Hemagglutinin (ha) is the most important surface antigen of virus and has subtype speciality, which induce the peculiar antibody.
血凝素(A)蛋白为病毒最重要的表面抗原，具有亚型特异性，同时可以诱导特异性抗体的产生。
2
Primary immunogenicity end points were the rates of 4-fold or greater increases in serum hemagglutinin inhibition antibody to each of the 3 vaccine strains before and 28 days after inoculation.