Primary immunogenicity end points were the rates of 4-fold or greater increases in serum hemagglutinin inhibition antibody to each of the 3 accine strains before and 28 days after inoculation.

• 基本的免疫原性滴定终点可以4倍或者更大的对在3种疫苗品系接种之前和接种后28天增加血清血凝素抑制剂抗体。