Short Scientific Report: Global Evolutionary and Epidemiological Trends Across H5Nx Influenza A Viruses

We present a comprehensive analysis of 166,501 complete H5Nx influenza A virus genomes from NCBI, spanning subtypes H5N1-H5N9. Using local bioinformatics pipelines, we extracted temporal, geographic, and codon usage metadata to reveal evolutionary pressures, host adaptation patterns, and spatiotemporal emergence dynamics across subtypes. Key findings include strong avian codon adaptation in H5N1, increasing sequence sampling post-2020, and subtype-specific codon bias signatures.