Limited added #benefit of seasonal #influenza #vaccination before #H5 vaccination in mice and #ferrets challenged with #H5N1

 

ABSTRACT

Limited A(H5)-specific vaccine supply is expected early in a potential A(H5N1) pandemic, raising the question of whether licensed seasonal influenza vaccines could enhance protection when administered before A(H5) vaccination. We evaluated this strategy in mouse and ferret models using clade 2.3.4.4b A(H5N1) viruses. Seasonal influenza vaccination induced antibodies to seasonal haemagglutinins but did not induce detectable antibodies against A(H5) and did not consistently enhance A(H5)-directed antibody responses after A(H5) vaccination. In lethal challenge studies, seasonal vaccine priming before A(H5) vaccination was associated with improved outcomes compared with A(H5) vaccination alone in one of three mouse experiments, but this effect was not observed in the other two mouse experiments or in ferrets. These findings suggest that seasonal influenza vaccine priming provides limited added benefit to A(H5) vaccine-mediated protection against A(H5N1) under the conditions tested.

Source: 

Link: https://doi.org/10.1080/22221751.2026.2731495

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Epidemiological #investigation of #Shuni virus #infections in #hospitals in two provinces of South Africa (2019–2021) using molecular and serological surveillance

 

Abstract

Shuni Virus (SHUV) is a reemerging zoonotic orthobunyavirus in the Peribunyaviridae family associated with neurological infections and birth defects in humans and animals in Africa and has emerged in the Middle East in the past 10 years. Limited epidemiological data exist in humans, partially due to a lack of clinical awareness and availability of diagnostic assays to determine the incidence of clinical cases and seroprevalence in the population. The goal of this study was to establish serologic and molecular diagnostic assays for SHUV for hospital-based surveillance and to investigate the clinical epidemiology in humans in South Africa. The incidence of SHUV infections was investigated in patients with acute fever of unknown cause with or without neurological signs (AFDUC/N) during the arbovirus season (January-June, 2019–2021). IgM and IgG ELISAs for SHUV were established using baculovirus-expressed glycoproteins and validated against virus-neutralization tests (VNT) positive sera. Orthobunyavirus quantitative RT-PCR (RT-qPCR) and IgM ELISA were used to identify acute infections, and IgG ELISA to define the seroprevalence in patients and healthy control groups in hospitals in Gauteng and Mpumalanga provinces in South Africa. In total, 3/349 (0.84%) AFDUC/N cases tested positive by RT-qPCR and confirmed as SHUV by sequencing. In total, 22/225 (9.7%) AFDUC/N patients had SHUV neutralising antibodies (VNT), of which 11/22 (50.00%) were IgM positive, with an IgM seropositivity of 4.89% (11/225 (4.89%)). Of the RT-PCR and double IgM + VNT+ patients, 60% presented with seizures and 40% with meningitis, of which 36.36% were children and 63.63% were adults, respectively. In total, 9/112 (8%) of the healthy control group tested positive on the IgG ELISA assay. These findings suggest that SHUV is a missed cause of acute neurological infections in hospitalized children and adults in South Africa and should be investigated in humans in Africa and other regions.

Source: 

Link: https://doi.org/10.1371/journal.pntd.0014738

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First detection of High pathogenicity Avian #Influenza #H5N1 Clade 2.3.4.4b Genotype EA-2024-DI.2.1 in #Egypt associated with migratory wild birds

 

Abstract

High pathogenicity avian influenza (HPAI) H5 clade 2.3.4.4b is the main driver of the ongoing unprecedented global panzootic. The recently emerged HPAI H5N1 clade 2.3.4.4b genotype EA-2024-DI.2.1 has become predominant in Europe, with migratory wild birds, particularly waterfowl, playing a major role in its dissemination. Egypt lies along major Afro-Eurasian migratory flyways, which have historically played an important role in the introduction of emerging H5Nx viruses into the country. In this study, targeted surveillance was conducted on 416 wild birds offered for sale in in live bird markets (LBMs) and roadside trading points in northern Egypt, mainly in Damietta and Port Said. Of these, 118 birds showing mild clinical signs were examined post-mortem and lung and tracheal tissues were collected, while oropharyngeal and cloacal swabs were collected from apparently healthy birds. Avian influenza virus was detected by RT-qPCR in 22 wild birds, all from tissue samples, whereas all swabs from apparently healthy birds were negative. Waterfowl accounted for 16 of the 22 positive birds (72.7%), with Eurasian teal showing the lowest Ct values (21-25). Phylogenetic and whole-genome analyses showed that the sequenced wild-bird viruses clustered within the recently emerged EA-2024-DI.2.1 sub-lineage and were closely related to contemporary European viruses. Compared with the EA-2021-AB genotype currently circulating in Egyptian poultry, the EA-2024-DI.2.1 viruses showed several HA amino acid differences, including A83D, L104M and T195A. These findings provide evidence for the introduction of EA-2024-DI.2.1 into Egypt through migratory wild birds and highlight the importance of continued genomic surveillance at the wild bird domestic poultry interface and antigenic evaluation against vaccines currently used in Egypt.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

the British Council International Science Partnerships Fund (ISPF), UK, grant number 1203757062

the Science, Technology & Innovation Funding Authority (STDF), Egypt., project ID 50185

Source: 

Link: https://doi.org/10.64898/2026.09.12.750890

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A Decade of Chronic #Hepatitis E #Treatment: #Ribavirin Effectiveness, Safety, and the Association of Torque Teno Virus Load With Treatment Outcomes

 

Highlights

    • Ribavirin achieved 81% SVR in immunocompromised patients with chronic HEV.

    • Adverse events occurred in 56% and led to discontinuation in 17%.

    • Ribavirin dose reduction was associated with failure to achieve SVR.

    • Higher baseline HEV RNA levels were associated with non-SVR.

    • Baseline TTV load showed a nonsignificant trend toward higher levels in non-SVR patients.

Abstract

Background

Hepatitis E virus (HEV) affects immunocompromised individuals. Unlike immunocompetent hosts, who rarely develop chronic infection, up to two-thirds of immunocompromised patients progress to chronicity. Ribavirin is the recommended antiviral therapy, yet predictors of sustained virological response (SVR) remain unclear. Torque Teno Virus (TTV), a marker of immunosuppression, has been proposed as a potential predictor of viral clearance.

Objectives

We evaluated ribavirin treatment outcomes and adverse effects in immunocompromised patients with HEV infection, and assessed whether TTV load predicts SVR.

Study Design

A retrospective cohort study was conducted at the University Medical Center Groningen including solid organ transplant recipients (SOTR) and haematology patients treated with ribavirin for HEV infection between 2010 and 2022. Clinical data and stored serum samples were analysed to determine infection duration and TTV load at treatment initiation and after three months. TTV loads in treated patients were compared with TTV loads of transplant recipients who spontaneously cleared HEV.

Results

Fifty-two patients received ribavirin; 27 had confirmed chronic infection. SVR was achieved in 81% of chronic cases. Adverse events occurred in 56%, leading to dose reduction in 25% and discontinuation in 17%. Non-SVR was associated with ribavirin dose reduction, lower mean daily dose, higher baseline HEV RNA, and lower ALT. Baseline TTV load showed a nonsignificant trend toward higher levels in non-SVR patients. TTV loads did not differ between treated patients and spontaneous clearers.

Conclusions

Ribavirin is effective for chronic HEV, but treatment-limiting toxicity is common. Adequate dosing appears critical for achieving SVR. TTV load did not reliably predict treatment outcome, underscoring the need for further research into immunological and virological predictors of response.

Source: 

Link: https://doi.org/10.1016/j.jcv.2026.106003

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Detection of Highly Pathogenic Avian #Influenza #H5N1 Virus in #Cat and #Rats during #Outbreak in Backyard #Poultry, #USA, 2025

 

Abstract

In 2025, highly pathogenic avian influenza A(H5N1) virus was detected in a poultry flock in Illinois, USA. Quantitative reverse transcription PCR, sequencing, and histopathology on cat and rat samples from the farm showed multiple positive tissues and high sequence identity to an avian isolate. Small mammals might contribute to H5N1 transmission.

Source: 

Link: https://doi.org/10.3201/eid3210.260418

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#Host type governs #influenza evolutionary #strategy across reservoir and #spillover hosts

 

Abstract

Despite its high propensity for host switching, the evolutionary mechanisms underlying influenza host adaptation remain unclear. H3Nx influenza viruses are uniquely generalist, with long-term lineages that circulate in avian, human, swine, equine, and canine hosts. Using 13,295 H3Nx sequences, we quantified host-specific adaptive evolution and developed a pipeline to map reassortment events onto trees with measures of statistical uncertainty. We find that while H3Nx viruses in mammals undergo adaptive evolution in HA and NA, viruses in birds experience very little directional selection. Instead, avian lineages exhibit high rates of reassortment, frequently generating novel reassortant lineages that persist transiently and turn over rapidly. 29.8-47.4% of all avian reassortant lineages are purged within the first year of circulation, and reassortment shows no fitness benefit in birds. In contrast, reassorted lineages in swine are more likely to persist long-term, suggesting that reassortment in swine may be broadly beneficial. Segment-specific reassortment patterns were also distinct between avian and mammalian viruses, with NA reassorting more frequently than expected in birds, but less frequently than expected in swine. Reassortment events are enriched between mammalian, but not avian, host switches, suggesting that reassortment may be most beneficial for mediating host switches among mammalian species. Together, our data suggest that host differences drive fundamentally different evolutionary outcomes for influenza viruses, transitioning from reassortment-dominant evolution in their avian reservoir, to varying degrees of adaptation upon establishment in mammals.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Pew Charitable Trusts

Margaret Q. Landenberger Research Foundation

National Institute of Allergy and Infectious Diseases

National Institutes of Health

Department of Health and Human Services

United States Department of Agriculture

Agricultural Research Service

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.09.15.751820v1

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Detection of #Divergent Highly Pathogenic Avian #Influenza #H5N1 Clade 2.3.4.4b Virus, São Paulo, #Brazil, 2025

 

Abstract

In 2025, we detected highly pathogenic avian influenza H5N1 virus in dead waterfowl at Ibirapuera Park, São Paulo, Brazil. Genomic characterization indicated a reassortant virus that emerged from locally circulating low pathogenicity avian influenza viruses and highly pathogenic North American lineages. Our results highlight cross-species transmission risk and underscore the need for enhanced surveillance.

Source: 

Link: https://doi.org/10.3201/eid3210.260723

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Estimated #Transmissibility and #CFR of #Bundibugyo Virus, #Uganda, 2007

 

Abstract

Because the epidemiology of Bundibugyo virus remains unclear, we reanalyzed the first recognized outbreak (Uganda, 2007). Adjusting for case under-ascertainment and the effect of control measures, we estimated the effective reproduction number (1.55, falling to <1 after intervention) and case-fatality rate (31%, declining to 25%). The underascertainment rate was 15%.

Source: 

Link: https://doi.org/10.3201/eid3210.261175

____

Experimental Highly Pathogenic Avian #Influenza #H5N1 Clade 2.3.4.4b Virus #Infection in #Alpacas, 2026

 

Abstract

Highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus continues to spread globally and sporadically transmits from avian reservoirs to mammalian hosts. In May 2024, H5N1 infections in young goats and alpacas in the United States were reported. Nevertheless, the overall susceptibility of camelids to clade 2.3.4.4b virus remains unclear. We conducted a controlled experimental infection study in 6 alpacas, assessing clinical signs, viral shedding, tissue distribution, and serologic responses after intranasal inoculation with HPAI H5N1 genotype B3.13 virus. Observed illness was generally mild; body temperature increased slightly and food intake reduced for up to 3 days postinfection. We detected viral RNA in nasal swab samples and confirmed infectious HPAI H5N1 virus. Immunohistochemistry and RNA in situ hybridization detected virus only in the nasopharyngeal tonsil and nasal conchae at 4 days postinfection. Our findings suggest alpacas are susceptible to productive H5N1 infection, highlighting implications for livestock surveillance and biosecurity in regions with ongoing circulation.

Source: 

Link: https://doi.org/10.3201/eid3210.260491

____

Near real-time data on the #human neutralizing #antibody #landscape to #influenza virus in summer of 2026 shows antigenic advance of #H3N2 subclade K region D mutants and #H1N1 D.3.1.1 Sa mutants

 

Abstract

Human seasonal influenza evolves rapidly, necessitating twice yearly decisions about whether to update the strains in the vaccine. To help inform this decision, we have been using high-throughput sequencing-based neutralization assays to make twice yearly measurements of how recent human sera neutralize current human H3N2 and H1N1 strains. Here we provide the third installment in this series of measurements by reporting 47,851 titers representing neutralization of 148 viral strains by 325 human sera collected between April and August of 2026. Our measurements show that new H3N2 subclade K strains with mutations in antigenic region D and new H1N1 subclade D.3.1.1 strains with mutations in antigenic region Sa (such as G155E) have reduced neutralization by human sera, with notable heterogeneity in the impact of some of these mutations across sera from different individuals. This paper is accompanied by an interactive summary (https://jbloomlab.github.io/flu-seqneut-2026/summary.html) that enables detailed exploration of the results, and all titer data are publicly available for further analysis to aid vaccine antigen selection and studies of viral evolution.

Competing Interest Statement

JDB consults for Pfizer, GSK, Apriori Bio, and Merck. JDB has received stock options in the Vaccine Company. JDB is an inventor on Fred Hutch licensed patents related to techniques to characterize the antigenic effects of viral variation. SEH is a co-inventor on patents that describe the use of nucleoside-modified mRNA as a vaccine platform. SEH reports receiving consulting fees from Sanofi, Pfizer, Lumen, Novavax, and Merck. ALG reports contract testing to UW from Abbott, Cepheid, Novavax, Pfizer, Janssen, Assembly Biosciences, Aicuris, Innovative Molecules, and Hologic, research support from Gilead, personal consulting fees from Arisan Therapeutics, outside of the described work. JAE reports support to her institution from GSK, Pfizer, Moderna, and is a consultant for GSK, Pfizer, Merck, Meissa vaccines, Moderna, and Shionogi. ST reports research funding from Pfizer for a separate study.

Funder Information Declared

National Institute of Allergy and Infectious Diseases, R01AI165821, F30AI186284, 75N93021C00015

Howard Hughes Medical Institute, https://ror.org/006w34k90

Source: 

Link: https://doi.org/10.64898/2026.09.15.751855

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Human #Adenovirus B3–Induced Immune #Thrombocytopenia and #Thrombosis

 

{Extract}

(...)

We report here the case of a previously healthy 12-year-old boy in whom virus-induced immune thrombocytopenia and thrombosis developed approximately 1 week after the onset of respiratory infection symptoms. Immune thrombocytopenia was suspected, and prednisolone therapy (30 mg daily) was started at the referring hospital. 

(...)

Source: 

Link: https://www.nejm.org/doi/full/10.1056/NEJMc2605960?query=TOC

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Increased #receptor #binding and #spike glycosylation, remodeled immune #escape of surging #SARS-CoV-2 subvariant BA.3.2.2/RE.2.2/Cicada

 

Significance

SARS-CoV-2 evolved into distinct phylogenetic clades, generating a series of mutant strains. Notably, variants such as BA.1, BA.2.86, and BA.3.2 deserve special attention as they emerged abruptly at high detection frequencies during specific periods and harbored extensive mutations in the spike protein relative to contemporaneously prevalent strains, often accompanied by unique phenotypic characteristics. In this study, we primarily evaluated the structural and functional features of the BA.3.2.2 S protein, revealing its distinct traits in receptor binding, immune evasion, cross-species transmission, and glycosylation evolution. We observed constrained viral immune escape, as certain antibodies that were nonneutralizing against previously dominant subvariants exhibited neutralizing activity against recently emerged BA.3.2.2. These findings provide mechanistic insights for viral surveillance, vaccines, and therapeutics development.

Abstract

SARS-CoV-2 continues to evolve. The subvariant BA.3.2 (Cicada), a derivative of the Omicron BA.3 subtype first detected in late 2024, harbors multiple spike protein mutations, ORF7 and ORF8 deletions, and has recently evolved sublineages (BA.3.2.1 and BA.3.2.2), rendering it a critical target for epidemiological surveillance. The BA.3.2.2 sublineage, represented by RE.2.2, shows a marked upward trend in late 2025. Using surface plasmon resonance, we found that RE.2.2’s spike (S) protein receptor-binding domain (RBD) exhibits relatively high affinity for human receptor angiotensin-converting enzyme 2, with structural analysis identifying the R493Q reverse mutation as the key determinant. Pseudovirus infection and antibody neutralization assays demonstrated that RE.2.2 exhibited a distinct neutralization profile compared to contemporaneous dominant subvariants. Notably, several antibodies that previously lacked neutralizing activity (e.g., S2K146 and L4.65) to other subvariants regained neutralizing potency against RE.2.2, which was associated with key mutations including G446D. Profiling of RE.2.2 RBD binding to ACE2 orthologs across species showed no significant difference in species tropism from the representative Omicron BA.1. Importantly, RE.2.2 exhibits the newly emerged N-linked glycosylation at spike protein N529 (absent in all other subvariants), a modification potentially associated with immune evasion or spike protein conformational dynamics. In addition, we corroborated the “O-follow-N” glycosylation observation as previously reported, where O-linked glycans preferentially localize near N-glycosylation sites, implying coordinated glycan organization as an extra layer of spike regulation. These findings illuminate the evolutionary characteristics, functional changes, and the constrained virus immune escape of BA.3.2.2 (RE.2.2), providing critical insights into antibody development and variant surveillance.

Source: 

Link: https://doi.org/10.1073/pnas.2614163123

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The First 100 Days of Five #Ebola #Outbreaks — #DRC, #Uganda, and West #Africa, 2007–2026 (MMWR, Sept. 15 '26)

 

Summary

    ° What is already known about this topic?

        § The Democratic Republic of the Congo (DRC) is experiencing its largest and deadliest Ebola disease outbreak, which is also the largest Ebola outbreak caused by Bundibugyo virus and the second largest Ebola outbreak worldwide.

    ° What is added by this report?

        § The 2026 Ebola outbreak resulted in 5,458 confirmed cases and 2,606 deaths in DRC in the first 100 days after initial detection, indicating rapid growth. No previous Ebola outbreak caused >800 cases during the first 100 days.

    ° What are the implications for public health practice?

        § This Ebola outbreak appears to be expanding faster than any previously documented Ebola outbreak, with seven times as many cases 100 days after initial detection than the 2014 Ebola outbreak in West Africa, the largest outbreak worldwide. Urgent implementation of public health interventions to identify cases, trace contacts, and limit transmission are needed to bring the outbreak under control.

Abstract

The first 100 days after identification of an outbreak are important to understanding transmission dynamics, impact of early public health interventions, and trajectory of potential future cases and deaths. A large Ebola disease outbreak in the Democratic Republic of the Congo (DRC), which has become the country’s largest and deadliest, is ongoing. To better understand the current outbreak, this report compared metrics from the first 100 days of this outbreak with those of four past Ebola outbreaks. The historic outbreaks of Ebola disease selected for this comparison include the two largest (the 2014 outbreak in West Africa and a 2018 outbreak in DRC), and the only two previous outbreaks caused by Bundibugyo virus (the 2007 outbreak in Uganda and the 2012 outbreak in DRC). This activity was reviewed by CDC, deemed not research, and conducted consistent with applicable federal law and CDC policy.*

Source: 

Link: http://dx.doi.org/10.15585/mmwr.mm7537e1

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#Nuclear #Conflict in Eastern #Europe: #Climate #disruption and #Radiological fallout

 

Abstract

Geopolitical tensions in Eastern Europe underscore the urgency of addressing the climatic and radiological consequences of a regional nuclear conflict. Using an Earth System Model, we simulate a hypothetical nuclear conflict at the Ukraine-Russia border that releases 5 Teragram (Tg; 5 million tons) of black carbon (BC), the dominant driver of the post-detonation climate response, into the stratosphere. We adopt the 5 Tg BC post-detonation emission scenario because it is a widely modelled scenario for a “limited” regional nuclear conflict (typically India–Pakistan), enabling a direct comparison with prior studies. The extended stratospheric lifetime of BC induces hemispheric climate disruption: the Northern Hemisphere cools by ~1 °C in year-1, with anomalies of −5 °C in Russia and −4 °C in the United States; surface solar radiation declines by ~30 W m−2 over the US; and precipitation decreases by ~40% across mid-latitude croplands. Stratospheric warming alters subtropical and polar jets, displacing the Intertropical Convergence Zone ~2–6° southward, delaying climate recovery by ~6 years. Long-lived radionuclides transported with BC disperse globally, with ~40% depositing in the Southern Hemisphere. These findings underscore the importance of nuclear-risk reduction and provide a robust benchmark for food-security and humanitarian-impact assessments.

Source: 

Link: https://www.nature.com/articles/s44407-026-00064-7

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#Habitat-Mediated #Spillover #Risk of #Andes #Hantavirus in Oligoryzomys longicaudatus: A Mechanistic Eco-Epidemiological Model

 

Abstract

Andes hantavirus (ANDV) is a rodent-borne orthohantavirus associated with hantavirus cardiopulmonary syndrome in southern South America. Its maintenance and spillover risk depend on the ecology of its principal reservoir, Oligoryzomys longicaudatus, and on environmental changes that alter habitat availability, host abundance, and human–rodent interfaces. We developed a mechanistic eco-epidemiological model that couples effective habitat cover to an SIR framework for ANDV transmission in O. longicaudatus. Habitat degradation and compensatory restoration modify rodent carrying capacity, natality, and the force of infection, which depends on infected host load relative to instantaneous ecological capacity. We derived the habitat equilibrium, the basic reproduction number ℛ0, and the time-dependent effective reproduction number ℛ𝑒(𝑡) and evaluated infection-burden and threshold indicators across degradation-restoration scenarios. The  analysis shows that ℛ0 is independent of equilibrium habitat cover because susceptible abundance scales with carrying capacity at the disease-free  equilibrium. In contrast, ℛ𝑒(𝑡), cumulative incidence, and infected load depend on transient habitat-mediated crowding. Restoration increases reservoir abundance and absolute infection burden, whereas degradation can reduce abundance while increasing crowding-driven transmission pressure and prolonging supercritical windows. These results identify ecological conditions under which habitat change may intensify reservoir infection pressure and guide One Health surveillance at human–rodent interfaces.

Source: 

Link: https://www.mdpi.com/1999-4915/18/9/1024

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Co-occurrence #networks from #wetland #bird #surveys predict #H5N1 genetic similarity between wild birds with strong effects of time, space and viral clustering

 

Abstract

The emergence of zoonotic and epizootic diseases has had devastating consequences for human and animal health, including wildlife conservation. Yet, surveillance of multi-host disease systems is particularly challenging due to complex transmission pathways across many species. Social network analysis has been applied to simple transmission systems, but empirical applications to wild, multi-species systems are scarce. Here, we combined high pathogenicity avian influenza (HPAI) viral genomes, a zoonotic virus of pandemic potential, with a large citizen-science database of wild bird co-occurrence to test how multi-species social network structure predicts transmission dynamics. We linked viral genetic distance, 20,103 pairwise comparisons between 214 unique genomes from 172 dyads of 20 host species, to co-occurrence network metrics for those species. Both relative species association and raw co-occurrence frequency predicted lower maximum viral genetic divergence, more similar viruses between more associated species, beyond what would be expected through random mixing and independently of sequencing effort. Time and space between samples were also strong predictors of genetic similarity. Our results suggest that network models can be used to detect pathogen transmission through communities of wild birds, offering real prospects for wildlife disease surveillance and prediction.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.1101/2025.06.17.659947v5

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#Pathogenesis and natural history of the #Bundibugyo species of #Orthoebolavirus in nonhuman #primates

 

Abstract

The current outbreak of Bundibugyo virus (BDBV) in Africa is a global public health concern particularly as there are no licensed medical countermeasures (MCM). Well characterized animal models that accurately replicate human BDBV infection are needed to develop effective MCM. We exposed 21 cynomolgus monkeys (CM) to BDBV to examine the progression and natural history of BDBV disease (BVD). BVD was more protracted than reported for Ebola and Sudan infection in CM with a lower lethality rate of 67% consistent with lower human BVD mortality rates. IHC and spatial proteomics identified CD209+, CD68+, and/or HLA-DR+ macrophages and dendritic cells as early targets of BDBV. These infected cells frequently colocalized with fibrin and infiltrating MPO+ neutrophils and S100A9+ myeloid-derived suppressor cells, consistent with the development of an active inflammatory response and early coagulopathy. Transcriptomic and proteomic analyses of the circulating immune response correspondingly reflected a cytokine-driven hyperinflammatory state in CM that succumbed to disease. Surviving animals resolved systemic inflammation by the study endpoint; however, BDBV antigen was identified in immune privileged tissues with lesion-associated inflammation aligning with known post-Ebola sequela in humans. This data should assist in identifying weaknesses in the disease course that can be exploited to develop new MCM.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

National Institute of Allergy and Infectious Diseases, https://ror.org/043z4tv69, U19AI109945

The University of Texas Medical Branch at Galveston, https://ror.org/016tfm930, N/A

Source: 

Link: https://doi.org/10.64898/2026.08.10.743937

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Assessment of immune #response induced by ChAdOx1 nCoV-19, Sputnik V, and BNT162b2 #vaccines during #COVID19 #outbreak in #Mexican population: Gene expression of the #cytokine storm

 

Highlights

    • The molecular immune response triggered by vaccines against COVID-19 was analyzed.

    • The evaluated genes were ACE2, CD79B, TMPRSS2, CTSB, FCGR3A and MB-1.

    • These vaccines induce a protective immune response through various mechanisms.

    • Vaccines regulate the immune response through pro- and anti-inflammatory cytokines.

Abstract

Introduction

COVID-19 vaccines using different technological platforms may induce distinct molecular responses. Characterizing gene-expression patterns after vaccination and in fatal COVID-19 may identify pathways associated with vaccination and severe disease.

Objective

To compare immune-, inflammatory-, and SARS-CoV-2-entry-related gene expression after AstraZeneca, Pfizer, or Sputnik V vaccination and with unvaccinated fatal COVID-19.

Materials and methods

Eighty Mexican adults were included: AstraZeneca (n = 19), Pfizer (n = 20), Sputnik (n = 21), and unvaccinated fatal COVID-19 (n = 20). Expression of 11 genes was measured by qPCR at days 30 (D30) and 60 (D60) after vaccination.

Statistical analysis

Longitudinal differences were analyzed by two-way repeated-measures ANOVA. Comparisons with fatal COVID-19 were exploratory. Benjamini–Hochberg correction controlled false discovery rate at 5%.

Results

No differences among vaccines were detected at D30. At D60, IL-10, IL-2, and CD79A differed among selected vaccine groups. Longitudinally, FCGR3A decreased in AstraZeneca and Sputnik, ACE2 decreased in Pfizer and Sputnik, and TMPRSS2 increased in Sputnik. Fatal COVID-19 showed predominantly higher expression of several genes than vaccinated groups. Notably, IL-2 and ACE2 were consistently higher in fatal COVID-19 than in all vaccinated groups at both time points.

Discussion and conclusions

Post-vaccination transcriptional profiles were dynamic, with selected differences emerging at D60, whereas fatal COVID-19 exhibited a distinct profile characterized predominantly by higher expression of immune-, inflammatory-, and viral-entry-related genes. Consistent IL-2 and ACE2 differences highlight molecular pathways potentially associated with severe disease. The observational design, however, precludes causal attribution to vaccination.

Perspectives

Longitudinal studies with appropriate controls are needed to establish the biological significance of these transcriptional patterns.

Source: 

Link: https://doi.org/10.1016/j.meegid.2026.106025

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