Antigenic characterization of low and highly pathogenic H5 avian influenza viruses using antigenic cartography

H5 and H7 subtype of low pathogenic avian influenza (LPAI) viruses could evolve into highly pathogenic avian influenza (HPAI) viruses in poultry and could cause severe outbreaks. The antigenicity of the viruses is a core component to develop vaccines and antibody therapies. Thus, in this study, we analyzed the antigenicity of the H5 subtype of 10 LPAI and 4 HPAI viruses. While the LPAI viruses showed highly similar antigenicity, the HPAI viruses showed relatively higher antigenic variability. The results highlight that the LPAI viruses’ antigenicity has not been mutated in their natural host, wild birds. Further, the study suggested that the vaccination could accelerate the mutation of the H5 HPAI viruses’ antigenicity. Continuous monitoring of the antigenicity changes is needed to control future outbreaks.