The hemagglutinin E190D substitution in clade 2.3.4.4b A(H5N1) influenza virus reduces receptor binding and viral fitness
The detection of a clade 2.3.4.4b influenza A(H5N1) variant bearing an HA-E190D substitution in an infected human raises concerns regarding mammalian adaptation. We systematically evaluated the impact of the HA-E190D substitution in the A/British Columbia/PHL-2032/2024 (BC/24) virus on receptor binding specificity and viral fitness in vitro and in vivo.