVI, were used to examine vaccine support projects, initiatives, and collaborations through literature reviews and case study methods. Results: The COVID-19 pandemic brought focus on the necessity for developing innovative vaccine platforms. Despite initial concerns, the swift integration of cutting-edge development technologies, mass production capabilities, and global collaboration have made messenger RNA (mRNA) vaccines a game-changing technology. As a result of the successful application of novel vaccine platforms, it is important to address the remaining challenges, including technical limits, safety concerns, and equitable global distribution. To achieve this, it is essential to review the regulatory, policy, and support initiatives that have been implemented in response to the COVID-19 pandemic, with particular emphasis on the key stages of vaccine development, production, and distribution, to prepare for future pandemics. An analysis of the status of vaccine development for priority pandemic diseases implies the need for balanced vaccine platform development. Also, international organizations such as WHO, CEPI, GAVI, and IVI play key roles in pandemic preparedness and the development and distribution of preventive vaccines. These organizations collaborated to improve accessibility to vaccines, strengthen the global response to infectious diseases, and address global health issues. The COVID-19 pandemic response demonstrates how the synergistic collaboration of WHO’s standardized guidelines, CEPI’s vaccine research and development expertise, GAVI’s control of the vaccine supply chain and distribution, and IVI’s technology transfer capabilities can be united to create a successful process for vaccine development and distribution. Conclusions: In preparation for future pandemics, a balanced vaccine platform development is essential. It should include a balanced investment in both novel technologies such as mRNA and viral vector-based vaccines and traditional platforms. The goal is to develop vaccine platform technologies that can be applied to emerging infectious diseases efficiently and increase manufacturing and distribution capabilities for future pandemics. Moreover, international vaccine support organizations should play key roles in setting the direction of global networking and preparing for international vaccine support programs to address the limitations of previous pandemic responses. As a result, by transforming future pandemic threats from unpredictable crises to surmountable challenges, it is expected to strengthen global health systems and reduce the social and economic burden of emerging infectious diseases in the long term. Full article

Background/Objectives: In November 1999, WHO established the Strategic Advisory Group of Experts (SAGE) on Immunization as a multidisciplinary group of experts to provide high-level recommendations on vaccines and immunization. Methods: This review provides an overview of SAGE’s work in the past 25 years. It further outlines the processes and methods currently used by SAGE and highlights some of its major achievements. Results: SAGE’s global policies have driven action toward eradication, elimination and disease control and addressed the optimization of vaccination and immunization. In total, 27 major policy positions on vaccines/vaccine-preventable diseases have guided global public health. During times of epidemics and pandemics, interim recommendations issued by SAGE have responded iteratively in real-time to provide evidence-driven response policies. SAGE is an adaptive advisory group that has modified its procedures and working approaches to meet the evolving challenges in public health and stay up-to-date with evolving scientific and guideline development standards. Conclusions: Over the last quarter century, SAGE has significantly contributed to shaping the immunization landscape. It has achieved and maintained a high level of integrity and credibility. The advisory group continues to be an authority in global public health, and its recommendations have profound implications for the health of individuals and populations across the globe. Full article

COVID-19 is an enveloped virus with a single-stranded $RNA$ genome. The surface of the virus contains spike proteins, which enable the virus to attach to host cells and enter the interior of the cells. After entering the cell, the virus exploits the host cell’s mechanisms for replication and dissemination. Since the end of 2019, COVID-19 has spread rapidly around the world, leading to a large-scale epidemic. In response to the COVID-19 pandemic, the global scientific community quickly launched vaccine research and development. Vaccination is regarded as a crucial strategy for controlling viral transmission and mitigating severe cases. In this paper, we propose a novel mathematical model for COVID-19 infection incorporating vaccine-induced immunization failure. As a cornerstone of infectious disease prevention measures, vaccination stands as the most effective and efficient strategy for curtailing disease transmission. Nevertheless, even with vaccination, the occurrence of vaccine immunization failure is not uncommon. This necessitates a comprehensive understanding and consideration of vaccine effectiveness in epidemiological models and public health strategies. In this paper, the basic regeneration number is calculated by the next generation matrix method, and the local and global asymptotic stability of disease-free equilibrium point and endemic equilibrium point are proven by methods such as the Routh–Hurwitz criterion and Lyapunov functions. Additionally, we conduct fractional-order numerical simulations to verify that order $0.86$ provides the best fit with COVID-19 data. This study sheds light on the roles of immunization failure and fractional-order control. Full article

One of the greatest success stories of modern medicine is the prevention of infectious diseases by vaccination, most notably against smallpox and poliomyelitis. However, recent events, such as the 2009–2010 swine flu and the 2020 COVID-19 pandemics, as well as the continued emergence of highly pathogenic avian influenza viruses highlighted the fact that we still need to develop new vaccines, and perhaps we should be proactive, rather than reacting to epidemics and pandemics. However, the development of tools for evaluating novel vaccines has not been able to keep up with the rate of vaccine production. Humoral and cellular immune responses to vaccination have both been suggested to be important in preventing infections or ameliorating their consequences, although there is uncertainty regarding their exact roles and importance. This, together with the rapid development of new vaccines, means that the need for developing immunogenicity parameters, and even more importantly, reliable correlates of protection, is more important than ever. Full article

Background: Although confirmed cases of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been declining since late 2020 due to general vaccination, little research has been performed regarding the impact of vaccines against SARS-CoV-2 in Spain in terms of hospitalizations and deaths. Objective: Our aim was to identify the reduction in severity and mortality of coronavirus disease 2019 (COVID-19) at a nationwide level due to vaccination. Methods: We designed a retrospective, population-based study to define waves of infection and to describe the characteristics of the hospitalized population. We also studied the rollout of vaccination and its relationship with the decline in hospitalizations and deaths. Finally, we developed two mathematical models to estimate non-vaccination scenarios using machine learning modeling (with the ElasticNet and RandomForest algorithms). The vaccination and non-vaccination scenarios were eventually compared to estimate the number of averted hospitalizations and deaths. Results: In total, 498,789 patients were included, with a global mortality of 14.3%. We identified six waves or epidemic outbreaks during the observed period. We established a strong relationship between the beginning of vaccination and the decline in both hospitalizations and deaths due to COVID-19 in all age groups. We also estimated that vaccination prevented 170,959 hospitalizations (CI 95% 77,844–264,075) and 24,546 deaths (CI 95% 2548–46,543) in Spain between March 2021 and December 2021. We estimated a global reduction of 9.19% in total deaths during the first year of COVID-19 vaccination. Conclusions: Demographic and clinical profiles changed over the first months of the pandemic. In Spain, patients over 80 years old and other age groups obtained clinical benefit from early vaccination. The severity of COVID-19, in terms of hospitalizations and deaths, decreased due to vaccination. Our use of machine learning models provided a detailed estimation of the averted burden of the pandemic, demonstrating the effectiveness of vaccination at a population-wide level. Full article

Influenza A virus (IAV) poses a global threat worldwide causing pandemics, epidemics, and seasonal outbreaks. Annual modification of vaccines is costly due to continual shifts in circulating genotypes, leading to inadequate coverage in low- and middle-income countries like India. Additionally, IAVs are evolving resistance to approved antivirals, necessitating a search for alternative treatments. In this study, the antiviral role of the FDA-approved antibiotic minocycline against IAV strains was evaluated in vitro and in vivo by quantifying viral gene expression by qRT-PCR, viral protein levels by Western blotting, and viral titers. Our findings demonstrate that minocycline at a non-toxic dose effectively inhibits IAV replication, regardless of viral strain or cell line. Its antiviral mechanism operates independently of interferon signaling by targeting the MEK/ERK signaling pathway, which is crucial for the export of viral ribonucleoproteins (vRNPs). Minocycline prevents the assembly and release of infectious viral particles by causing the accumulation of vRNPs within the nucleus. Moreover, minocycline also inhibits IAV-induced late-stage apoptosis, further suppressing viral propagation. The antiviral activity of minocycline against IAVs could offer a promising solution amidst the challenges posed by influenza and the limitations of current treatments. Full article

As a typical case of the optimal planning for the provision of restricted medical resources, widespread vaccination is considered an effective and sustainable way to prevent and control large-scale novel coronavirus disease 2019 (COVID-19) outbreaks. However, an initial supply shortage of vaccines is inevitable because of the narrow production and logistical capacity. This work focuses on the multi-type vaccine resource allocation problem in a two-dose vaccination campaign under limited supply. To address this issue, we extended an age-stratified susceptible, exposed, infectious, and recovered (SEIR) epidemiological model to incorporate a two-dose vaccination campaign involving multiple vaccine types to fully characterize the various stages of infection and vaccination. Afterward, we integrated the proposed epidemiological model into a nonlinear programming (NLP) model to determine the optimal allocation strategy under supply capacity and vaccine hesitancy constraints with the goal of minimizing the cumulative number of deaths due to the pandemic over the entire planning horizon. A case study based on real-world data from the initial mass vaccination campaign against COVID-19 in the Midlands, England, was taken to validate the applicability of our model. Then, we performed a comparative study to demonstrate the performance of the proposed method and conducted an extensive sensitivity analysis on critical model parameters. Our results indicate that prioritizing the allocation of vaccines to elderly persons is an effective strategy for reducing COVID-19-related fatalities. Furthermore, we found that vaccination alone will not be sufficient for epidemic control in the short term, and appropriate non-pharmacological interventions are still important for effective viral containment during the initial vaccine rollout. The results also showed that the relative efficacy of the first dose is a vital factor affecting the optimal interval between doses. It is always best to complete the two-dose vaccination schedule as soon as possible when the relative efficacy of the first dose is low. Conversely, delaying the second dose of a vaccine as long as possible to increase the proportion of the population vaccinated with a single dose tends to be more favorable when the relative efficacy of the first dose is high. Finally, our proposed model is general and easily extendable to the study of other infectious disease outbreaks and provides important implications for public health authorities seeking to develop effective vaccine allocation strategies for tackling possible future pandemics. Full article

Seasonal influenza is an acute respiratory infectious disease due to influenza viruses, causing a relevant number of illnesses and deaths each year worldwide. Influenza is a preventable disease by vaccination. The aim of this study was to assess the epidemiology of seasonal influenza in Italy through the analysis of data from the epidemiological and virological RespiVirNet surveillance system for the season 2010/2011 to 2023/2024 to identify the epidemiological key points to plan the most appropriate vaccination strategies. The cumulative and maximum weekly incidence of influenza-like illness (ILI) and epidemic period (beginning, end, duration in weeks) were assessed in the pre-pandemic period (2010/2011–2019/2020) and they were compared to the pandemic and post-pandemic one. In all seasons, children reported the highest incidence values of ILI and longer epidemic periods in contrast with the older population. The epidemic seasons 2020/2021 and 2021/2022 had abnormal trends while in the last seasons 2022/2023 and 2023/2024 the epidemiological and virological trends of ILI were confirmed as reported in the pre-pandemic period but with high intensity. Influenza virus A was predominant: the H3N2 subtype circulated more than virus H1N1pdm09. In the few seasons when influenza virus B was the most frequent influenza agent, it co-circulated with influenza virus A. The monitoring of cases is the fundamental tool to better understand the epidemiology of influenza and to optimize future preventive strategies. Full article

Genomic surveillance based on sequencing the entire genetic code of SARS-CoV-2 involves monitoring and studying genetic changes and variations in disease-causing organisms such as viruses and bacteria. By tracing the virus, it is possible to prevent epidemic spread in the community, ensuring a ‘precision public health’ strategy. A peptide-based design was applied to provide an efficacious strategy that is able to counteract any emerging viral variant of concern dynamically and promptly to affect the outcomes of a pandemic at an early stage while waiting for the production of the anti-variant-specific vaccine, which require longer times. The inhibition of the interaction between the receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and one of the cellular receptors (DPP4) that its receptors routinely bind to infect human cells is an intriguing therapeutic approach to prevent the virus from entering human cells. Among the other modalities developed for this purpose, peptides surely offer unique advantages, including ease of synthesis, serum stability, low immunogenicity and toxicity, and small production and distribution chain costs. Here, we obtained a potent new inhibitor based on the rearrangement of a previously identified peptide that has been rationally designed on a cell dipeptidyl peptidase 4 (DPP4) sequence, a ubiquitous membrane protein known to bind the RBD-SPIKE domain of the virus. This novel peptide (named DPP4-derived), conceived as an endogenous “drug”, is capable of targeting the latest tested variants with a high affinity, reducing the VSV* DG-Fluc pseudovirus Omicron’s infection capacity by up to 14%, as revealed by in vitro testing in human Calu-3 cells. Surface plasmon resonance (SPR) confirmed the binding affinity of the new DPP4-derived peptide with Omicron variant RBD. Full article

No vaccine has been more effective in reducing disease burden, especially in preventing child deaths, than measles-containing vaccine. The return on investment makes measles-containing vaccine one of the most cost-effective public health measures available. Exhaustive reviews of biological, technical, economic and programmatic evidence have concluded that measles can and should be eradicated, and by including rubella antigen in measles-containing vaccine, congenital rubella syndrome will also be eradicated. All World Health Organisation Regions have pledged to achieve measles elimination. Unfortunately, not all countries and global partners have demonstrated an appropriate commitment to these laudable public health goals, and the negative impact of the COVID-19 pandemic on coverage rates has been profound. Unsurprisingly, large disruptive outbreaks are already occurring in many countries with a global epidemic curve ominously similar to that of 2018/2019 emerging. The Immunization Agenda 2030 will fail dismally unless measles and rubella eradication efforts are accelerated. Over half of all member states have been verified to have eliminated rubella and endemic rubella transmission has not been re-established in any country to date. In 2023, 84 countries and areas were verified to have sustained elimination of measles. However, without a global target, this success will be difficult to sustain. Now is the time for a global eradication goal and commitment by the World Health Assembly. Having a galvanising goal, with a shared call for action, will demand adequate resourcing from every country government and global partners. Greater coordination across countries and regions will be necessary. Measles, rubella and congenital rubella syndrome eradication should not remain just a technically feasible possibility but rather be completed to ensure that future generations of children do not live under the shadow of preventable childhood death and lifelong disability. Full article

Influenza viruses can cause highly infectious respiratory diseases, posing noteworthy epidemic and pandemic threats. Vaccination is the most cost-effective intervention to prevent influenza and its complications. However, reliance on embryonic chicken eggs for commercial influenza vaccine production presents potential risks, including reductions in efficacy due to HA gene mutations and supply delays due to scalability challenges. Thus, alternative platforms are needed urgently to replace egg-based methods and efficiently meet the increasing demand for vaccines. In this study, we employed a baculovirus expression vector system to engineer HA, NA, and M1 genes from seasonal influenza strains A/H1N1, A/H3N2, B/Yamagata, and B/Victoria, generating virus-like particle (VLP) vaccine antigens, H1N1-VLP, H3N2-VLP, Yamagata-VLP, and Victoria-VLP. We then assessed their functional and antigenic characteristics, including hemagglutination assay, protein composition, morphology, stability, and immunogenicity. We found that recombinant VLPs displayed functional activity, resembling influenza virions in morphology and size while maintaining structural integrity. Comparative immunogenicity assessments in mice showed that our quadrivalent VLPs were consistent in inducing hemagglutination inhibition and neutralizing antibody titers against homologous viruses compared to both commercial recombinant HA and egg-based vaccines (Vaxigrip). The findings highlight insect cell-based VLP vaccines as promising candidates for quadrivalent seasonal influenza vaccines. Further studies are worth conducting. Full article

During health emergencies, non-pharmaceutical interventions (NPIs) are adopted in various combinations until a vaccine can be produced and widely administered. Containment strategies, including the closure of schools, churches, and dance halls; banning of mass gatherings; mandatory mask wearing; isolation; and disinfection/hygiene measures, require reasonable compliance to be successfully implemented. But what are the most effective measures? To date, few systematic studies have been conducted on the effects of various interventions used in past epidemics/pandemics. Important contributions to our understanding of these questions can be obtained by investigating the historical data from the great influenza pandemic of 1918, an event widely considered one of the greatest natural disasters in human history. Taking on particular importance is the study of the possible role played by the behaviour of the population and the lack of public obedience to the non-pharmaceutical interventions in a Mediterranean country like Italy—one of the most affected countries in Europe—during that pandemic, with special attention paid to the weight of the socio-cultural factors which hindered the ultimate goal of containing the spread of the virus and preventing excess deaths in the country. Full article

Poultry diseases pose major constraints on smallholder production in Africa, causing high flock mortality and economic hardship. Infectious diseases, especially viral diseases like Newcastle disease and highly pathogenic avian influenza (HPAI) and bacterial diseases, especially colibacillosis and salmonellosis, are responsible for most chicken losses, with downstream effects on human nutrition and health. Beyond production impacts, poultry diseases directly harm public health if zoonotic, can give rise to epidemics and pandemics, and facilitate antimicrobial resistance through treatment attempts. HPAI, campylobacteriosis, and salmonellosis are the priority zoonoses. Sustainable solutions for poultry health remain elusive despite recognition of the problem. This review summarises current knowledge on major poultry diseases in smallholder systems, their impacts, and options for prevention and control. We find biosecurity, vaccination, good husbandry, and disease-resistant breeds can reduce disease burden, but practical limitations exist in implementing these measures across smallholder systems. Treatment is often inefficient for viral diseases, and treatment for bacterial diseases risks antimicrobial resistance. Ethnoveterinary practices offer accessible alternatives but require more rigorous evaluation. Multisectoral collaboration and policies that reach smallholder poultry keepers are essential to alleviate disease constraints. Successful control will improve livelihoods, nutrition, and gender equity for millions of rural families. This review concludes that sustainable, scalable solutions for smallholder poultry disease control remain a critical unmet need in Africa. Full article