has role protective antigen role protective antigen Influenza virus protein HA from Influenza A virus (A/chicken/Indonesia/7/2003(H5N1)) Protegen ID: 550; NCBI Protein GI: 129282887; NCBITaxon: 430432 Allen Xiang protein Oliver He All specific-pathogen-free chickens immunized with (vFP2211) expressing a modified synthetic HA gene from H5N1 A/chicken/Indonesia/7/2003 were clinically protected from HPAI challenge [PubMed: 20521642].