Search Results (370)

Nipah virus (NiV) is an animal-borne RNA virus of the genus Henipavirus that poses a significant global health threat. This threat is driven by the virus’s high mortality rate, its capacity to cause epidemics, and the lack of licensed therapeutic interventions or vaccines. Since its initial identification during the 1998–1999 outbreak in Malaysia and Singapore, recurrent episodes have occurred primarily in Bangladesh and India, with mortality rates frequently exceeding 70%. Fruit bats of the genus Pteropus serve as the biological host for the virus. Transmission to humans occurs via contact with infected wildlife, consumption of contaminated products, such as freshly harvested date palm sap, or direct person-to-person exposure. Other modes of transmission, such as transplacentally or via breast milk, are still under investigation. The clinical presentation of NiV infection varies widely, from mild flu-like symptoms to life-threatening respiratory disease and acute encephalitis. It frequently attacks the nervous system, which can lead to coma, permanent neurological damage, or relapsing encephalitis. The virus enters host cells via ephrin-B2/B3 receptors, enabling systemic dissemination and infiltration of the central nervous system. Diagnosis relies primarily on RT-PCR and serological assays, and virus isolation requires high-containment laboratories. Management remains largely supportive, as no approved antiviral therapy exists. Experimental agents, such as remdesivir, favipiravir, and monoclonal antibodies such as m102.4, have shown promise in preclinical studies. Multiple vaccine platforms—including subunit, viral vector, mRNA, and nanoparticle-based approaches—are under development, though none is yet licensed for human use. Strengthened surveillance, infection control measures, and continued research are essential to mitigate the threat posed by this emerging pathogen. This review summarizes current knowledge on NiV, including its virology, epidemiology, pathogenesis, transmission, and recent progress in therapeutic and vaccine development. Full article

Brucellosis remains one of the most widespread zoonotic infections worldwide, causing serious veterinary, medical, and socio-economic consequences. The disease, caused by bacteria of the genus Brucella, affects a wide range of domestic and wild animals as well as humans, with global incidence potentially reaching 1.6–2.1 million new cases annually. The most effective approach to combating brucellosis is specific prevention through vaccination. Therefore, we conducted this review to summarize data from existing studies on modern strategies for brucellosis vaccination, types of vaccine platforms, their efficacy, safety, and applicability in veterinary and human medicine. We searched databases including PubMed, Scopus, and Web of Science to identify relevant scientific articles in English published from 1990 to 2025. The aim of this work is to conduct a systematic analysis of modern brucellosis vaccination strategies in livestock and humans, as well as to evaluate the prospects of new vaccine platforms. The review examines live attenuated, inactivated, subunit, vector, and DNA vaccines, as well as their immunological mechanisms of action, advantages, and limitations of application. This information allows for a better understanding of the mechanisms of protective immunity formation and challenges related to DIVA diagnostics (Differentiating Infected from Vaccinated Animals). The “One Health” concept demonstrated the interconnection between human, animal, and environmental factors, emphasizing the need for an interdisciplinary approach to brucellosis monitoring, prevention, and control. Vector vaccines based on influenza virus (Flu-BA), developed in Kazakhstan, have shown high promise, combining immunogenicity, protective efficacy, and a favorable safety profile. Promising directions remain mRNA vaccines, nanoparticles, CRISPR/Cas9 technologies, and mucosal vaccines. Full article

Respiratory syncytial virus (RSV) imposes a substantial burden of severe acute respiratory infection (SARI), especially in young children and the elderly. Methods: We describe RSV epidemiology among hospitalized SARI patients at the Ibn Sina University Hospital Center (Rabat, Morocco) from 1 January 2021, to 31 December 2025, using multiplex PCR (BioFire^® RP2.1plus or Xpert^® SARS-CoV-2/Flu/RSV). Results: Among 4604SARI samples, RSV prevalence was 16.1% (739/4604), predominantly pediatric (88.6%, p < 0.001), with peak burden in infants <6 months (70.4% of cases, p < 0.001). Pediatric prevalence was 28.3% (655/2316) vs. 3.8% (84/2204) in adults (p < 0.001), with predominance in the elderly ≥60 years (51/1041, 4.9%). Co-infections occurred in 46.7% (310/665) of FilmArray-tested positives (total = 665), led by rhinovirus/enterovirus (198/310, 63.9%), and were significantly higher in children (48.5%, p < 0.001). RSV peaked in winter (51.6%), except for summer dominance in 2021 (52.5%), reflecting COVID-19 non-pharmaceutical intervention effects. Conclusions: These data establish Morocco’s first comprehensive RSV surveillance baseline, highlighting post-pandemic epidemiological shifts. As maternal vaccines and monoclonal antibodies emerge, these data inform optimal implementation in low- and middle-income countries (LMICs). Full article

Background/Objectives: Influenza remains a primary cause of severe illness and death in adults over 60. In this group, immunosenescence and existing health conditions make infections more dangerous and traditional vaccines less effective. The MF59-adjuvanted vaccine was specifically designed to overcome these limitations by enhancing the body’s immune activation and antigen presentation. While the vaccine shows clear benefits, some recent concerns regarding vaccine safety have been raised without supporting scientific evidence. Therefore, this systematic review focuses on providing a comprehensive evaluation of its safety outcomes compared to standard vaccines. Methods: Following the PRISMA guidelines, a systematic review and meta-analysis were conducted; two researchers independently assessed the eligibility of the studies, and the risk of bias was assessed using RoB2 and ROBINS tools for randomized clinical trials and observational studies, respectively. Pooled risk estimates were calculated using a random-effects model. Results: Ten RCTs and three non-RCTs meeting the inclusion criteria were included. No significant differences were found for severe systemic outcomes: Guillain–Barré syndrome (RR 1.01, 95% CI 0.64–1.80) and encephalitis (RR 1.23, 95% CI 0.85–1.78). For other systemic adverse effects, there were no significant differences between adjuvanted and non-adjuvanted vaccines; only myalgia showed a small but significant increase with adjuvanted vaccines (RR 1.35, 95% CI 1.02–1.78) compared with non-adjuvanted vaccines. Conclusions: MF59-adjuvanted influenza vaccines have a favorable and well-characterized safety profile in adults aged 60 years and older. Adverse events are predominantly mild and transient, with no evidence of increased risk of serious or immune-mediated outcomes compared with non-adjuvanted vaccines. Full article

Background: During the flu season, there is an increase in absenteeism due to illness, a drop in productivity, and a greater risk of the virus spreading among workers. Thus, the Italian Ministry of Health recommends vaccination for essential service workers. The University of Salerno, in collaboration with the local health authority of Salerno, offers free vaccination to its employees. Methods: A public health methodology for seasonal influenza vaccination in the workplace is presented—specifically in the university setting—with the aim of identifying individual, contextual, and organizational elements of the model that have promoted vaccination uptake. An ad hoc questionnaire was used (October–December 2025) to survey 399 academic employees, investigating seasonal influenza vaccination in the following aspects: recent personal experiences, motivations, vaccination experiences at university, sources of information, considerations regarding national and local vaccination campaigns, and level of vaccine confidence (VCI). Results: Seasonal influenza vaccination at the University is appreciated for its compatibility with working hours (66.1%), the availability of a platform that allows flexible booking (56.9%), the perception of safety in the environment (31.6%), the fact that the vaccine is free (17.4%), and the involvement of office/laboratory colleagues (5%). Participants appreciate the model and would apply it to other vaccinations at the University and in other institutional settings. A significant relationship (F = 7.24; df = 1; p < 0.05) exists between confidence in the vaccine and the sense of security experienced when receiving the vaccine in the workplace. Data analysis was performed using the IBM SPSS v.28 software. Conclusions: The model proposed can be applied to other institutional contexts, simplifying and facilitating access to vaccines by implementing vaccination campaigns tailored to specific work environments. Full article

Background/Objectives: Diabetes is associated with an increased risk of influenza-related complications; therefore, annual vaccination constitutes an essential preventive measure. The objective of this study is to analyze the evolution of influenza vaccination coverage among the population with diabetes in Spain between 2020 and 2023 and to identify factors associated with adherence, comparing it with a matched population without diabetes. Methods: A cross-sectional study was conducted using data from the European Health Survey in Spain 2020 and the Spanish National Health Survey 2023, applying 1:1 matching by age, gender, and place of residence. Multivariable logistic regression was applied to assess time trend and to identify adherence predictors. Results: Vaccination coverage among individuals with diabetes increased from 52.0% in 2020 to 65.9% in 2023 and was higher than that observed among the matched participants without diabetes in both periods. Older age and the presence of comorbidities, such as myocardial infarction or respiratory diseases, were associated with a higher likelihood of vaccination, whereas alcohol consumption and smoking were associated with lower adherence among subjects with diabetes. The year 2023 was independently associated with a higher probability of vaccination compared with 2020 (OR: 1.82; 95% CI: 1.56–2.12). Conclusions: Although influenza vaccination coverage among the Spanish people with diabetes has improved following the COVID-19 pandemic, it remains below recommended targets, highlighting the need to strengthen targeted strategies aimed at less adherent subgroups. Full article

Background: Nursing homes are congregate settings for elderly individuals where infectious diseases can easily spread. The elderly are at high risk of contracting and dying from influenza, and the most effective way to prevent this is to receive the influenza vaccine. Methods: This study conducted a cross-sectional survey of elderly people in nursing homes to investigate the occurrence of influenza symptoms during the 2024–2025 flu season, as well as vaccination status and reasons for receiving or not receiving the vaccine. Bivariate logistic regression was used to determine the factors influencing the vaccination rate. Results: Of the 1024 elderly people who participated in the survey, 25.39% reported experiencing flu-related symptoms in the previous flu season. While 16.21% of the elderly expressed willingness to receive vaccination, only 5.57% actually received it. Influenza vaccination was positively correlated with educational attainment (aOR 3.800, 95% CI 1.480–9.758 for middle school; aOR 5.138, 95% CI 1.738–15.191 for high school), monthly household income (aOR 0.216, 95% CI 0.072–0.644 for >8000), ability for self-care (aOR 0.269, 95% CI 0.123–0.591), and the scale of the nursing home (aOR 9.033, 95% CI 1.531–53.305 for 151–299; aOR 2.629, 95% CI 1.359–5.084 for ≥300). Willingness to receive the influenza vaccination was positively correlated with an unhealthy health status (aOR 0.398, 95% CI 0.204–0.779), symptoms of influenza (aOR 2.730, 95% CI 1.861–4.007), nursing home location (aOR 1.537, 95% CI 1.099–2.941 for outer suburbs), and the scale of the nursing home (aOR 1.991, 95% CI 1.154–3.435 for 151–299; aOR 2.158, 95% CI 1.374–3.390 for ≥300). Most elderly people who received the vaccine believed that vaccination could effectively prevent flu and that it could reduce the risk of complications, the rest were not vaccinated due to concerns about adverse reactions, mobility issues, or the distance to vaccination sites. Conclusions: Low awareness of flu vaccines and physical inability to travel to vaccination sites may be potential barriers to receiving the flu vaccine. It is worrying that the influenza vaccination rate is low among the elderly in nursing homes in Shanghai. As a result, it is crucial to prioritize targeted monitoring and intervention strategies for vulnerable populations living in collective institutions. Full article

The ongoing panzootic of the highly pathogenic avian influenza (HPAI) H5N1 virus, dominated by clade 2.3.4.4b, constitutes a significant global threat to wildlife, animal health, and public health. Once characterized by sporadic outbreaks, H5N1 has evolved into a sustained, year-round infection with an expanded host range that now includes numerous mammalian species. Its high pathogenicity is primarily driven by the acquisition of a polybasic haemagglutinin cleavage site, enabling systemic viral spread, alongside emerging endothelial and neurotropic properties that contribute to severe disease and high mortality in mammals. Although zoonotic transmission remains limited, H5N1 continues to accumulate mutations associated with mammalian adaptation, particularly within the haemagglutinin and polymerase complex. Notably, recent outbreaks in U.S. dairy cattle highlight the emergence of novel mammalian reservoirs with increased human exposure risk. Concurrently, vaccination strategies are advancing beyond traditional adjuvanted inactivated vaccines toward next-generation platforms, including mRNA and virus-like particle vaccines, designed for rapid deployment and broader immune protection. However, ongoing viral evolution, constrained vaccine availability, and gaps in coordinated surveillance underscore the urgent need for an integrated One Health approach to reduce panzootic risk. Full article

Although pharmacist-led vaccination is a global standard for expanding immunization coverage, its adoption in Romania remains at an early stage. While previous studies have focused on early adopters, this research evaluates barriers, perceptions, and readiness among community pharmacies that do not yet provide this service, thereby addressing a critical knowledge gap regarding the “non-vaccinating” majority. A cross-sectional mixed-methods study was conducted among 208 pharmacists representing national chains, regional networks, and independent pharmacies. Quantitative data were analyzed using Chi-square tests and Spearman correlations to identify structural disparities, while a thematic analysis was employed to explore qualitative insights related to professional identity and operational barriers. We identified a clear mismatch between pharmacies’ willingness to provide vaccination services and their practical ability to implement them. Independent pharmacies demonstrated a strong intention to adopt vaccination services (71.4%) but were limited by financial constraints, with high implementation costs identified as a significant barrier (p = 0.014). In contrast, national pharmacy chains had sufficient resources yet faced marked staff resistance, with 43.9% reporting extreme reluctance (p = 0.038). These chains were concentrated in the capital region (p = 0.002), thereby positioning other pharmacies as key providers in underserved areas. Furthermore, thematic analysis revealed a deep-seated “professional identity” crisis, in which pharmacists struggle with the transition from medication specialists to clinical practitioners. The expansion of vaccination services cannot rely on a “one-size-fits-all” strategy. Successful national implementation requires a segmented policy approach, including financial subsidies to support independent pharmacies, change management strategies to engage the corporate workforce, and targeted regulatory education for regional networks to prevent vaccination deserts. Full article

Influenza (flu) is a common respiratory virus with seasonal global spread. Zoonotic viruses can occasionally cross species, leading to pandemic-level spread, and for flu viruses, this is considered an “antigenic shift”. The flu can be particularly severe during pregnancy due to immune system adaptations that occur during pregnancy, with prior global pandemics causing excess hospitalizations, deaths, and other complications in the mothers and the neonates. We aim to review the current literature with respect to novel avian H5N1 and the potential impact of infection with flu during pregnancy. A systematic literature search was conducted. Here we provide a rapid summary of epidemiology and understanding of viral spread, published risks of H5N1 in pregnancy, the unique physiologic, cellular, and molecular adaptations making H5N1 infection unique in pregnancy, implementation of an effective vaccine program in event of a pandemic specific to pregnant individuals, optimizing peripartum care for infected individuals, and direction for future research to direct vaccine strategy and mitigate risks in a future flu pandemic. Full article

Background: Patients with inflammatory rheumatic diseases (IRD) are susceptible to influenza infections and their complications. However, they may avoid vaccination for fear of exacerbating their IRD. This study evaluates the 2023/24 influenza vaccine in IRD patients, aiming to provide recommendations for this group in the upcoming season. Methods: In this prospective, longitudinal study, we assessed the self-reported impact of influenza vaccination on patients with IRD. Participants were recruited nationwide between October and December 2023 and completed an online questionnaire after vaccination as well as at three and six months of follow-up. Results: Among 633 patients, 87.5% were female, with a median age of 50.4 (18–84) years. Post-vaccination, 50% experienced injection site pain; 41% reported no side effects. IRD flares occurred in 5%, with 1% requiring changes to immunomodulation. Among 428 patients with follow-up, influenza infections were reported in 38 patients (8.9%), including 10 (2.3%) with reinfections. No severe cases requiring hospitalization were reported. Spondyloarthritis patients had higher susceptibility to influenza (p = 0.002), accounting for 55.3% of infections. IRD flare-ups in the 12 months before vaccination predicted infections (p = 0.002). Conclusions: The 2023/24 vaccine was well tolerated by IRD patients, with no impact on the course of the disease in 95% of cases. Only 9% of patients reported influenza infections, none of which were severe. In light of these findings, physicians are advised to recommend vaccination to eligible IRD patients prior to or in the respective season. Full article

Background: Seasonal influenza remains a significant public health problem, and the constant antigenic drift of viruses requires regular vaccine updates. mRNA vaccines offer a promising platform for the development of new, effective influenza vaccines. Administration of the naked mRNA vaccine using a needle-free jet injection system further enhances its safety, reduces cost, and eliminates the need for lipid nanoparticles, which are traditionally used for mRNA delivery. Lyophilization of naked mRNA allows for long-term storage at +4 °C. Methods: We designed and produced an mRNA vaccine against seasonal influenza, designated mRNA-Vector-Flu, encoding the hemagglutinin (HA) of the A/Wisconsin/67/2022(H1N1)pdm09, A/Darwin/9/2021(H3N2), and B/Austria/1359417/2021 strains. The vaccine was lyophilized and stored for 1 month in a refrigerator (+4 °C). A comparative immunogenicity study was conducted between synthesized immediately before use prepared and lyophilized naked mRNA-Vector-Flu. The preparations were administered to BALB/c mice using a jet needleless injection twice, 3 weeks apart. Immunogenicity was assessed on day 35 of the study. Results: A comparative immunogenicity study of naked mRNA-Vector-Flu demonstrated that both the synthesized immediately before use prepared formulation and the lyophilized form, stored at +4 °C for a month, induced similar levels of virus-specific antibodies and generated a pronounced T-cell immune response. Conclusions: Delivery of the naked mRNA vaccine using a needle-free jet injection ensures a high-level immune response, which improves its safety, reduces its cost, and eliminates the need for lipid nanoparticles traditionally used for mRNA delivery. At the same time, lyophilization of the naked mRNA vaccine preserves its biological activity and ensures its storage for at least a month at +4 °C temperatures. Our results demonstrate that our proposed approach can be considered a promising direction for the development and improvement of the mRNA vaccine platform. Full article

Background/Objectives: The current strategy for seasonal influenza prophylaxis relies on updating the vaccine components annually to account for the rapid antigenic drift of viruses and the low cross-protective efficacy of available vaccines. Mutant influenza viruses with truncated or deleted NS1 protein are known to stimulate cross-specific T-cell immune response and provide protection against heterosubtypic influenza A and B viruses. Methods: We generated NS1ΔC influenza A and B viruses with C-terminal NS1 deletions by reverse genetics. In a mouse model, we assessed the safety and immunogenicity of the B/Lee/NS1ΔC strain upon intranasal administration, as well as the mechanism of its cross-protective efficacy against sublethal B/Victoria and B/Yamagata challenges. We then investigated the potential of the intranasal Flu/NS1ΔC vaccine–a trivalent formulation of NS1ΔC A/H1N1, A/H3N2, and B influenza viruses–to protect mice from lethal influenza infection with homologous, heterologous, and antigenically drifted influenza A and B viruses. Results: Intranasal immunization with the B/Lee/NS1ΔC strain was safe in mice. It activated cross-specific T-cell responses in the lungs and protected animals against heterologous challenge by reducing viral load, inflammation, and lung pathology. Immunization with the trivalent Flu/NS1ΔC vaccine formulation improved survival and reduced weight loss and viral load upon challenge with A/H1N1pdm, A/H2N2, A/H5N1, and B/Victoria viruses. Conclusions: The trivalent intranasal Flu/NS1ΔC influenza vaccine is a promising tool to improve seasonal influenza protection and preparedness for an influenza pandemic. Full article

Vaccination is the primary method of preventing influenza. During the 2023–24 season, the influenza vaccination for all children between 6 and 59 months was introduced for the first time in Spain. To assess the coverage and adherence of influenza vaccination in childhood during the first two seasons of a vaccination program, as well as to identify the factors associated with influenza vaccination in all children under 5 years of age and those from 5 to 14 years of age with risk factors. Retrospective observational study. All children eligible for the flu vaccine in Central Catalonia during the 2023–24 and 2024–25 seasons were included. A total of 39,937 children were studied. Of these, 79.1% had not been vaccinated for influenza in either of the seasons studied. Influenza vaccination coverage in childhood was 18.1% and 19.3% in the 2023–24 and 2024–25 seasons, respectively. In the 6- to 59-month age range, coverage was 19.1% and 28.9% in the 2023–24 and 2024–25 seasons, respectively. The adherence to vaccination in both seasons was 17%. Some variables (being a non-native person, living in an urban area, having more than one risk factor, or certain underlying conditions) were associated with the influenza vaccination. Coverage and adherence to influenza vaccination in childhood are very low, despite the implementation of a routine influenza vaccination program. Full article

Background: The global incidence of dengue has markedly increased over the last decades. Consequently, the risk of infection has increased significantly, resulting in record numbers of imported cases in various European countries and elsewhere in 2024. Methods: In early 2023, TAK-003, a novel, live attenuated vaccine against dengue, became available in Germany. At the Berlin Centre for Travel & Tropical Medicine, we delivered 56,459 doses during the first 24 months of its availability, from February 2023 to February 2025. To obtain data on the tolerability of the vaccine in travelers, an active follow-up survey was initiated. Results: In total, 30,306 (53.7%) vaccinees agreed to being contacted. Of these, 11,827 (39.0%) completed an anonymous questionnaire ≥ 4 weeks after the vaccination. Overall, 6856 (58.0%) were female, and 565 (4.8%) reported having had a prior dengue infection. The average age was 38.3 years (range 4–86 years). An endemic area had been visited by 6309 subjects before answering the questionnaire, and among these, 46 (0.7%) reported a dengue infection while abroad. All cases were mild, and no complications were reported. TAK-003 was applied with other vaccines in 7363 (62.3%) travelers. Local adverse reactions, mostly local pain, were reported by 5263 (47.5%) subjects. Systemic reactions were reported by 4891 subjects (41.4%) and were most frequently fatigue, myalgia, and flu-like symptoms. The majority of adverse events manifested in the second week after vaccination (median 8 days) and were mostly limited to a duration of 1–3 days. A macular exanthema was described by 1844 subjects (15.6%), typically during the second week after the vaccination. Conclusions: Side effects were frequently reported but generally well tolerated. Age groups above 50 years showed a decline in reactogenicity. Co-vaccination was frequent and led to an increase in systemic adverse events. Denominator data of the study population suggest a strong reporting bias towards adverse events. This survey adds evidence of the chronology and characteristics of adverse events associated with TAK-003 and may support decision making when vaccinating dengue-naïve travelers. Full article