Search Results (2,083)

Introduction: While influenza-associated encephalopathy (IAE) in children remains a serious concern, recent evidence suggests a shift in its epidemiology, with a possible decline in incidence and severity over time. Methods: This retrospective review includes patients aged 0–18 admitted to a tertiary hospital in Northern Italy between November 2023 and February 2025. Inclusion criteria were a positive influenza test, influenza-like symptoms, and neurological involvement. Findings are interpreted alongside current literature. Results: Twenty-five unvaccinated children met criteria for IAE (11 in 2023/24; 14 in 2024/25). Neurological comorbidities were present in 40%. All patients had pathological EEGs. Lumbar puncture was performed in 40%, with abnormalities in 33%. Brain imaging was conducted in 56% of cases, revealing findings in 15%. All received oseltamivir; 60% were also treated with dexamethasone. Severe complications occurred in 16%, while 12% had persistent symptoms or required therapy at discharge. After adjusting for seasonal peak timing, no significant inter-seasonal difference was observed. Discussion: Although IAE continues to present serious risks, recent trends suggest a changing burden. The lack of vaccination among cases underscores the need for prevention. Study limitations include its single-center design and the absence of long-term follow-up. Broader prospective studies are needed. Full article

Background: Self-administered orally dissolving films (ODFs) encapsulating inactivated influenza vaccines represent an effective strategy for stimulating mucosal immunity. While this vaccination method offers several advantages over conventional influenza vaccines, a comparative efficacy study remains lacking. Methods: Female BALB/c mice were immunized with inactivated A/PR/8/34 (H1N1) either via orogastric inoculation or through the oral mucosal delivery using pullulan and trehalose-based ODF vaccines. Each group received equivalent antigen doses across three immunizations. Humoral responses and antibody functionality were assessed using sera collected post-immunization. After lethal viral challenge, other immunological and virological parameters were determined in corresponding tissues. Body weight and survival were monitored over a 14-day period after challenge. Results: ODF vaccination elicited significantly higher virus-specific IgA levels, HAI titers, and neutralizing antibody activity than oral gavage. After the viral challenge, ODF-immunized mice exhibited stronger IgG and IgA responses in respiratory tissues, increased antibody-secreting cells in lungs and spleen, and elevated germinal center B cells and CD8⁺ T cell responses. Both vaccination methods reduced lung pro-inflammatory cytokines and provided full protection against lethal challenge; however, the ODF group showed lower cytokine levels, better weight maintenance, and reduced viral loads. Conclusions: ODF vaccination elicits more robust systemic and mucosal immune responses than oral vaccination and may serve as a promising alternative method of influenza vaccine delivery. Full article

Respiratory viruses can cause life-threatening conditions such as sepsis and acute respiratory distress syndrome. However, vaccines and effective antivirals are available for only a limited number of infections. The majority of approved antivirals are direct-acting agents, which target viral proteins essential for infection. Unfortunately, mutations have already emerged that confer resistance to these antivirals. In addition, there is an urgent need for broad-spectrum antivirals to address the unpredictable emergence of new viruses with pandemic potential. One promising strategy involves modulating the innate immune response and cellular signaling. Imiquimod, a Toll-like receptor 7 (TLR7) agonist, has shown efficacy in murine models of influenza and respiratory syncytial virus (RSV). Additionally, it demonstrates antiviral activity against herpes simplex virus type 1 (HSV-1) and RSV independent of the TLR7/nuclear factor kappa B (NF-κB) pathway, with protein kinase A (PKA) as a crucial downstream effector. In this study, we demonstrate that imiquimod exhibits concentration-dependent antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and canine coronavirus (CCoV) in epithelial cells, underscoring its broad-spectrum action against coronaviruses. Moreover, its anti-coronavirus effect appears to be independent of the TLR/NF-κB and PKA/exchange protein directly activated by cyclic adenosine monophosphate (EPAC) pathways and may instead be linked to the activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway. The ability of imiquimod to inhibit coronavirus replication via the MEK/ERK pathway, coupled with its immunomodulatory properties, highlights its potential as a broad-spectrum antiviral. Full article

The SARS-CoV-2 pandemic and the implementation of associated non-pharmaceutical interventions (NPIs) profoundly altered the epidemiology of seasonal influenza viruses. To investigate these changes, we analyzed influenza-like illness samples in Shenzhen, China, across six influenza seasons spanning 2018 to 2024. Influenza activity declined markedly during the SARS-CoV-2 pandemic compared with the pre-pandemic period but returned to or even exceeded pre-pandemic levels in the post-pandemic era. Phylogenetic analysis of hemagglutinin (HA) and neuraminidase (NA) genes from 58 H1N1pdm09, 78 H3N2, and 97 B/Victoria isolates revealed substantial genetic divergence from the WHO-recommended vaccine strains. Notably, key mutations in the HA genes of H1N1pdm09, H3N2, and B/Victoria viruses were concentrated in the receptor-binding site (RBS) and adjacent antigenic sites. Hemagglutination inhibition (HI) assays demonstrated that most circulating viruses remained antigenically matched to their corresponding vaccine strains. However, significant antigenic drift was observed in H3N2 clade 3C.2a1b.1b viruses during the 2018–2019 season and in B/Victoria clade V1A.3a.2 viruses during the 2023–2024 season. These findings highlight the impact of NPIs and pandemic-related disruptions on influenza virus circulation and evolution, providing critical insights for future surveillance and public health preparedness. Full article

Background/Objectives: Eurasian avian-like (EA) H1N1 swine influenza viruses, with their persistent evolution and zoonotic potential, seriously threaten both swine and human health. The objective was to develop an effective vaccine against these viruses. Methods: A cold-adapted, temperature-sensitive live-attenuated influenza vaccine (LAIV) candidate, GX18ca, was developed. It was derived from the wild-type EA H1N1 strain A/swine/Guangxi/18/2011 (GX18) through serial passaging in embryonated eggs at temperatures decreasing from 33 °C to 25 °C. Its characteristics were studied in mice, including attenuation, immune responses (mucosal IgA, serum IgG, IFN-γ+ CD4⁺/CD8⁺ T-cell responses), and protective efficacy against homologous (GX18), heterologous EA H1N1 (LN972), and human 2009/H1N1 (SC1) viruses. Results: GX18ca showed cold-adapted and temperature-sensitive phenotypes. In mice, it was attenuated, with viral titers in the nasal turbinates and lungs reduced 1000–10,000-fold compared to the wild-type strain, and it cleared by day 5 post infection. Intranasal immunization elicited strong cross-reactive immune responses. Mucosal IgA had broad reactivity, and serum IgG titers reached high levels. IFN-γ+ CD4^+/CD8⁺ T-cell responses were detected against all the tested viruses. A single dose of GX18ca fully protected against GX18 and LN972 challenges, and two doses significantly reduced SC1 lung viral loads, preventing mortality and weight loss. Conclusions: GX18ca is a promising LAIV candidate. It can induce broad immunity, addressing the cross-protection gaps against evolving EA H1N1 SIVs and zoonotic H1N1 variants, which is crucial for swine influenza control and pandemic preparedness. Full article

Background: Health departments disseminate health education related to influenza to the public through various media in China. We examined knowledge, attitudes, and practices regarding influenza and the influenza vaccine (KAP-flu) over time among pregnant women (PW) compared to non-PW. Methods: A cross-sectional survey was conducted in Suzhou, China in 2013 and 2023. We included and interviewed PW seeking prenatal care and excluded PW there for non-routine visits. The comparison group was drawn from non-PW seeking physical examinations at the same facilities. Stratified cluster sampling was used to enroll participants from the various levels of prenatal-care facilities. Results: In 2013, we surveyed 1673 PW and 401 non-PW, and in 2023, we surveyed 2195 PW and 1171 non-PW. The proportion of PW who had ever heard of the influenza vaccine showed no significant change, at 56% in 2013 and 57% in 2023; by contrast, there was a significant increase among non-PW (55% to 78%). The proportion of pregnant participants who knew when to get vaccinated dropped from 14% to 12%, in contrast to the increase among non-PW (6% to 20%). The proportion of PW who believed that the influenza vaccine is effective dropped from 91% in 2013 to 76% in 2023, in contrast to the stable value among non-PW (84% to 82%). In 2023, pregnant participants exhibited lower levels of knowledge about both influenza disease and the influenza vaccine, along with less positive attitudes toward the effectiveness and safety of the vaccine. They also showed lower willingness to vaccinate and lower vaccination rates compared to non-pregnant participants. Concerning KAP-flu among PW, less than half recognized that influenza is different from a common cold; fewer than one in five understood the timing and frequency of vaccination or the policy prioritizing PW for influenza vaccination; vaccination coverage remained below 2% over time. Conclusions: PW had concerning gaps in knowledge and attitudes regarding influenza and the influenza vaccine compared to non-PW in Suzhou, China. Specific actions targeting PW, such as initiatives leveraging the maternal and child healthcare system, are warranted to reduce the gaps. Full article

Infectious bronchitis virus (IBV) and low-pathogenic avian influenza virus (LPAIV) H9N2 are commonly identified in poultry, individually or in association with other pathogens. This study monitored 183 broiler farms affected by respiratory diseases across seven regions of Morocco from January 2021 to December 2023. Among these farms, 87.98% were vaccinated against IBV, while 57.92% were against AI H9N2. Abnormally high mortality rates were observed in 44.26% of the farms, with 24.69% of cases attributed to IBV, 50.62% to LPAI H9N2, and 13.58% due to coinfection with both IBV and H9N2. RT-PCR analysis of tissue samples and cloacal and tracheal swabs collected from 183 broiler farms revealed that 33.33% were positive for IBV and 34.97% for H9N2. Coinfection by IBV and H9N2 was detected in 12.57% of cases, peaking at 17% in 2022. Co-infected flocks exhibited severe clinical signs and lesions, such as reduced food consumption, diarrhea, and renal issues. The predominant lesions were in the respiratory tract, affecting 91.26% of infected broilers. Additionally, among the 183 flocks, 50 farms that tested positive for IBV infection were randomly selected from the seven regions of Morocco for further investigation of other respiratory pathogens, including Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), and infectious laryngotracheitis (ILT), using real-time RT-PCR. Detection rates for these pathogens were 26% for MG, 30% for MS, 4% for ILTv (vaccine strain), and 18% for ILTw (wild strain). Detection rates for single, dual, triple, and quadruple infections were 34%, 42%, 18%, and 4%, respectively. The most common dual and triple coinfections were IBV + H9N2 (14%) and IBV + MG + MS (10%). Phylogenetic analysis of the S gene identified two main IBV genotypes, namely, 793B and D181, with the latter being a strain circulating for the first time in Moroccan poultry. This underscores the urgent need to establish surveillance systems to track pathogen circulation and implement strategies to control virus spread, ensuring the protection of animals and public health. Full article

Background: Influenza is an acute viral disease that primarily affects the airways. It is caused by influenza A and B—RNA viruses. The disease is associated with significant morbidity and mortality. The prevention of influenza includes chemoprophylaxis and vaccination, which are the primary preventive measures against influenza infection and should be highly considered by everyone during influenza season. Methods: A systematic literature search was performed in the databases of PubMed, Web of Science, Scopus, and Embase until September 2024. The review was conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Results: Eventually, a total of 20 publications were included in the final analysis of this systematic review. While general awareness of influenza was moderate, detailed understanding of complications and vaccine safety was frequently lacking. Misconceptions—such as fears of fetal harm and confusion between antiviral and antibiotic treatments—were widespread. Vaccine uptake was generally low but strongly correlated with receiving a healthcare provider recommendation. Willingness to vaccinate was higher in settings where participants were educated during the study process, indicating a crucial role of health communication. Discussion: According to the reviewed literature, the reluctance to receive maternal vaccination often stems primarily from fears or concerns about adverse reactions or misconceptions about the vaccine’s effectiveness, as well as the absence of a physician’s recommendation. Misconceptions regarding vaccine safety, limited understanding of influenza severity, and a lack of clear communication from healthcare professionals are key contributors to low vaccination uptake. Importantly, multiple studies confirmed that recommendation by a trusted healthcare provider significantly increases vaccine acceptance. Conclusions: These findings highlight the urgent need for targeted educational strategies, improved antenatal counseling, and systems-level support to ensure that maternal influenza vaccination becomes a standard and trusted component of prenatal care worldwide. Full article

Background/Objectives: Seasonal influenza vaccination is crucial for reducing morbidity, mortality, and healthcare burdens. The 2023/2024 Ligurian vaccination campaign (Italy) utilized an inclusive model involving local health authorities, general practitioners, pediatricians, and pharmacies to enhance accessibility. Our study aimed at focusing on factors influencing vaccine uptake, public attitudes and access to preventive healthcare services. Methods: A cross-sectional survey was conducted among adults (≥18 years) in Ligurian pharmacies visitors during the vaccination campaign. A self-administered structured questionnaire gathered data on demographics, vaccination history, healthcare access, and awareness. Results: The study included 30,499 participants, and the median age with P25–P75 (years) was 62.0 [47.0–74.0]; 54.6% were female. Considering determinants of accepting influenza vaccination, age was identified as a strong independent predictor. Each one-year increase in age was associated with a 3.8% increase in the odds of influenza vaccination (OR 1.03, 95% CI 1.03–1.04, p < 0.001). Compared to individuals who never visited their general practitioners, those who visited “sometimes”, “often”, or “very often” had significantly higher odds of influenza vaccination (OR 1.54, 1.97, and 1.98, respectively; p < 0.001 for all categories). The strongest predictor of influenza vaccination in the 2023/2024 season was having received the influenza vaccine in the previous season (2022/2023) (OR 71.73, 95% CI 65.38–78.78, p < 0.001). Consistent with increasing age predicting higher influenza vaccination uptake, older age was associated with lower odds of refusing the vaccine due to the belief that “getting or transmitting influenza does not matter” or due to “other or unspecified reasons”. In contrast, receipt of the COVID-19 vaccination significantly increased the odds of holding these opinions. Among individuals who cited reasons such as fear of side effects, concerns about vaccine safety, fear of injections, general opposition to vaccines, or doubts about vaccine effectiveness, having received the COVID-19 vaccine was associated with lower odds of citing these as barriers to influenza vaccination. Conclusions: Fear of side effects and perceived unnecessary vaccination are key barriers. Targeted education and the involvement of general practitioners could enhance vaccine acceptance, particularly among hesitant groups. Full article

Emerging RNA viruses pose a critical threat to aquatic animals, leading to significant ecological and economic consequences. Their high mutation rates and genetic adaptability drive rapid evolution, cross-species transmission, and expanding host ranges, complicating disease management. In aquaculture, RNA viruses are responsible for major outbreaks in fish, while DNA viruses predominate in crustaceans. Marine mammals are increasingly affected by morbilliviruses and highly pathogenic avian influenza (HPAI) H5N1, which has caused widespread mortality events in pinniped and cetacean populations, raising concerns about zoonotic spillover. The absence of effective antiviral treatments and the complexity of vaccine development highlight the urgent need for enhanced biosecurity measures. Furthermore, novel vaccine approaches, such as self-assembling protein nanocage platforms, offer promising solutions for RNA virus mitigation. This review provides a comprehensive analysis of the emergence and significance of RNA viruses in aquatic animals over the last two decades, with a particular focus on biosecurity and vaccine development. Full article

Background: Vaccine hesitancy (VH) is a significant public health challenge, especially during the COVID-19 pandemic. Despite extensive research on the psychological and socio-political determinants of VH, its psychophysiological mechanisms remain unexplored. Grounded in the Somatic Marker Hypothesis, this study aims to investigate the neurophysiological and affective processes underlying VH. Methods: Two experiments will assess sensorimotor resonance and affective processes in VH. In the first experiment, motor-evoked potentials (MEPs) will be recorded from the deltoid and extensor carpi radialis muscles while participants view images of people receiving COVID-19 and influenza vaccines, as well as blood injections (Block 1), and images of vial containing the same substances (Block 2). Facial electromyographic (EMG) activity will measure disgust and fear responses. In the second experiment, skin conductance response (SCR) will be recorded during a virtual reality-based fear conditioning and extinction paradigm. Expected Outcomes: We hypothesize that vaccine-hesitant individuals will exhibit altered sensorimotor resonance, higher affective responses to vaccination stimuli, and impaired fear extinction learning. Psychological traits such as disgust sensitivity, paranoia, anxiety, and dogmatism are expected to be associated with VH. Conclusions: By identifying the psychophysiological mechanisms of VH, this study will contribute to developing effective vaccine promotion strategies to address future public health emergencies. Full article

Background/Objectives: The combination of a hemagglutinin antigen (HA)-based inactivated influenza vaccine (IIV; Fluarix^® Tetra; GlaxoSmithKline) with a nucleoprotein (NP)-based vaccine, such as OVX836, should increase the efficacy of influenza vaccines since it leverages two complementary immunological mechanisms: HA antibodies targeting the virus envelope and neutralizing it, and an NP cell-mediated immune (CMI) response destroying infected cells. Methods: This was a randomized, double-blind, Phase 2a study (ClinicalTrials.gov NCT05284799) including three groups of 60 healthy subjects (18–55 years old) receiving either IIV + placebo, IIV + OVX836 (480 µg), or OVX836 + placebo intramuscularly and concomitantly into the same deltoid muscle. The endpoints were reactogenicity, safety, and immunogenicity (hemagglutination inhibition assay [HAI], anti-NP immunoglobulin G [IgG], and NP-specific cell-mediated immunity [CMI]). Results: The co-administration of IIV + OVX836 was safe and well-tolerated. The HAI response was strong and similar in the two IIV groups with no interference of OVX836. The humoral anti-NP IgG and NP-specific CMI responses to OVX836 were strong in the two OVX836 groups, and no major interference of IIV was observed. Conclusions: This study supports further clinical development of OVX836 as a combined IIV/OVX836 seasonal vaccine capable of inducing robust and complementary HAI and CMI NP-specific responses. Full article

Background: Maternal vaccination is a critical primary preventive approach and an integral part of life-course immunization strategy, influencing the infection-associated morbidity and mortality in pregnant women, foetuses, and young infants. Despite clear guidelines for the administration of vaccines against tetanus, diphtheria, pertussis (Tdap), influenza, and COVID-19 during pregnancy, maternal vaccination rates remain suboptimal in Ireland as per the National Immunisation Office of the Health Service Executive (HSE). Aim: This review explores the prevailing status, uptake factors, and maternal immunization-specific vaccine hesitancy in Ireland. Method: A scoping review was conducted, searching nine electronic databases, including the Irish health research repository Lenus. The search strategy utilised a Population–Concept–Context framework (pregnant women—vaccine uptake/hesitancy—Ireland). Key factors identified and categorised according to the 5A framework: access, affordability, awareness, acceptance, and activation. Results: Searches yielded 2457 articles, and 12 eligible studies were included for review. Influencing factors were identified in each of the 5A dimensions, with the majority relating to acceptance and awareness. Positively associated factors included healthcare provider (HCP) recommendation and knowledge of vaccine safety. Potential antenatal barriers were maternal lack of knowledge of vaccine-preventable illness severity, infection risks, and vaccine safety concerns. A pregnant woman’s primary motivation for antenatal immunization was protection of her infant; however, the reluctance of HCPs to prescribe all recommended antenatal vaccines, inadequate immunization-specific discussion during antenatal consultations, and suboptimal knowledge of pregnancy-specific vaccine safety hampered potential positive influences. The Irish national immunization policy was a facilitator of affordability. Activation can be achieved through public health awareness campaigns and interdisciplinary promotion of maternal vaccination uptake. Conclusions: Maternal vaccination uptake in Ireland remains suboptimal, and a coordinated, targeted approach updating HCP recommendations, enhancing maternal awareness, and highlighting vaccine safety in pregnancy would be required to meet the life-course immunization goals recommended by WHO. By adopting a life-course immunization approach for healthy living, with maternal vaccination as the pivotal central point, vaccination programmes could close immunity gaps at various life stages. Full article

This study proposes and examines the dynamics of a susceptible–exposed–infectious–recovered (SEIR) model for the spread of seasonal influenza. The population is categorized into four distinct groups: susceptible (S), exposed (E), infectious (I), and recovered (R) individuals. The symmetric model integrates a bilinear incidence rate alongside a nonlinear recovery rate that depends on the quality of healthcare services. Additionally, it accounts for the impact of fear related to the disease and includes a constant vaccination rate as well as a nonlinear treatment function. The model advances current epidemiological frameworks by simultaneously accounting for these interrelated mechanisms, which are typically studied in isolation. We derive the expression for the basic reproduction number and analyze the essential stability properties of the model. Key analytical results demonstrate that the system exhibits rich dynamic behavior, including backward bifurcation (where stable endemic equilibria persist even when the basic reproduction number is less than one) and Hopf bifurcation. These phenomena emerge from the interplay between fear-induced suppression of transmission, treatment saturation, and healthcare quality. Numerical simulations using Saudi Arabian demographic and epidemiological data quantify how increased fear perception shrinks the bistability region, facilitating eradication. Healthcare capacity improvements, on the other hand, reduce the critical reproduction number threshold while treatment accessibility suppresses infection loads. The model’s practical significance lies in its ability to identify intervention points where small parameter changes yield disproportionate control benefits and evaluate trade-offs between pharmaceutical (vaccination/treatment) and non-pharmaceutical (fear-driven distancing) strategies. This work establishes a versatile framework for public health decision making and the integrated approach offers policymakers a tool to simulate combined intervention scenarios and anticipate nonlinear system responses that simpler models cannot capture. Full article

Vaccination plays a pivotal role in the control and prevention of animal infectious diseases. However, no efficient and safe universal vaccines are currently registered for major pathogens such as influenza A virus, foot-and-mouth disease virus (FMDV), simian immunodeficiency virus (SIV), and small ruminant lentiviruses (SRLV). Here, we review the development of Sendai virus (SeV) vectors as a promising vaccine platform for animal diseases. Recombinant SeV vectors (rSeVv) possess several key features that make them highly suitable for developing vaccination strategies: (1) SeV has exclusively cytoplasmic replication cycle, therefore incapable of transforming host cells by integrating into the cellular genome, (2) rSeVv can accommodate large foreign gene/s inserts (~5 kb) with strong but adjustable transgene expression, (3) can be propagated to high titers in both embryonated chicken eggs and mammalian cell lines, (4) exhibits potent infectivity across a broad range of mammalian cells from different animals species, (5) undergo transient replication in the upper and lower respiratory tracts of non-natural hosts, (6) has not been associated with disease in pigs, non-humans primates, and small ruminants, ensuring a favorable safety profile, and (7) induce a robust innate and cellular immune responses. Preclinical and clinical studies using rSeVv-based vaccines against influenza A virus, FMDV, SIV, and SRLV have yielded promising results. Therefore, this review highlights the potential of rSeVv-based vaccine platforms as a valuable strategy for combating animal viruses. Full article