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Re-infection with #SARS-CoV-2 is associated with increased #antibody breadth and potency against diverse #sarbecovirus strains

  ABSTRACT The ease with which emerging SARS-CoV-2 variants escape neutralizing antibodies limits the protection afforded by a prior exposure , be it infection or vaccination. While rare, broadly neutralizing antibodies with activity toward diverse sarbecoviruses have been detected in convalescent serum . Motivated by findings that plasma responses show increased neutralization breadth and potency with continued antigen exposure , we isolated monoclonal antibodies (mAbs) after a SARS-CoV-2 re-infection and compared them to those isolated 1 year prior, after the first breakthrough infection. Among clonal lineage members identified at both time points, mAbs from the later time point showed improved neutralization potency and breadth . One mAb isolated after re-infection, C68.490, targets a conserved region in the receptor binding domain and shows remarkable activity not only against SARS-CoV-2 variants, but also diverse sarbecoviruses from more distant clades present in animal reserv...
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#Mpox Multi-country external #situation #report no. 63, published 24 February 2026 (#WHO, summary)

  Highlights     • Transmission of mpox continues in sexual networks , affecting both women and men , and in some historically endemic areas .  - All clades of monkeypox virus (MPXV) continue to circulate.  - Unless mpox outbreaks are rapidly contained and human-to-human transmission is interrupted , there is a risk of sustained community transmission .  • In January 2026, 50 countries across all WHO regions reported a total of 1334 new confirmed mpox cases , including three deaths (case fatality ratio [CFR] 0.2%).  - Of these cases , 66% were reported in the African Region.  • Four regions observed a decline in confirmed cases in January, compared to December 2025, while the European Region reported an increase in confirmed cases. • Twenty countries in Africa reported active transmission of mpox in the last six weeks (5 January – 15 February 2026), with 1142 confirmed cases, including four deaths (CFR 0.4%).  - Countries reporting the highes...

#Argentina - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

  {A Coscoroba Swan. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=179069673 } ___ {A Black-Necked Swan. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=178158764 } ___ {A Fulvous Whistling Duck. By JeffreyGammon - Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=158156460 } ___ {A Brown-Hooded Gull. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=179073441 } ____ Contact with wild migratory birds present in the area is presumed to be the likely source of infection. Virological analysis has identified the presence of the H5 subtype of high pathogenicity avian influenza (HPAI). The determination of the neuraminidase subtype is pending in order to complete the chara...

#Argentina - High pathogenicity avian #influenza #H5 viruses (Inf. with) (#poultry) - Immediate notification

  At a heavy breeding poultry farm located in the province of Buenos Aires , an increase in mortality and the presence of clinical signs consistent with high pathogenicity avian influenza (HPAI) were observed. Given the clinical suspicion, official intervention was carried out, including a health inspection and the collection of diagnostic samples for processing. Laboratory analyses confirmed a positive result for high pathogenicity avian influenza subtype H5 (HPAI H5). The event occured on a farm raising heavy breeding stock. On 21/02/2026, the National Service of Agri-Food Health and Quality (SENASA) received a notification concerning mortality and clinical signs consistent with high pathogenicity avian influenza (HPAI) which began on 19/02/2026, as reported by the reporting person. On 22/02/2026, the suspicion was officially addressed with the restriction of the establishment and taking of samples for official diagnosis. On 23/02/2026, the samples tested positive for HPAI H5. Al...

#Report on #influenza viruses received and tested by the #Melbourne #WHO CC for #Reference and Research on #Influenza during 2024

  Abstract As part of its role in the World Health Organization (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received 12,180 human influenza-positive samples during 2024 . Viruses were analysed for their antigenic, genetic, and antiviral susceptibility properties . Selected viruses were propagated in qualified cells or embryonated hens’ eggs for potential use in seasonal influenza virus vaccines. During 2024 , influenza A( H1N1 )pdm09 and A( H3N2 ) viruses predominated , accounting for 33% and 42%, respectively, of all viruses received, compared to 5% for influenza B/Victoria . Of note, one influenza A(H5N1) virus was also received in 2024 . The majority of A(H1N1)pdm09 (98%), A(H3N2) (88%) and influenza B (100%) viruses analysed at the Centre were found to be antigenically and genetically similar to the respective WHO recommended vaccine strains for the Southern Hemisphere in 2024...

Longitudinal #assessment of functional #antibodies to a novel #influenza virus strain across age groups

  Abstract Newly emerging influenza virus strains pose a constant threat as they encounter a population lacking neutralizing antibodies against the new strain . However, cross-reactive non-neutralizing antibodies (nnABs) may be present and assist in mitigating disease symptoms via various effector mechanisms, including antibody-dependent cellular cytotoxicity (ADCC). Although nnABs to influenza virus have received more attention lately , little information is available on their age-related prevalence , steady-state levels, functional properties , and changes in these parameters over time. Using longitudinal samples from adolescents, adults, and older adults , collected before and after the 2009 swine flu pandemic , we comprehensively characterized the specificity and functionality of nnAB responses against H1N1 pandemic 2009 (H1N1pdm09) virus . Remarkably, all participants exhibited cross-reactive antibodies to this virus before having encountered it through infection or vaccinatio...

Evaluating #primer and #probe #mismatch tolerance in an #Influenza A #matrix gene RT #qPCR using contemporary human and zoonotic strains

  Abstract Background :  Genetic drift and host-associated adaptation in influenza A viruses threaten the long-term reliability of RT-qPCR-based diagnostics , particularly when nucleotide mismatches arise within primer and probe binding regions . Conventional assay evaluations often emphasize sequence conservation but rarely assess functional mismatch tolerance across divergent subtypes and hosts.  Methods :  We performed an in silico evaluation of a matrix (M) gene–targeted RT-qPCR assay by aligning primer and probe binding regions against 22 H1N1 isolates and representative H3N2 and H5N1 reference strains, including recent zoonotic isolates from avian and bovine hosts . Nucleotide mismatches were identified, quantified, and mapped relative to assay components and oligonucleotide termini. Mismatch burden was summarized by subtype and assay region.  Results :  H1N1 isolates exhibited complete conservation across primer and probe regions. In contrast, H3N2 a...

Primary bovine embryonic #fibroblasts demonstrate variable #fitness following #infection with avian influenza #H5N1 strains and are susceptible to a recently circulating human #H1N1pdm09 strain

  ABSTRACT The recent emergence of highly pathogenic avian influenza (HPAI) H5N1 (clade 2.3.4.4b, genotype B3.13) in dairy cattle presents substantial challenges to the agricultural sector and public health. Mechanistic studies of infection and transmission in cattle have proven difficult due to animal handling restrictions and the limited availability of established cell culture models. Primary bovine embryonic fibroblasts (BeEFs) were isolated and investigated here as a model to study influenza A virus (IAV) infection dynamics. We compared sialylation profiles , infectious virus production, viral replication, and plaque morphology in BeEFs following infection with the bovine HPAI H5N1 and an earlier 2.3.4.4b genotype (B1.1) isolated in 2022. The data presented here demonstrate increased expression of α-2,3 sialic acids compared to α-2,6 sialic acids in BeEFs , similar to sialylation profiles previously reported in bovine mammary tissue . These data also display increased viral fi...

#SARS-CoV-2 Error Catastrophe Under #Molnupiravir: #Mutagenic Enhancement Enables Viral #Persistence with Impaired Fitness

  Abstract Molnupiravir induces mutations that render severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication-competent through error catastrophe mechanisms . Previous studies showed no resistant virus emergence during prolonged molnupiravir treatment, with no resistant variants reported . However, these approaches were limited by genetic uniformity at passage initiation. To investigate viral population dynamics under enhanced genetic diversity, we employed mutagenic pre-treatment using 5-fluorouracil (5-FU) and favipiravir to generate diverse quasi-species populations before molnupiravir selection pressure. Viral populations were treated with stepwise increasing molnupiravir concentrations (10 μM ⟶ 25 μM ⟶ 40 μM) over ten serial passages . Viral detectability, plaque morphology, and mutation accumulation were analyzed using molecular and sequencing approaches . Only high-concentration favipiravir (1000 μM) pre-treatment maintained detectable viral RNA through ten ...

#Uruguay - #Influenza A #HxNx viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

{Coscoroba Swan. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0,  https://commons.wikimedia.org/w/index.php?curid=179069673 } ___ On February 19, 2026, park rangers from the National System of Protected Areas (SNAP) reported observing two birds of the same species displaying neurological signs . They were able to access one of the animals, which subsequently died. The carcass was properly preserved and sent to the official laboratory for analysis. The emergency protocol was immediately activated. An area of 5 kilometres around the point of detection was defined. There are no commercial poultry farms within the area under analysis. The Official Veterinary Services of the departments of Maldonado and Rocha are visiting establishments in the area. The survey consists of identifying the establishment and owner; georeferencing; confirming the presence of birds (chickens/multiple species); evaluating management conditions and the existen...

The #bovine mammary #gland as a crucible for zoonotic #influenza virus emergence: Receptor-mediated #adaptation of HPAI #H5N1 clade 2.3.4.4b

  Abstract The recent emergence of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in U.S. dairy cattle marks a pivotal shift in the ecology of influenza A viruses (IAVs), signaling an unexpected expansion into a major livestock species . This review explores the molecular mechanisms underpinning this cross-species transmission , focusing on the unique sialic acid receptor landscape of the bovine mammary gland as a critical determinant. We synthesize emerging evidence that this tissue, which co-expresses both avian-type (α2,3-linked) and human-type (α2,6-linked) sialic acid receptors , functions as a novel biological crucible for viral adaptation . Within this environment, H5N1 virus faces selective pressure for hemagglutinin (HA) mutations —such as Q226L and N193D—that can alter receptor binding specificity toward human-like glycans , potentially bridging the species barrier. Recent studies confirm that bovine H5N1 virus isolates exhibit dual receptor-binding avidity ...

Hematogenous #neuroinvasion and genotype-dependent #transmission of #influenza A #H5N1 viruses in the #cat host

  Abstract The spillover of highly pathogenic avian influenza (HPAI) A H5N1 virus to mammalian hosts raises major concerns due to its pandemic potential . Cats are frequently affected mammals, often succumbing to systemic and neurological disease . Here, we characterized the pathogenesis and transmissibility of two H5N1 genotypes, B3.13 and D1.1, in cats . Infected cats exhibited high-level viremia and virus shedding in nasal, oral, and fecal secretions were consistently detected. The virus replicated initially in the upper respiratory tract and lungs , followed by systemic dissemination and neuroinvasion . Notably, the virus crossed the blood-brain-barrier by infecting endothelial cells , spreading to astrocytes and neurons , causing multifocal encephalitis . D1.1-virus infection caused protracted disease with lower shedding and no transmissibility , whereas B3.13 virus caused rapid onset with efficient shedding and transmission. These findings reveal critical H5N1 neuropathogenes...

History of Mass Transportation: The C&O class M-1 #500 Baldwin Steam Turbine Locomotive

  By The only mark on the card is EKE. - eBay itemcard frontcard back, Public Domain,  https://commons.wikimedia.org/w/index.php?curid=17618573 Source:  Link:  https://en.wikipedia.org/wiki/Baldwin_Locomotive_Works ____

The Fight between Carnival and Lent, Pieter Bruegel the Elder (1559)

  Public Domain. Source:  Link:  https://www.wikiart.org/en/pieter-bruegel-the-elder/the-fight-between-carnival-and-lent-1559-1 ____

#Coronavirus Disease Research #References (by AMEDEO, Feb. 21 '26)

  Antiviral Res LIU Q, Tang B, Xuan X, Wang H, et al The potential of leritrelvir repositioning for the treatment of coxsackievirus B4 and common enterovirus infections. Antiviral Res. 2026 Feb 16:106367. doi: 10.1016/j.antiviral.2026.106367. PubMed           Abstract available Emerg Infect Dis KASAI M, Sakuma H, Suzuki M, Nishiyama M, et al Life-Threatening SARS-CoV-2-Associated Encephalopathy and Multiorgan Failure in Children, Asia and Oceania, 2022-2024. Emerg Infect Dis. 2026;32:169-179. PubMed           Abstract available Int J Infect Dis MA Q, Yao L, Ding H, Tian W, et al SARS-CoV-2 Variant Specific Protective Immunity and Long-term Immune Recovery in People Living With HIV: A Retrospective Cohort Study. Int J Infect Dis. 2026 Feb 16:108491. doi: 10.1016/j.ijid.2026.108491. PubMed           Abstract available J Med Virol EXPRESSION OF CONCERN: Resistance-As...

#Influenza and Other Respiratory Viruses Research #References (by AMEDEO, Feb. 21 '26)

  Antiviral Res WRONSKI S, Obernolte H, Schaudien D, Braun A, et al Prophylactic intranasal administration of bacterial lysate OM-85 mitigates human rhinovirus (RV-A1b) lung infection and inflammation in mice. Antiviral Res. 2026;247:106362. PubMed           Abstract available HEDSKOG C, Rodriguez L, Hu Y, Li J, et al SARS-CoV-2 Resistance Analyses From the Phase 3 BIRCH Study of Obeldesivir in High-Risk Nonhospitalized Participants With COVID-19. Antiviral Res. 2026 Jan 19:106351. doi: 10.1016/j.antiviral.2026.106351. PubMed           Abstract available RODRIGUEZ L, Hu Y, Li J, Han D, et al SARS-CoV-2 Resistance Analyses From the Phase 3 OAKTREE Study of Obeldesivir in Low-Risk Nonhospitalized Participants With COVID-19. Antiviral Res. 2025 Dec 29:106339. doi: 10.1016/j.antiviral.2025.106339. PubMed           Abstract available Arch Virol LIM KS, Selvan ME, Ea CK...

Amino acid #mutations K54E and S154P in the #neuraminidase attenuate #H3N2 #canine #influenza virus in mice

  ABSTRACT Dogs are considered mixing vessels for influenza viruses , posing a pandemic potential via viral reassortment . Our previous studies indicated that the avian-origin H3N2 canine influenza virus (A/canine/Zhejiang/1/2010, abbreviated C1) is virulent in canine and mice . Furthermore, we found that the HA and NA genes of C1 share a close genetic relationship with an H3N2 avian influenza virus (A/duck/Shanghai/06/2009, abbreviated D6), but they exhibit distinct pathogenicity . However, the understanding mechanisms remain unclear. In the present study, we explored the genetic determinants that contribute to the different pathogenicity between the C1 and D6. By using the reverse genetics approaches, we rescued several single-gene and position-substituted reassortant viruses based on the C1. The replication in Madin–Darby canine kidney cells and pathogenic trial in mice showed that the neuraminidase (NA) gene played a critical role in C1 virulence. Further analysis demonstrated ...

History of Mass Transportation: A First-generation GTEL and a 1923 electric auto in Fremont, Nebraska in 1953

By Union Pacific Railroad - eBay itemphoto frontphoto back, Public Domain,  https://commons.wikimedia.org/w/index.php?curid=22868545 Source:  Link:  https://en.wikipedia.org/wiki/Gas-turbine_locomotive ____

#USA, #Wastewater Data for Avian #Influenza #H5 (CDC, Feb. 20 '26)

  {Excerpt} Time Period: February 08, 2026 - February 14, 2026 -- H5 Detection :  9 site(s) ( 1.9% ) -- No Detection :  466 site(s) ( 98.1% ) -- No samples in last week :  171 site(s) The H5 detections at sewershed IDs 809 and 912 in Michigan are false detections resulting from a data error. These will be corrected in the next update. (...) Source:  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

  Poultry farms in Andhra Pradesh State. Source:  Link:  https://wahis.woah.org/#/in-review/7268 ____