ETIDIOH - NEW

  Abstract Ongoing transmission of influenza A virus (H5N1) in U.S. dairy cattle threatens both animal and human health , underscoring the need to understand the durability of host immunity against reinfection with evolving genotypes . We challenged naive and convalescent cows , infected one year prior with H5N1 genotype B3.13, with either homologous B3.13 or heterologous D1.1 genotype virus . Homologous rechallenge resulted in complete clinical protection with no infectious viral shedding . Conversely, heterologous rechallenge led to transient clinical disease and limited infectious viral shedding . Convalescent cows experienced significantly milder disease than naive cows, which developed severe illness with high viral shedding and required early euthanasia , regardless of the strain. These findings indicate that naturally acquired immunity offers strong protection against severe illness but may allow silent transmission of divergent strains . Therefore, natural herd immunity alo...

  ABSTRACT Monoclonal antibodies represent potent biological countermeasures against a wide range of human diseases ; however, their clinical application and widespread use are limited by the high cost and complexity of antibody production and manufacturing. The mRNA-lipid nanoparticle (mRNA-LNP) platform offers a versatile strategy for vaccine development and protein-replacement therapies. Since the COVID-19 pandemic, a number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)- neutralizing antibodies have been identified, with several granted emergency use authorization for patients. Here, we report the design and generation of mRNA-LNPs encoding two SARS-CoV-2-neutralizing antibodies , 76E1 and LY1404, which, respectively, target the spike protein’s fusion peptide (FP) and receptor-binding domain (RBD). We demonstrated that a single intramuscular administration of these mRNA-LNPs in mice resulted in robust antibody production that sustained in circulation for 7–14 d...

  ABSTRACT Accurate antigenic characterization of influenza viruses is critical for vaccine strain selection but is often confounded by intrahost genetic diversity and culture-induced adaptations . We analyzed 60 A(H3N2)-positive nasopharyngeal specimens collected during the 2017–2018 influenza season to determine how virus propagation in MDCK cells affects viral genetic and antigenic properties . Deep sequencing revealed frequent genome-wide intrahost polymorphisms , including amino acid variants within major hemagglutinin (HA) antibody-binding sites . Virus propagation imposed rapid purifying selection, markedly reducing intrahost genetic diversity . Serological analyses demonstrated that these selective events altered antigenic properties, indicating that culture adaptation can alter antigenic profiles . To assess the functional impact of HA polymorphisms, we generated mixed viral populations containing defined ratios of HA-160K, HA-160T, and HA-160I variants identified in clini...

  {Scotland} A small commercial poultry premise. Samples taken were positive for HPAI H5N1. Birds presented clinical signs prior to testing. Source:  Link:  https://wahis.woah.org/#/in-review/7173 ____