Dr Kawaoka was interested in the role a protein called haemagglutinin (HA) plays in the transmission of avian influenza.

河冈义裕对一种叫做血凝素（HA）的蛋白质在禽流感传播中所起的作用而感兴趣。

“H7” and “N9” refer to particular types of two proteins, haemagglutinin and neuraminidase, that help influenza viruses invade host cells.

“H7”和“N9”是指两种蛋白质，血凝素和神经氨酸苷酶，这两种成分使得流感病毒可以入侵宿主身体细胞。