Sino Biological offers recombinant flu antigen products under its ProVir™ viral antigen collection. The product line covers HA, NA, and NP proteins, from all WHO-recommended vaccine strains in recent years. These antigens can be used to analyze vaccine-induced antibody response. In addition, Sino Biological also develops a large collection of monoclonal antibodies against the flu antigens. These reagents can help facilitate relevant assay development.