#Vaccination against #H5 HP #influenza virus leads to persistent immune response in wild king #penguins

 

Abstract

Since 2021, the panzootic of high pathogenicity avian influenza (HPAI) represents an increasing threat to wild vertebrate populations. In this context, recent vaccines developed for poultry could provide tools for the conservation of wild endangered birds populations. The king penguin (Aptenodytes patagonicus), a long-lived seabird breeding in dense colonies with an extended chick-rearing period, was identified as a possible surrogate species for a vaccination trial in a sub-Antarctic natural setting. We investigate here the immune response of king penguin chicks to a self-amplifying mRNA vaccine against a H5 HPAI clade 2.3.4.4b protein. Thirty chicks were vaccinated (primo- and boost-injections), 20 were kept as controls. Along 250 days of monitoring, vaccinated chicks showed a high and persistent immune response, granting a strong seroneutralisation capacity against the virus, up to fledging. No adverse effects were observed. The screening for antibodies against unspecific avian influenza viruses suggested that no natural infection occurred over the entire trial. The emergence of HPAI in the Southern Indian Ocean in October 2024 highlights the timeliness of such experimental tests. Our results show the vaccine could provide a powerful tool for mitigation and emphasises the need for studies considering ethical and practical issues of vaccination for wildlife conservation.

Competing Interest Statement

The authors declare as only conflict of interest that the work was partially funded by Ceva Wildlife Research Fund, an endowment fund created by Ceva Sante Animale, whose objective is to support applied animal health research projects contributing to wildlife conservation. Ceva Wildlife Research Fund had no role in the conceptualization, design, data collection, analysis, decision to publish, or preparation of the manuscript.

Funder Information Declared

French Polar Institute (IPEV), Project ECOPATH-1151, Project ECOENERGY-119

Agence Nationale de la Recherche, https://ror.org/00rbzpz17, ECOPATHS ANR-21-CE35-0016, WILDFLU ANR-2025-CE35-00XX

Ceva Wildlife Research Fund, CWRF2

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.06.674613v1

____

#Transcontinental Spread of HPAI #H5N1 from South #America to #Antarctica via Avian #Vectors

 

Abstract

Our study has for the first time identified H5N1 strains (clade 2.3.4.4b, genotype B3.2) in brown skuas from the Fildes Peninsula, South Shetland Islands, Antarctica. These findings indicate that highly pathogenic avian influenza H5N1 viruses is now actively circulating in Antarctic ecosystems, representing a significant expansion of its geographic range.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

National Key Research and Development Program of China, 2024YFC2813605, 2023YFC2605504

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.06.674605v1

____

Investigating high pathogenicity avian #influenza virus #incursions to remote #islands: Detection of #H5N1 on Gough Island in the South Atlantic Ocean

 

Abstract

Understanding the mechanisms underlying the emergence and spread of high pathogenicity avian influenza virus (HPAIV) is critical for tracking its global dissemination, particularly via migratory seabirds, given their role in transmission over long distances. Scavenging seabirds, such as skuas, may act as both reservoirs and vectors, and have been linked to multiple outbreaks since 2021. Here, we report the detection of HPAIV clade 2.3.4.4b H5N1 in three Tristan skua (Stercorarius antarcticus hamiltoni) carcasses on Gough Island in the central South Atlantic Ocean. To investigate potential incursion routes, we combined genomic analyses with year-round tracking data from global location sensors. Although migratory movement patterns suggested southern Africa as the most obvious pathway, the strain detected on Gough Island was more closely related to that found in South Georgia, suggesting infection may have occurred during the pre-laying exodus when skuas disperse into frontal waters south of the island. No further cases have been confirmed for Gough, but further systematic monitoring is needed to understand the dynamics of virus infection. The detection of HPAIV H5N1 in skuas on Gough Island highlights the importance of continued vigilance, coordinated surveillance, and proactive biosecurity across the South Atlantic and Southern Ocean, alongside efforts to reduce other pressures on globally important seabird populations to help strengthen their resilience.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Department for Environment, Food and Rural Affairs (Defra, UK) and the Devolved Administrations of Scotland and Wales, SV3006, SV3032 and SE2227

Biotechnology and Biological Sciences Research Council (BBSRC) and Department for Environment, Food and Rural Affairs (Defra, UK) research initiative FluTrailMap, BB/Y007271/1

European Union (EU), 101084171

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.06.674618v1

____

#Spain closes several #parks and #attractions due to #birdflu #outbreak (Xinhua)

{Automatic translation from Chinese, edited}

[Xinhua News Agency Micro Special] Due to the outbreak of avian influenza in many places, the Andalusia Autonomous Region in southern Spain has temporarily closed a number of parks and other attractions in recent days, including two attractions included in the UNESCO World Heritage List, and the infected animals have been killed at relevant locations.

According to AFP, Seville City Hall announced on social media on the 11th that the Maria Luisa Park in the city center was closed due to the discovery of dead birds. The park will clean up the dead animals and disinfect them.

The city recently closed three other parks where dead birds were found, including a World Heritage site.

Catalina Garcia, an environmental official for the Andalusian autonomous region, said on social media that three outbreaks of avian influenza were detected in wild birds in Doñana National Park, a World Heritage site, and the affected birds were culled. The national park, located on the right bank of the Guadalquivir River where it meets the Atlantic Ocean, is known for its diverse ecosystems, with more than 500,000 waterfowl wintering there each year.

The Andalusian Autonomous Regional Government issued a statement on the 9th saying that after an outbreak of avian influenza on two farms in Huelva Province, relevant parties are taking measures to prevent the spread of the epidemic and have killed the infected poultry, but did not disclose the specific number.

Europe is currently experiencing a peak season for avian influenza, with outbreaks of the highly pathogenic H5N1 avian influenza reported in countries including the United Kingdom, Germany, and Portugal.

According to the World Organization for Animal Health, migratory birds, particularly waterfowl, are natural reservoirs of avian influenza viruses, contributing to their widespread geographical spread. Avian influenza outbreaks are also a major public health concern. Previous outbreaks of avian influenza in poultry have been linked to sporadic cases of human infection. When an outbreak occurs, the typical response is to cull all affected birds, regardless of infection, to contain the virus. (End) (Qiao Ying)

Source: Xinhua, https://www.163.com/dy/article/K98N72NP05346RC6.html?spss=dy_author

____

#Italy, Integrated #Surveillance for #WNV & #USUV - Weekly Bulletin No. 9, 11 September '25 (summary): 80 new cases

{Summary}

-- During current epidemiological week (4 to 10 September), eighty new confirmed human cases of West Nile Virus infection have been reported in Italy.

-- Since the beginning of the epidemic season, there have been a total of 582 confirmed cases (they were 502 last week), of these: 

- 260 were West Nile Neuroinvasive Disease (WNND): 14 in Piedmont, 24 Lombardy, 22 Veneto, 1 Friuli-Venezia Giulia, 1 Liguria, 20 Emilia-Romagna, 3 Tuscany, 77 Latium, 2 Molise, 74 Campania, 1 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 13 Sardinia, 

- 48 asymptomatic cases among blood donors, 

- 262 cases of West Nile Fever (1 imported from Kenya), 

- 4 asymptomatic cases, 

- 8 unspecified cases. 

-- A total of 39 fatal cases have been reported so far this season: 5 in Piedmont, 2 Lombardy, 1 Emilia-Romagna, 15 Latium, 14 Campania, 2 Calabria. 

- The Case-Fatality Rate among WNND cases is thus far at 15% (during 2018 season it was 20%, in 2024 14%). 

-- During current surveillance week there were 7 new confirmed Usutu Virus infection cases: 2 in Piedmont, 2 Lombardy, 1 Veneto, 2 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_09.pdf

____

First #Evidence of #Mammarenavirus in the Giant Fruit #Bat (Artibeus lituratus) in #Mexico

 

Abstract

Background: 

In Mexico, two Mammarenavirus genotypes have been identified: Real de Catorce virus and Ocozocoautla de Espinosa virus (OCEV), which are found in rodents (Neotoma leucodon and Peromyscus mexicanus). Mammarenaviruses from clade B cause mild to severe infectious diseases in humans, particularly in South America. A 1967 outbreak in Chiapas, Mexico, was potentially linked to the OCEV.

Materials and Methods: 

Between 2017 and 2020, we collected bats across southern/southeastern Mexico to identify Mammarenavirus reservoirs. We analyzed 81 liver samples from 14 bat species using nested PCR. For quality control, we synthesized and OCEV S-region fragment into an ampicillin-resistant pUC57 plasmid, cloned in One Shot Stbl3 chemically competent E. coli.

Results: 

Here, we report the first detection of a Mammarenavirus (OCEV) in an Artibeus lituratus bat from Sabancuy, Campeche, southeastern Mexico. This finding represents the third Mammarenavirus recorded in this bat species in the Americas, suggesting it may harbor multiple Mammarenavirus species (OCEV and Mammarenavirus tacaribeense).

Conclusions: 

While this represents the first documentation of OCEV in a bat, it remains unknown whether environmental stressors could facilitate potential transmission to humans, particularly given the close association between Artibeus bats and human populations.

Source: Vector-Borne and Zoonotic Diseases, https://www.liebertpub.com/doi/abs/10.1177/15303667251377563

____

#Marburg Virus #Disease in #Rwanda, 2024 — Public Health and Clinical Responses

 

Abstract

Background

On September 27, 2024, Rwanda reported an outbreak of Marburg virus disease (MVD), after a cluster of cases of viral hemorrhagic fever was detected at two urban hospitals.

Methods

We report key aspects of the epidemiology, clinical manifestations, and treatment of MVD during this outbreak, as well as the overall response to the outbreak. We performed a retrospective epidemiologic and clinical analysis of data compiled across all pillars of the outbreak response and a case-series analysis to characterize clinical features, disease progression, and outcomes among patients who received supportive care and investigational therapeutic agents.

Results

Among the 6340 patients with suspected MVD who underwent testing, 66 had laboratory-confirmed MVD, 51 (77%) of whom were health care workers. The median estimated incubation period was 10 days (interquartile range, 8 to 13), and symptom onset occurred a median of 2 days (interquartile range, 1 to 3) before hospital admission. The results of epidemiologic investigations were highly suggestive of a zoonotic origin of the outbreak: an index patient was identified who had been exposed to Egyptian fruit bats at a mining site. The case fatality rate in the outbreak was 23% (15 deaths among 66 patients). Remdesivir and the monoclonal antibody MBP091 were used under expanded access and clinical trial protocols. In addition, 1710 frontline workers and high-risk contacts received the chimpanzee adenovirus 3–vectored vaccine ChAd3-MARV under emergency use authorization in a phase 2 clinical trial.

Conclusions

Implementation of containment measures, advanced supportive care, and access to investigational countermeasures may have contributed to reduced mortality from MVD in this outbreak. Enhancing surveillance, improving infection prevention and control in health care settings, and ensuring timely deployment of medical countermeasures will be critical for mitigating the effects of future filovirus disease outbreaks.

Source: The New England Journal of Medicine, https://www.nejm.org/doi/full/10.1056/NEJMoa2415816?query=TOC

____

Public #Health #Situation #Analysis - occupied #Palestinian territory-September (#WHO, Sept. 10 '25)

 

Overview

Starvation and malnutrition in Gaza are at the highest levels ever since the conflict began almost two years ago. 

Deliberate blocking and delay of large-scale food, health, and humanitarian aid has cost many lives.

Malnutrition is on a dangerous trajectory in the Gaza Strip, marked by a spike in deaths in July. 

As of 5 September 2025, 361 Palestinians have died due to malnutrition, including 130 children. 

As of 15 August 2025, Famine (IPC Phase 5)—with reasonable evidence—is confirmed in Gaza Governorate. 

After 22 months of relentless conflict, over half a million people in the Gaza Strip are facing catastrophic conditions characterised by starvation, destitution and death. 

Another 1.07 million people (54%) are in Emergency (IPC Phase 4), and 396 000 people (20%) are in Crisis (IPC Phase 3).

More broadly, since 7 October 2023, as reported by Ministry of Health (MoH), the number of casualties include 63 746 fatalities and 161 245 injuries.7 

As of 5 September 2025, there have been 2 339 reported fatalities among aid seekers near militarized distribution sites and along convoy routes since 27 May.

Ongoing attacks and resource shortages have severely weakened the health system – damaging or destroying 94% of hospitals, overwhelming remaining partially functional ones, and disrupting essential health service delivery. 

The Health Cluster reports that hospitals are overwhelmed by mass casualty incidents, with an average of eight incidents per day. 

Al-Shifa and Al-Ahli hospitals, in Gaza city, are operating at nearly 300% over capacity, with a constant influx of complex trauma injuries. 

Every hospital is overrun. If the Israeli-announced offensive on Gaza city goes ahead, the Gaza Strip could lose half of its hospital bed capacity. 

On 20 July, the WHO’s main warehouse in Deir Al-Balah was destroyed due to attacks, amid MoH reports that 52% of essential drugs and 68% of medical disposables are at zero stock.

In the West Bank, escalating settler violence, with the acquiescence, support, and in some cases participation, of Israeli security forces, has worsened the coercive environment in the occupied West Bank, resulting in several Palestinian casualties and the forcible displacement of Palestinian communities in the last month.

Source: World Health Organization, https://www.who.int/publications/m/item/public-health-situation-analysis---occupied-palestinian-territory-September

____

#Infection of #ratites with clade 2.3.4.4b HPAIV #H5N1: Potential implications for zoonotic #risk

 

Abstract

We detected H5N1 high pathogenicity avian influenza in captive Greater Rhea (Rhea americana). Viral genetic analysis revealed the mammalian associated PB2-E627K mutation, indicating selection of mammalian-relevant mutations in ratites. Pathologic investigation of available tissues demonstrated severe multifocal necrotising inflammation, and a strong vasculotropism.

Competing Interest Statement

The authors have declared no competing interest.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.08.674895v1

____

Divergent #antibody-mediated #population #immunity to #H5, #H7 and #H9 subtype potential #pandemic #influenza viruses

 

Abstract

Influenza continues to cause significant mortality globally and possesses substantial pandemic potential. Assessing pandemic risk requires a clear understanding of existing population immunity. Leveraging a unique large-scale cohort of human sera, we evaluated total and neutralising antibody-mediated immunity to multiple haemagglutinin (HA) proteins, including those from subtypes with high pandemic potential. Our analysis reveals that population immunity is heterogeneous, with distinct age-dependent differences in responses to H5, H7, and H9 avian influenza subtypes. These shifts align with historical circulation patterns of seasonal H1N1 and H3N2 human viruses. Notably, H7 viruses are primarily neutralised through head domain epitopes, while H5 viruses are targeted mainly via stem epitopes, although in both instances some neutralisation occurred via receptor binding site-adjacent epitopes. Furthermore, H7 responses were dominated by non-glycan-targeted IgG2 antibodies, whereas H5 responses were primarily IgG1-mediated. These findings highlight varying levels of susceptibility to influenza across the population, supporting vaccination approaches informed by exposure history.

Competing Interest Statement

CPT has received lecture fees from Moderna.

Funding Statement

J.S.B. was supported by funding from the Biotechnology and Biological Sciences Research Council (BBSRC) doctoral training programme grant [grant number BB/M011224/1]. R.S. is funded by a Medical Research Council Impact Accelerator Account grant [grant ref MR/X502674/1]. RG was funded by The Institute for Global Pandemic Planning at the University of Warwick, UK, as part of a philanthropically supported doctoral programme. K.C. was funded via the Medical Research Council doctoral training programme grant [MC_UP_A025_1011]. L.H. was funded by a Defence and Science Technology Laboratory grant [grant ref RQ31692]. U.O. and C.P.T. acknowledge funding from the British Council ISFP scheme [grant number 47650215]. N.C.R. is supported by a Royal Society Dorothy Hodgkin Research Fellowship [grant number DHR00620].

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.09.08.25335309v1

____

#Norway - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Follow up report 1

 

A poultry farm in Nordland Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6767

____

#China reported four additional #human pediatric cases of #infection with avian #influenza #H9N2 virus (HK CHP, September 9 '25)

{Summary, excerpts}

-- Avian influenza A(H9N2): 

- Anhui Province: 

1) A two-year-old boy with onset on August 5, 2025. 

- Chongqing Municipality: 

2) A six-year-old boy with onset on July 30, 2025. 

- Hunan Province

3) A two-year-old boy with onset on August 21, 2025. 

- Sichuan Province: 

4) A one-year-old boy with onset on July 28, 2025. 

(...)

Source: Centre for Health Protection, Hong Kong PRC SAR, https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk36.pdf

____

#Autoantibodies in #longCOVID: a systematic #review

 

Summary

Post-COVID-19 condition (also known as long COVID) affects a substantial proportion of individuals who have been infected with SARS-CoV-2, profoundly affecting their daily lives and work. Diagnosis and prognosis of long COVID are complex and hindered by heterogeneous symptoms and the absence of validated biomarkers. This systematic review synthesises current evidence on the association between autoantibodies and long COVID, with the goal of evaluating their prognostic and diagnostic utility. Studies published in the PubMed and MEDLINE databases between Jan 1, 2020, and June 10, 2025, were considered. Study selection and quality assessment were done independently by two researchers. Of the 1113 publications screened, 44 studies met the inclusion criteria, with a total of 7571 participants, including 3372 individuals with long COVID. 31 (71%) studies reported an association between autoantibodies and long COVID; however, there was substantial heterogeneity in study design, type and timing of antibody measurements, and long COVID definitions. Several autoantibodies have been associated with long COVID occurrence, symptoms, and severity. Antinuclear antibodies, and autoantibodies targeting G protein-coupled receptors and chemokines, have emerged as potential biomarkers for aiding in the diagnosis, prognosis, and assessment of disease severity in long COVID. However, larger studies are needed to confirm the diagnostic and prognostic utility of these autoantibodies in the context of long COVID.

Source: Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00411-6/abstract?rss=yes

____

Heterologous two-dose #Ebola #vaccine regimen in #pregnant women in #Rwanda: a randomized controlled phase 3 trial

 

Abstract

Risk of death for both mother and fetus following Ebola virus infection is extremely high. In this study, healthy women in Rwanda aged ≥18 years were randomized to two-dose Ebola vaccination (Ad26.ZEBOV, MVA-BN-Filo) during pregnancy (group A) or postpartum (group B). Unvaccinated pregnant group B women served as control. This was a parallel, randomized, controlled, open-label, single-center trial to evaluate the safety (primary endpoint—outcomes of interest and serious adverse events (SAEs)) and immunogenicity (secondary endpoint) of the two-dose Ebola vaccination. Among 3,484 women screened, 2,013 were randomized, and 2,012 women and 1,945 infants born alive were descriptively analyzed. Adverse outcomes of interest occurred in women (5.2% in group A and 7.3% in group B) and infants (26.0% in group A and 25.6% in group B). The most common maternal outcome of interest was pathways to preterm birth (3.2% in group A and 3.4% in group B), and the most common infant outcome of interest was small for gestational age (14.3% in group A and 11.8% in group B). Maternal/fetal and neonatal/infant SAE frequencies were comparable between groups (9.8% in group A, 9.0% in group B and 21.9% in group A, 15.9% in group B, respectively). Anti-Ebola virus glycoprotein-specific binding antibody response (secondary endpoint) was sustained in ≥90% of women at 1 year postdose 1. In group A, binding antibodies were detected in cord blood (99%) and infant serum (95%) samples 14 weeks postbirth. The trial met all primary and secondary objectives. Ad26.ZEBOV, MVA-BN-Filo did not raise concerns regarding adverse maternal/fetal or neonatal/infant outcomes, had no unexpected safety issues, and induced binding antibody responses in women and offspring through passive transfer. ClinicalTrials.gov registration: NCT04556526.

Source: Nature Medicine, https://www.nature.com/articles/s41591-025-03932-z

____

Shared viral burdens: Evidence of active #Usutu virus circulation and multi- #arbovirus exposure in migrant and resident #birds at wintering locations in #Nigeria

 

Abstract

Background: 

West Nile (WNV), Usutu (USUV), and Sindbis (SINV) virus were initially detected in the African region, and subsequently across temperate regions where they were absent. Wild birds are primary reservoirs for these arboviruses and are considered major contributors to their global spread through seasonal migration. To understand the transmission dynamics of arboviruses in wild birds and the potential of migratory birds to spread the viruses at an intercontinental scale, we investigated arboviral infections and exposures in African resident and Palearctic migratory birds at wintering locations in Nigeria. 

Methodology/Principal Findings: 

Oropharyngeal- and cloacal swabs, feathers and blood were collected from resident and migratory birds at two wintering locations (Amurum and Ngel-Nyaki Forest Reserves). Swabs and feathers were tested using RT-PCR for WNV, USUV and SINV, and blood with ELISA and FRNT90 or PRNT80 for antibodies. 573 birds were sampled between 2021 to 2024 across months coinciding with arrival and departure of migratory birds. USUV RNA was detected in 2.6% of feathers including a positive Icterine warbler and a garden warbler sampled prior to spring migration. None of the swabs was positive for viral RNA but neutralizing antibodies to WNV and USUV were detected in 4.5% of birds. SINV antibodies were also found in 34.1% of birds sampled across the wintering locations. 

Conclusions/Significance: 

Our findings showed that migratory birds can become infected with USUV, and potentially with WNV and SINV during their overwintering periods in Africa and highlighted a wider arbovirus risk in Nigeria. In addition, detections of viral RNA in feathers, but not swabs, suggest feathers may be a suitable matrix for surveillance in the absence of a reliable cold chain. The overall detections in wild birds at these locations highlight the need for further surveillance to define the epidemiology and public health risks of these arboviruses in the region.

Competing Interest Statement

The authors have declared no competing interest.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.08.674803v1

____

Continuous #evolution of #Eurasian #avian-like #H1N1 swine #influenza viruses with pdm/09-derived internal #genes enhances #pathogenicity in mice

 

ABSTRACT

Swine influenza A virus (swIAV) is an important zoonotic pathogen with the potential to cause human influenza pandemics. Swine are considered “mixing vessels” for generating novel reassortant influenza A viruses. In 2009, a swine-origin reassortant virus (2009 pandemic H1N1, pdm/09 H1N1) spilled over to humans, causing a global influenza pandemic. This virus soon spread back into swine herds and reassorted with the circulating swIAVs. We previously reported that the genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bore pdm/09- and triple reassortant (TR)-derived internal genes, had been predominant in swine populations of China since 2016, posing a threat to both the swine industry and public health. Here, our ongoing surveillance confirmed that G4 EA H1N1 viruses remained the predominant swIAVs in China from 2019 to 2023 and had reassorted with the co-circulating swIAVs, such as the H3N2 virus, to generate novel reassortant EA H1N2 viruses. Genetic analyses revealed that the pdm/09-derived internal genes of G4 EA H1N1 viruses originated from reassortments between pdm/09 H1N1 and EA H1N1 viruses in 2009–2010 and underwent independent and continuous evolution in the swine host, exhibiting higher evolutionary rates than those of the pdm/09 H1N1 virus circulating in humans. The accelerated evolution of internal genes enhanced the polymerase activity of G4 EA H1N1 viruses in mammalian cells, resulting in increased viral replication and pathogenicity in mice. This study provides evidence for swine in promoting the genetic evolution of influenza A virus and highlights the need for increased attention to novel reassortant viruses in swine.

IMPORTANCE

The emergence of pdm/09 H1N1 virus highlights the role of swine influenza A viruses (swIAVs) in generating novel influenza viruses with pandemic potential. Since 2009, the pdm/09 H1N1 virus has been frequently transmitted to swine and reassorted with the circulating swIAVs, generating many new reassortant viruses bearing pdm/09-derived genes globally. The G4 EA H1N1 viruses, which bore pdm/09-derived internal genes and acquired increased human infectivity, remained the predominant swIAVs in China from 2019 to 2023 and reassorted with the co-circulating swIAVs to generate novel subtype viruses. The internal genes of G4 EA H1N1 viruses originated from the human pdm/09 H1N1 viruses during 2009–2010 and exhibited higher evolutionary rates and greater genetic diversity than those in the human host. This has contributed to increased viral adaptation and pathogenicity in mammals. Therefore, sustained surveillance and immunization efforts are essential to control emerging reassortant swIAVs and protect public health.

Source: Journal of Virology, https://journals.asm.org/doi/10.1128/jvi.00430-25

____

Spatial #variation of infectious virus #load in aggregated day 3 post-inoculation respiratory tract #tissues from #influenza A virus-infected #ferrets

 

ABSTRACT

The ferret model is widely used to study influenza A viruses (IAVs) isolated from multiple avian and mammalian species, as IAVs typically replicate in the respiratory tract of ferrets without the need for prior host adaptation. During standard IAV risk assessments, tissues are routinely collected from ferrets at a fixed time point post-inoculation to assess the capacity for systemic spread. Here, we describe a data set of virus titers in tissues collected from both respiratory tract and extrapulmonary sites 3 days post-inoculation from over 300 ferrets inoculated with more than 100 unique IAVs (inclusive of H1, H2, H3, H5, H7, and H9 IAV subtypes, both mammalian and zoonotic origin). All experiments were conducted by a single research group under a uniform experimental protocol, making it the largest well-controlled publicly available data set to date of discrete tissue titers reported on a per-ferret level. Analysis of these tissues revealed spatial variation in infectious virus load across different tissues, coupled with different interdependence of infectious viral titers throughout the ferret respiratory tract, dependent on the subtype and sequence identity of the IAV. Collectively, this data set enhances our understanding of the diverse heterogeneity exhibited by IAV strains that pose a threat to human health, as observed in tissues collected during the acute phase of infection in mammals, and enables subsequent in-depth analyses spanning a wide array of data science, statistical, and modeling approaches.

IMPORTANCE

The three Rs (reduction, refinement, and replacement, which govern ethical and humane use of animals in scientific research) compel investigators to consider ways to maximize value and impact of in vivo experimentation using a minimum number of animals. One way to achieve this is to aggregate and share publicly results from multiple studies for subsequent investigation. This resource report describes such a data set, reporting infectious virus titers detected in multiple tissues from influenza A virus-infected ferrets, day 3 post-inoculation, aggregated from studies conducted over multiple decades by one research group. We provide usage notes for best practices to inform analysis of these data by other investigators and report results of exploratory studies that illustrate conclusions that can be informed by analyses of this nature. Future public release of like data sets by other groups with similar historical archives may be informed by the practices and formatting described herein.

Source: mSphere, https://journals.asm.org/doi/full/10.1128/msphere.00346-25?af=R

____

#H5N1 #influenza VLPs based on BEVS induce robust functional #antibodies and immune responses

 

Highlights

• The H5N1 influenza virus-like particle vaccines are prepared through baculovirus expression vector system.

• In vitro assessments have confirmed that this VLP vaccine has the correct conformation and functional activity.

• This VLP vaccine induces robust humoral and cellular immune responses in mice, and provides complete protection against infection with the matched strain.

Abstract

Avian influenza virus infections pose a potential pandemic threat. The currently licensed vaccines have inherent limitations, emphasizing the urgent need for improved influenza vaccines. Here, we developed a novel hemagglutinin (HA) virus-like particle (VLP) vaccine candidate through the baculovirus expression vector system (BEVS). The engineered VLPs incorporate HA from H5N1 and matrix 1 (M1) protein from H1N1. Comprehensive characterization revealed that purified HA VLPs exhibited morphological fidelity to native influenza virions while maintaining key viral biological properties. Immunization studies in murine models demonstrated the superior immunogenicity of HA VLPs through a prime-boost regimen. Compared to control groups receiving HA monomer or T4-foldon-trimerized HA formulations, VLP-immunized mice showed significantly enhanced humoral responses and robust cellular immunity. This study provides compelling evidence for advancing VLP-based vaccines as a superior alternative to conventional influenza vaccine formulations.

Source: Virology, https://www.sciencedirect.com/science/article/abs/pii/S0042682225002867?via%3Dihub

____

#Dairy #Environments with #Milk Exposure are Most Likely to Have Detection of #Influenza A Virus

 

Abstract

Highly pathogenic avian influenza virus of the H5N1 subtype has been infecting U.S dairy cattle and spreading among dairy farms since March 2024. H5N1 surveillance systems for dairy farms are needed, but information on whether environmental sampling can inform these systems is lacking. To guide a surveillance framework, we determined the environmental locations on H5N1-affected dairies (n = 25) in four states (California, Colorado, Michigan, and Ohio) that harbored influenza A virus (IAV), and explored sample characteristics that may influence viral detection. A total of 623 samples from environments and sale barns were characterized for IAV and classified into six categories based on location. A total of 94 samples (15.1%) had IAV detected, the majority in the following categories: milking equipment/personal protective equipment, parlor surfaces, and wastewater/lagoons/manure. These results suggest that dairy environments most likely to harbor IAV are those with exposure to milk, although the viral load in environmental samples was typically lower than that of bulk tank milk tested on a subset of farms. Mixed effect modeling was used to explore the relationship between IAV detection, Ct value, and days into an outbreak that samples were collected or the category where samples were collected. Days into an outbreak that samples were collected was associated with IAV detection while category of collection was associated with the measured Ct value. These results may guide H5N1 surveillance efforts on dairies, and can be strengthened by studies that collect samples from farm environmental locations prior to, during, and after H5N1 outbreak periods.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This project was completed using Federal funds provided through the United States Department of Agriculture, Cooperative Agreement 25-9419-0731 and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. 75N93021C00016. S.S.L and AJ.C are supported by discretionary funds from Emory University and gift funds to the Emory Center for Transmission of Airborne Pathogens, provided by the California Dairy Research Foundation and Flu Lab, a California-based organization founded to advance innovative approaches for the prevention and treatment of influenza.

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.09.03.25335023v1

____

The Adoration of the Infant Jesus, Filippo Lippi (1459)

 

Public Domain.

Source: WikiArt, https://www.wikiart.org/en/filippo-lippi/the-adoration-of-the-infant-jesus-1459

____