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）蛋白质在禽播中所起作用而。

“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，血凝素和神氨酸苷酶，这两种成分使得病毒可以入侵宿主身体细胞。