ETIDIOH - NEW

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...

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...

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...

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...