ETIDIOH - NEW

At a glance -- The Influenza Risk Assessment Tool (IRAT) is a CDC evaluation tool developed with assistance from global animal and human health influenza experts. -- The IRAT is used to assess the potential pandemic risk of influenza A viruses that are not currently circulating in people. -- This latest IRAT assessed two recent clade 2.3.4.4b avian influenza A(H5N1) viruses: A/California/147/2024 and A/Washington/239/2024. -- These viruses scored in the "moderate risk" category for potential emergence and public health impact , similar to previous assessments of earlier clade 2.3.4.4b avian influenza A(H5N1) viruses. These results validate the proactive, coordinated U.S. government response. -- The IRAT does not assess the immediate risk to the public's health, which is unchanged and remains low, and it does not predict future pandemics. Purpose The IRAT uses expert opinion to evaluate the potential of a representative novel influenza A virus to gain the ability for perso...

{Excerpt} Time Period: April 20, 2025 - April 26, 2025 - H5 Detection :  5 sites ( 1.2% ) - No Detection :  402 sites ( 98.8% ) - No samples in last week :  91 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html ____

Abstract Highly pathogenic avian influenza (HPAI) clade 2.3.4.4b H5N1 is circulating widely in lactating cows in the United States . Due to the critical need for intervention strategies for this outbreak, we evaluated antibody and cellular immune responses of a clade 2.3.4.4b H5 mRNA-LNP vaccine in calves . We found that the H5 mRNA-LNP vaccine induced a robust antibody and CD8+ T cellular-mediated immune response and conferred protection against clade 2.3.4.4b H5N1 infection. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.05.01.651548v1 ____

Abstract Highly pathogenic avian influenza (HPAI) represents a threat to animal and human health , with the ongoing H5N1 outbreak within the H5 2.3.4.4b clade being the largest on record. However, it remains unclear what factors have contributed to its intercontinental spread . We use Bayesian additive regression trees, a machine learning method designed for probabilistic modelling of complex nonlinear phenomena, to construct species distribution models (SDMs) for HPAI clade 2.3.4.4b presence. We identify factors driving geospatial patterns of infection and project risk distributions across Europe . Our models are time-stratified to capture both seasonal changes in risk and shifts in epidemiology associated with the succession of H5N6/H5N8 by H5N1 within the clade . While previous studies aimed to model HPAI presence from physical geography, we explicitly consider wild bird ecology by including estimates of bird species richness, abundance of specific taxa, and "abundance indices...