ETIDIOH - NEW

  Highlights •  Human antibody HB420 cross-reacts with neuraminidases from H3N2 and H5N1 •  HB420 engages the neuraminidase active site via a single Asp residue •  Germline HB420 is N2 specific but gains reactivity to N1 through somatic mutation •  HB420 provides in vivo protection against both H3N2 and H5N1 Summary The ongoing spread of highly pathogenic avian influenza H5N1 clade 2.3.4.4b virus in animals and its occasional spillover to humans have raised concerns about a potential H5N1 pandemic . Although recent studies have shown that pre-existing human antibodies can recognize H5N1 neuraminidase , the molecular basis of how this cross-reactivity develops remains poorly understood. In this study, we used a phage display antibody library derived from 245 healthy donors to isolate an antibody, HB420, that cross-reacts with neuraminidases of human H3N2 and avian H5N1 clade 2.3.4.4b viruses and confers protection in vivo. Cryogenic electron microscopy analysis r...

  Abstract Most emerging human infectious diseases are derived from animals , and monitoring such zoonoses is imperative to help prevent future outbreaks . In this Forum , we discuss the knowledge gaps in our current understanding of viral ecology, global disparities in virus discovery , and the applications of artificial intelligence in infectious disease monitoring. Source: Cell Host & Microbe,  https://www.cell.com/cell-host-microbe/abstract/S1931-3128(25)00429-9?rss=yes ____

  SUMMARY OF CRISIS AND KEY FINDINGS   The fragile Gaza ceasefire announced on 9 October 2025 marked a momentous but precarious juncture in the ongoing conflict.{3}  The ceasefire remains in place but is fragile, and violations from both sides continue.{4}  When the ceasefire was agreed in mid-October , the UN Relief Chief Tom Fletcher outlined a 60-day plan to deliver vital aid to people in Gaza, stressing that full implementation requires more crossings, rapid and unimpeded access , sustained fuel entry, restored infrastructure , protection of aid workers , and adequate funding.{5}   While humanitarian aid has begun to flow into Gaza offering a measure of relief, uncertainty persists. Meanwhile, the Rafah Crossing as well as other crossings in the north remain closed , limiting efforts to alleviate Gaza’s humanitarian crisis.{6}  According to the Ministry of Health (MoH) in Gaza, the casualty toll among Palestinians since 7 October 2023 , as reported...

  Abstract Influenza viruses cause hundreds of thousands of infections globally every year. In the past century, seasonal influenza viruses have included H1N1, H2N2 or H3N2 strains . H2N2 influenza viruses circulated in the human population between 1957-1968 . Previously, our group demonstrated a lack of H2N2 influenza virus immunity in individuals born after 1968 , as well as the effectiveness of hemagglutinin (HA) based vaccines for multiple influenza virus subtypes. In this study, H2 antigenic maps and radial graphs were generated using previously published data from H2 HA vaccinations of ferrets and seasonal influenza vaccinations of humans . The antigenic maps revealed a stark difference in clustering of HA antigens between the ferrets and humans, and the radial graphs showed specific antigen recognition varies greatly between different influenza preimmune ferrets . These maps also revealed the significant impact that different pre-existing immunities have on antigenic recogni...

  Suspicion of avian influenza was raised at the Mirovice slaughterhouse. The suspicion concerned slaughtered ducks originating from a commercial fattening duck farm (Primary outbreak No. HPAI1-2/2025). A suspicion of HPAI was raised based on the pathological-anatomical findings and the information that there has been increased mortality in the farm. The official veterinary officer collected samples of ducks from the slaughterhouse for testing, which were sent by courier to the National Reference Laboratory, and issued preliminary veterinary measures for the slaughterhouse to prevent the spread of the disease. In connection with the suspicion of HPAI at the slaughterhouse (Secondary outbreak No. HPAI1-3/2025), commercial poultry farm with a fattening ducks. During the on-site inspection, it was found that the animals were dying massively (in total 2 700 birds and the high mortality still ongoing) and showing clinical signs (lethargy, ruffled feathers, and neurological symptoms). Th...

  A poultry farm in Csongrád-Csanád Region. Source: WOAH,  https://wahis.woah.org/#/in-review/7005 ____

  Wild Whooper Swans in the Arhangay Region. Source: WOAH,  https://wahis.woah.org/#/in-review/7007 ____

  Abstract The spread of H5N1 clade 2.3.4.4b in dairy herds raises concerns about zoonotic transmission due to its high viral load in milk , a key contact point between livestock and humans . H5N1 clade 2.3.4.4b exhibits tropism for the mammary gland , with milk from infected animals containing high levels of infectious virus , posing potential risks to offspring via breastfeeding . Using a lactating ferret model , we demonstrate that mammary gland infection with bovine H5N1 transmits the virus to suckling kits , resulting in neonatal mortality . Viral RNA levels increased in milk and remained high in mammary tissue, with infected kits exhibiting elevated viral RNA in the oral and nasal cavities and feces . Additionally, we detected the H5N1 receptor, α2,3 sialic acid , in ferret and human mammary tissue . These data demonstrate that H5N1 clade 2.3.4.4b infection in lactating dams leads to mastitis-related disease and transmits to suckling pups, resulting in mortality among neonate...

  Abstract The highly pathogenic H5N1 avian influenza A virus (IAV) clade 2.3.4.4b has spread globally and spilled over into multiple mammalian species , raising concerns about its pandemic potential . In late 2022, clade 2.3.4.4b viruses devastated seabird and marine mammal populations along the Pacific coast of South America . Here, we report the first evidence of H5 IAV infections in wild bats globally, focusing on common vampire bats (Desmodus rotundus) in coastal areas of Peru . Longitudinal serological screening , stable isotope analysis and metabarcoding revealed repeated exposures to H5 IAVs in vampire bats which feed on coastal wildlife species heavily impacted by the 2.3.4.4b epizootic, but no evidence of infection in populations without access to marine prey. We further report bat gene flow between IAV-exposed and IAV-naive populations , and IAV infections in a vampire bat colony that fed on both marine and terrestrial livestock prey, providing insights into how future I...

  Summary -- What is already known about this topic? - A total of 117 H9N2 cases of human infection of Chinese origin had been reported to the World Health Organization (WHO) by May 9, 2025, with 22 of them originating in Hunan Province. -- What is added by this report? - This article reported on the investigation of three new H9N2 avian influenza virus (AIV) infections detected in Changsha, Hunan Province , in April 2025. No epidemiological link was found among them. Exposure to live poultry was identified as the primary risk factor for infection. Sequence analysis of the three H9N2 AIVs showed a similarity of 99.71%–99.82% between hemagglutinin (HA), and the homology of the neuraminidase (NA) genes was 98.41%–99.83%. Although the tests showed that the HA had enhanced binding ability to upper respiratory tract cells’ receptors , no evidence of sustained human-to-human transmission has been found so far. -- What are the implications for public health practice? - This study indicate...

  Summary -- What is already known about this topic? - The H3N8 avian influenza virus (AIV) demonstrates considerable capacity for interspecies transmission and has been documented in multiple mammalian hosts , including equine and canine species. During 2022–2023, three laboratory-confirmed human infections with H3N8 were reported in China, heightening public health concerns about the zoonotic spillover potential of H3 subtype AIVs. -- What is added by this report? - This study reports the isolation of a genetically reassorted, low-pathogenicity H3N8 avian influenza virus (AIV) from an islet in Niukouyu Wetland Park, Beijing Municipality — the first detection of this viral strain in a wild environment within the city. Throat swabs collected from park staff tested negative for influenza viruses. Phylogenetic analysis demonstrated that the viral hemagglutinin gene originated from the Eurasian lineage, while the neuraminidase gene was derived from the North American lineage . Althoug...

  Abstract Influenza pandemics arise when novel influenza virus subtypes emerge in populations with little or no pre-existing immunity . The recent expansion of H5N1 virus circulation in mammals — including documented spread in cattle and sporadic human infections — coupled with the emergence of mutations associated with enhanced pandemic potential , underscores the persistent threat of novel influenza strains. Pandemic preparedness critically depends on developing effective vaccines capable of providing broad protection across diverse viral strains. While vaccination remains the most effective strategy for preventing influenza and its complications, pandemic vaccine development faces substantial challenges . These include the rapid mutation rates characteristic of influenza viruses, driven by error-prone RNA replication, broad host range, environmental selection pressures, and frequent genetic recombination. Such factors complicate predictions of which strain will trigger the next...

  Authors: Freja CM Kirsebom{1}, Catherine Thompson{2}, Tiina Talts{2}, Beatrix Kele{2}, Heather J Whitaker{3}, Nurin Abdul Aziz{1}, Christopher Rawlinson{1}, Rebecca E Green{1}, Catherine Quinot{1}, Nicholas Gardner{1}, Elizabeth Waller{1}, Alex Allen{1}, Conall H Watson{1,4}, Suzanna LR McDonald{1}, Maria Zambon{2}, Richard Pebody{4,5}, Mary Ramsay{6,7}, Katja Hoschler{2}, Anika Singanayagam{*2,4}, Jamie Lopez Bernal{*1,4}  {*} Joint last authors  {1} Immunisation and Vaccine-preventable Diseases Division, UK Health Security Agency, Colindale, London  {2} Respiratory Virus Unit (RVU), UK Health Security Agency, Colindale, London  {3} Modelling Division, UK Health Security Agency, Colindale, London  {4} NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London, United Kingdom  {5} Epidemic and Emerging Infections Directorate, UK Health Security Agency, Colindale, London  {6} Public Health Programmes Directorate, UK H...

  Abstract Between 2022 and 2025, high pathogenicity avian influenza (HPAI) H5N1 clade 2.3.4.4b was detected in poultry and wildlife across most countries in Central and South America . The epizootic peaked in 2023, subsided in 2024, and resurged in 2025 . In Central America , outbreaks in wildlife were few and small, and mostly affected pelicans . In contrast, South America experienced unprecedented mass mortality in colonial seabirds and pinnipeds , including endangered and endemic species. Notably, viral adaptation enabled mammal-to-mammal transmission in pinnipeds and rapid viral spread across multiple countries along the Pacific and Atlantic coasts . Subsequent introductions to subantarctic islands and Antarctica stemmed from South American viruses. In February 2025, a novel reassortant virus emerged, recombining HPAI H5N1 B3.2 genotype with South American low pathogenicity avian influenza viruses . In May 2025, HPAI H5N1 viruses re-emerged in Brazil , causing a series of outb...

{Northern Ireland} 56 week-old hens-table egg layers. Positive test for HPAI H5N1, clinical signs presented prior to testing. 10-week-old approx. turkey broilers. Positive test for HPAI H5N1, clinical signs presented prior to testing. Source: WOAH,  https://wahis.woah.org/#/in-review/7000 ____

  A poultry farm in Sachsen Region. Source: WOAH,  https://wahis.woah.org/#/in-review/7002 ____

Wild Mute Swans in Kiev Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6994 ____

  Abstract In developing countries particularly in field conditions unfavorable environmental conditions, lack of availability of appropriate transport media (TM) and maintenance of cold chain during transport; sample collection , storage, and transportation is more challenging . Considering these facts, five TM out of which three laboratory-based media named phosphate-buffered saline (PBS), 50% glycerol + PBS , and normal saline (NS) and two commercially available media including viral transport medium (VTM), charcoal based viral transport medium (CVTM) were compared to protect infectivity of the H5N1 influenza virus . Spiked fecal sample and allantoic fluid with and without these TM were placed in field simulatory storage and transportation conditions and in every 12 h time interval these samples were tested for virus isolation in embryonated chicken egg inoculation and identification by HA test and RT PCR upto 7 days. Survivability of the virus was detected by calculating the pe...

  Abstract Background :  Lassa fever (LF) is an acute viral hemorrhagic illness endemic to West Africa, with no licensed vaccines or targeted treatments available, highlighting a critical gap in global health preparedness. T cell-mediated immunity plays a central role in viral control and survival. Synthetic DNA vaccines offer a promising strategy to induce both humoral and cellular immunity against LF. Methods :  A Phase 1b, randomized, double-blind, placebo-controlled trial was conducted to assess the safety, tolerability, and immunogenicity of INO-4500 , a DNA vaccine encoding the Lassa virus (Josiah strain) glycoprotein precursor (GPC). A total of 220 healthy adults were randomized to receive either 1 mg or 2 mg of INO-4500 (intervention), or placebo, administered intradermally (ID) followed by electroporation (EP) at Day 0 and Week 4. Safety was evaluated through Week 48. Primary immunogenicity endpoints included humoral and cellular immune responses at multiple time...

  Abstract Infectious diseases are often observed to have different epidemiology in different countries , which arises due to various factors including those that are ecological, socioeconomic, and healthcare-related . Such variability can sometimes be best captured through looking at groups of countries that are similar within-group but variable between-group. In this study we use statistical learning methods to generate data-driven disease-centric groupings of countries rather than those developed for administrative or political reasons by e.g. the WHO, World Bank, and the United Nations. In particular, we apply hierarchical clustering to group countries based on shared disease-relevant characteristics for zoonotic H5N1 influenza . Using statistical methods such as classification and regression trees (CART)-based imputation and dynamic tree cutting, the analysis accounts for missing data and identifies epidemiologically (rather than politically or economically) meaningful cluster...