The mammalian-adaptive PB2-E627K substitution preserves viral fitness of clade 2.3.4.4b H5N1 HPAIV in birds.
Elizabeth Billington, Sofia Riccio, Maryn D. Brown, Benjamin C. Mollett, Jessica L. Quantrill, Simon Johnson, Cecilia Di Genova, Jiayun Yang, Jean-Rémy Sadeyen, Audra-Lynne D. Schlachter, Kelly J. Roper, Jafar Hassan, Benjamin Clifton, Kajal Ralh, Caroline Janet Warren, , Joe James
This study shows that the mammalian-adaptive PB2-E627K mutation in H5N1 HPAIV maintains viral fitness in avian hosts, increasing zoonotic risk.
bioRxiv · Oct 8, 2026 · PreprintMicrobiology