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Clade 2.3.4.4b #H5N1 #neuraminidase has a long #stalk, which is in contrast to most highly pathogenic H5N1 viruses circulating between 2002 and 2020

ABSTRACT Since 2020, H5N1 highly pathogenic avian influenza (HPAI) viruses of clade 2.3.4.4b have been rapidly spreading in wild birds but have also caused a large number of mammalian infections and more than 70 known human cases . Importantly, this H5N1 clade has also crossed the species barrier into dairy cattle in the US in late 2023/early 2024. The neuraminidase (NA) protein of the N1 subtype can feature truncations in its stalk domain, which have been identified as putative virulence factors in poultry but seem to have a negative impact on transmission in mammals. Since its emergence, the vast majority of HPAI H5N1 A/goose/Guangdong/1/1996-lineage isolates have featured this truncated version of the NA stalk domain. Here, we report that this changed with the 2020 expansion of clade 2.3.4.4b H5N1 and that the majority of isolates—including the strains circulating in dairy cattle—feature a long NA stalk domain . Source: mBio,  https://journals.asm.org/doi/10.1128/mbio.03989-24 _...

#Host #cell entry and #neutralisation sensitivity of the emerging #SARS-CoV-2 #variant #LP.8.1

{Excerpt} Novel SARS-CoV-2 variants continue to emerge, driving waves of COVID-19. The evolution of SARS-CoV-2 took a surprising turn in 2023 with the emergence of BA.2.86, a BA.2-descendant harbouring multiple spike (S) protein mutations, enhancing antibody evasion. Subsequently, several BA.2.86-derived lineages emerged, with JN.1 dominating early and the JN.1-derived variants KP.3.1.1 and XEC dominating late in 2024 . Currently, LP.8.1 is on the verge of becoming dominant. This study provides a preliminary virological characterisation of LP.8.1 and its sublineage LP.8.1.1. (...) Source: Lancet Infectious Diseases,  https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00113-6/fulltext?rss=yes ____

#USA, #Texas announces first #death in #measles #outbreak

The Texas Department of State Health Services is reporting the first death from measles in the ongoing outbreak in the South Plains and Panhandle regions.  The school-aged child who was not vaccinated was hospitalized in Lubbock last week and tested positive for measles. As of Feb. 25, 124 cases of measles have been confirmed in the outbreak since late January. Most of the cases are in children . Eighteen people have been hospitalized over the course of the outbreak. Measles is a highly contagious respiratory illness , which can cause life-threatening illness to anyone who is not protected against the virus. During a measles outbreak, about one in five people who get sick will need hospital care and one in 20 will develop pneumonia. Rarely, measles can lead to swelling of the brain and death. It can also cause pregnancy complications, such as premature birth and babies with low birth weight. Measles can be transmitted by direct contact with infectious droplets or by airborne spread...

#Italy - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Follow up report 17

{Excerpt, Feb. 26 2025 Update} 1) HPAI H5N1 was detected in a Yellow-legged Gull (Larus michahellis) found dead in the Municipality of Rimini, province of Rimini, Emilia Romagna region. 2) HPAI H5N1 was detected in an Eurasian buzzard (common buzzard) (Buteo buteo) found dead in the Municipality of Pramaggiore, province of Venezia, Veneto region 3) HPAI H5N1 was detected in a Eurasian buzzard (common buzzard) (Buteo buteo) found dead in the Municipality of Galzignano Terme, province of Padova, Veneto region 4) HPAI H5N1 was detected in a yellow-legged gull (Larus michahellis) found dead in the Municipality of Padova, province of Padova, Veneto region. 5) HPAI H5N1 was detected in a yellow-legged gull (Larus michahellis) found dead in the Municipality of Stanghella, province of Padova, Veneto region. 6) HPAI H5N1 was detected in a Yellow-legged Gull (Larus michahellis) found dead in the Municipality of Porto Recanati, province of Macerata, Marche region. "The Database of Global Adm...

Mass #mortality #events in the sub- #Antarctic #Indian #Ocean caused by long-distance circumpolar spread of highly pathogenic avian #influenza #H5N1 clade 2.3.4.4b

Abstract Since 2020, the outbreak of highly pathogenic avian influenza (HPAI) virus clade 2.3.4.4b has turned into the largest documented panzootic to date , reaching the sub-Antarctic region and Antarctica via the tip of South America in 2023. Here, we describe its recent arrival into the Indian Ocean sub-Antarctic archipelagos of Crozet and Kerguelen , where we first detected the virus in October 2024 in dead southern elephant seals, king penguins, gentoo penguins, brown skuas and kelp gulls . While the panzootic is ongoing, it has already caused unprecedented and alarming mortalities of southern elephant seals. We collected brain swabs from various seal and bird carcasses, subsequently isolated the virus and obtained 25 novel HPAI H5N1 clade 2.3.4.4b sequences. Our phylogenetic and phylogeographic analyses show that there have been independent introductions of the virus to Crozet and Kerguelen, from the distant South Georgia Islands in the Southern Atlantic , and not from the more n...

#Cambodia confirmed a #fatal pediatric case of #H5N1 avian #influenza virus infection

{Original text in Khmer} Ministry of Health Press Release A Fatal Case of #H5N1 #influenza in a 2-Year-7-Month-Old Child The Ministry of Health of the Kingdom of Cambodia wishes to inform the public that there are a  case of bird flu in a 2-year-old 7-month-old child has been confirmed positive for the influenza virus  H5N1 by the National Institute of Public Health on February 25, 2025. Location : Tangak Village, Romchek Commune, Preah Sdach District, Prey Veng Province. According to doctors , the child died on February 25, 2025 due to the parents  took the child to the hospital, when him developed a serious condition, including fever, cough, fatigue, and difficulty retreating. Severe breathing . According to the investigation, the patient's house has a family chicken farm and there are dead chickens.  About 15 of them were sick and the children were sleeping and playing in the basement near the chicken coop. The national and subnational emergency response teams of ...

Structural basis of #receptor-binding #adaptation of #human-infecting #H3N8 #influenza A virus

ABSTRACT Recent avian-origin H3N8 influenza A virus (IAV) that have infected humans pose a potential public health concern . Alterations in the viral surface glycoprotein, hemagglutinin (HA), are typically required for IAVs to cross the species barrier for adaptation to a new host, but whether H3N8 has adapted to infect humans remains elusive. The observation of a degenerative codon in position 228 of HA in human H3N8 A/Henan/4-10/2022 protein sequence , which could be residue G or S, suggests a dynamic viral adaptation for human infection. Previously, we found this human-isolated virus has shown the ability to transmit between ferrets via respiratory droplets , with the HA-G228S substitution mutation emerging as a critical determinant for the airborne transmission of the virus in ferrets. Here, we investigated the receptor-binding properties of these two H3N8 HAs. Our results showed H3N8 HAs have dual receptor-binding properties with a preference for avian receptor binding , and G228S...

#Dynamics of a #Panzootic: Genomic #Insights, #Host Range, and #Epidemiology of the Highly Pathogenic Avian #Influenza A(#H5N1) Clade 2.3.4.4b in #USA

Abstract In late 2021, Eurasian-lineage highly pathogenic avian influenza (HPAI) A(H5N1) viruses from HA clade 2.3.4.4b were first detected in the United States . These viruses have caused severe morbidity and mortality in poultry and have been detected in numerous wild and domestic animals , including cows and humans . Notably, infected cows transmitted the virus to cats , causing extreme pathogenicity and death. While human-to-human spread of the virus has not been recorded, efficient transmission of the bovine-origin virus has also led to extreme pathogenicity and death in ferret models . Recently, markers in PB2 (E627K) and HA (E186D, Q222H), indicating mammalian adaptation mutations , were detected in an H5N1-infected patient manifesting critical illness in Canada . These, combined with instances of interspecies spread of the virus , have raised global public health concerns. This could highlight the potential for the virus to successfully adapt to mammals, posing a serious risk o...

#Efficacy and #safety of #sipavibart for #prevention of #COVID19 in individuals who are immunocompromised (SUPERNOVA)...

Summary Background Sipavibart is an anti-spike monoclonal antibody that neutralises SARS-CoV-2 with exceptions, including Phe456Leu-containing variants (eg, KP.2* and KP.3*). This trial assessed sipavibart efficacy and safety for prevention of symptomatic COVID-19 in participants who are immunocompromised. Methods In this ongoing, double-blind, international, phase 3 trial , we enrolled participants who were immunocompromised and aged 12 years or older at 197 hospitals, university health centres, and clinical trial units in 18 countries. Participants were randomly allocated 1:1 to a sipavibart group (intramuscular sipavibart 300 mg on days 1 and 181) or a comparator group (tixagevimab 300 mg–cilgavimab 300 mg on day 1 and placebo on day 181 or placebo on days 1 and 181), stratified by previous COVID-19 vaccination and infection status and use of tixagevimab–cilgavimab. The primary efficacy outcomes were symptomatic COVID-19 caused by any variant or symptomatic COVID-19 caused by non-Ph...

#Exposure and #survival of wild #raptors during the 2022–2023 highly pathogenic #influenza a virus #outbreak

Abstract The global outbreak of clade 2.3.4.4b H5N1 highly pathogenic influenza A virus (HP H5N1) has had an unprecedented impact on wild birds including raptors , but long-term population impacts have not been addressed. To determine if raptors survive infections with HP H5N1, raptors from the upper Midwest United States were serologically tested for antibodies to influenza A virus (IAV), H5 and N1. Raptors were sampled at The Raptor Center’s (University of Minnesota) wildlife rehabilitation hospital and at Hawk Ridge Bird Observatory. Samples were tested for IAV antibodies using a commercially available blocking ELISA, with positive samples tested for antibodies to H5 and N1. Antibodies to IAV were detected in 86 out of 316 individuals representing 7 species. Antibodies to H5 and N1 were detected in 60 individuals representing 6 species . Bald eagles had the highest seroprevalence with 67/97 (69.1%) seropositive for IAV and 52 of these 67 (77.6%) testing positive for antibodies to bo...

#Monkeypox Virus Occurrence in #Wastewater #Environment and Its Correlation with Incidence Cases of #Mpox: A Systematic Review and Meta-Analytic Study

Abstract The COVID-19 pandemic has increased the interest in the use of wastewater-based surveillance (WBS) strategy for infectious disease monitoring, especially when clinical cases are underreported. The excretion of monkey virus (MPXV) in the feces of both symptomatic and preclinical individuals has further driven the interest in WBS applicability to MPXV monitoring in wastewater to support its mitigation efforts. We performed a systematic review with meta-analysis, using six databases to assess MPXV detection in wastewater. We performed a random-effects model meta-analysis to calculate the pooled prevalence at a 95% confidence interval (95% CI). Also, we carried out a subgroup analysis according to the country regions and a sensitivity analysis excluding studies classified as having a high risk of bias. The overall MPXV positivity rate in wastewater was estimated at 22% (95% CI: 14−30%; I2 = 94.8%), with more detection rate in North America (26%, 95% CI: 8–43%) compared to Europe a...

The #Impact of Highly Pathogenic Avian #Influenza #H5N1 in the #USA: A Scoping #Review of Past #Detections and Present #Outbreaks

Abstract Highly Pathogenic Avian Influenza H5N1 (HPAI H5N1) was first detected in chickens in Scottland in 1959 and has since circulated globally, causing regular outbreaks among different animal species, as well as incidental infections in humans . In this scoping review, the epidemiology and impact of HPAI H5N1 among migratory birds, poultry, and cattle in the United States were analyzed, with a particular focus on outbreaks since January 2022. Following PRISMA guidelines, a total of 27 articles were identified for this review. Publicly available data and reports from the USDA and CDC were also evaluated and summarized. The identified articles primarily included epidemiological studies of detections in wild birds, mammals, and case reports on H5N1 and transmission dynamics among cattle , with a notable absence of poultry-focused reports . Wild birds, especially migratory species, have played an important role in virus dissemination. Studies among mammals , including seals, bears, and...

Highly Pathogenic Avian #Influenza A (#H5N1) Clade 2.3.2.1a virus #infection in domestic #cats, #India, 2025

Abstract In January 2025, the highly pathogenic avian influenza A(H5N1) virus clade 2.3.2.1a infection was detected in domestic cats and whole-genome sequencing of two cat H5N1 isolates was performed using the Oxford Nanopore MinION sequencing platform. Phylogenetic analysis revealed the circulation of triple reassortant viruses in cats. Although cat viruses lacked classic mammalian adaptation markers they carried mutations associated with enhanced polymerase activity in mammalian cells and increased affinity for α2-6 sialic acid receptor suggesting their potential role in facilitating infection in cats. The identification of reassortant HPAI H5N1 clade 2.3.2.1a viruses in domestic cats in India highlights the urgent need for enhanced surveillance in domestic poultry, wild birds, and mammals, including humans, to track genomic diversity and molecular evolution of circulating strains. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.02.23.638954v1 ____

In-hospital #outcomes and 6-month follow-up results of #patients supported with #ECMO for #COVID19 from the 2nd wave to end of pandemic (EuroECMO-COVID)...

Summary Background Extracorporeal membrane oxygenation (ECMO) for COVID-19 was thoroughly assessed during the first pandemic wave , but data on subsequent waves are limited. We aimed to investigate in-hospital and 6-month survival of patients with COVID-19 supported with ECMO from the second pandemic wave (Sept 15, 2020) until the end of the pandemic (March 21, 2023, announced by WHO). Methods EuroECMO-COVID is a prospective, observational study including adults (aged ≥16 years) requiring ECMO respiratory support for COVID-19 from 98 centres in 21 countries. We compared patient characteristics and outcomes between in-hospital survivors and non-survivors. Mixed-effects multivariable logistic regressions were used to investigate factors linked to in-hospital mortality. 6-month survival and overall patient status were determined via patient contact or chart review. This study is registered with ClinicalTrials.gov, NCT04366921, and is complete. Findings We included 3860 patients (2687 [69·...

Structure-based #Design of Chimeric #Influenza #Hemagglutinins to Elicit Cross-group #Immunity

Abstract Antigenic variability among influenza virus strains poses a significant challenge to developing broadly protective , long-lasting vaccines . Current annual vaccines target specific strains, requiring accurate prediction for effective neutralization. Despite sequence diversity across phylogenetic groups, the hemagglutinin (HA) head domain's structure remains highly conserved. Utilizing this conservation, we designed cross-group chimeric HAs that combine antigenic surfaces from distant strains. By structure-guided transplantation of receptor-binding site (RBS) residues, we displayed an H3 RBS on an H1 HA scaffold . These chimeric immunogens elicit cross-group polyclonal responses capable of neutralizing both base and distal strains. Additionally, the chimeras integrate heterotrimeric immunogens, enhancing modular vaccine design. This approach enables the inclusion of diverse strain segments to generate broad polyclonal responses. In the future, such modular immunogens may se...

A Vestal Virgin Crowned With Flowers, Jacques-Louis David (1783)

  Public Domain. Source: WikiArt,  https://www.wikiart.org/en/jacques-louis-david/a-vestal-virgin-crowned-with-flowers ____

#Coronavirus Disease Research #References (by AMEDEO, Feb. 23 '25)

  Antiviral Res INOUE A, Ichikawa T, Wada D, Maruyama S, et al M49L and other drug resistance mutations emerging in individuals after administration of ensitrelvir in Japanese clinical settings. Antiviral Res. 2025;236:106118. PubMed           Abstract available ZIAN D, Iaconis D, Nenci S, Crusco A, et al The Efficiency of High-Throughput Screening (HTS) and in-silico data analysis during medical emergencies: identification of effective antiviral 3CLpro inhibitors. Antiviral Res. 2025 Feb 18:106119. doi: 10.1016/j.antiviral.2025.106119. PubMed           Abstract available Clin Infect Dis LUETKEMEYER AF, Chew KW, Lacey S, Hughes MD, et al Ensitrelvir for the Treatment of Nonhospitalized Adults with COVID-19: Results from the SCORPIO-HR, Phase 3, Randomized, Double-blind, Placebo-Controlled Trial. Clin Infect Dis. 2025 Feb 17:ciaf029. doi: 10.1093. PubMed       ...

#Influenza and Other Respiratory Viruses Research #References (by AMEDEO, Feb. 23 '25)

  Antiviral Res SCHREIBER A, Ludwig S Host-targeted antivirals against SARS-CoV-2 in clinical development - Prospect or disappointment? Antiviral Res. 2025;235:106101. PubMed           Abstract available WU Q, Wu H, Hu Y, Zheng X, et al Immune evasion of Omicron variants JN.1, KP.2, and KP.3 to the polyclonal and monoclonal antibodies from COVID-19 convalescents and vaccine recipients. Antiviral Res. 2025 Jan 24:106092. doi: 10.1016/j.antiviral.2025.106092. PubMed           Abstract available XU M, Zhang Z, Sun Y, Mai H, et al IgA class switching enhances neutralizing potency against SARS-CoV-2 by increased antibody hinge flexibility. Antiviral Res. 2025 Jan 17:106082. doi: 10.1016/j.antiviral.2025.106082. PubMed           Abstract available Biochemistry LEE S, Yan S, Dey A, Laederach A, et al A Cascade of Conformational Switches in SARS-CoV-2 Frame...

#Genomics of novel #influenza A virus (#H18N12) in #bats, Caribe #Colombia

Abstract Influenza viruses are highly capable of mutating and adapting in mammalian hosts . While these viruses have been extensively studied in birds, research on their presence in bats has been limited. However, influenza viruses circulating in bats have shown notable molecular divergence . The present study aimed to characterize the phylogenetic, evolutionary, and antigenic relationships of an influenza A virus detected in the fishing bat Noctilio albiventris . As part of a pathogen surveillance study of public health interest, 159 rectal samples were collected from bats in the Colombian Caribbean . The samples were sequenced using RNA-Seq. A genome (eight viral contigs) associated with the Orthomyxoviridae family was identified in a pool. Most segments showed approximately 90% similarity with H18N11, except for the neuraminidase. Analysis of the N protein shows that occupies a basal position relative to the N11 subtype, with its divergence date estimated to be approximately 50 year...

A #framework for #tracking global #progress on #preparedness for #respiratory #pandemics

{Summary} 1 Introduction The COVID-19 pandemic underscored the urgency of ensuring that the world is prepared for the next major respiratory pathogen pandemic (1). Corresponding with World Health Assembly resolutions WHA58 .5 (2) and WHA74.7 (3), WHO is committed to supporting Member States with pandemic preparedness planning through the provision of guidance and technical assistance . Following on from the PRET Global Meeting in April 2023, WHO has finalized guidance on Preparedness and resilience for emerging threats (PRET) module (1): planning for respiratory pathogen pandemics. This module acknowledges that similar systems and capacities can be used to prevent, prepare for and respond to different respiratory pathogens. The module (4) has three overarching objectives: - to guide countries and partners in developing or updating their integrated approach to respiratory pathogen pandemic preparedness for equitable and robust response; - to focus attention on the actions needed to stre...