And the same is true for the real hemagglutinin.

真正血凝素也是如此。

To understand how this works, think of hemagglutinin as a bust of 19th century French Emperor Napoleon Bonaparte.

要了解其工作原理，请将血凝素想 19 纪法国皇帝拿破仑·波拿巴半身像。

On the inside is the virus' RNA, and on the outside are lots and lots of hemagglutinin proteins.

里面是病毒RNA，外面是多多血凝素蛋白。

The human flu virus could pick up a bird flu hemagglutinin that's never infected humans before.

人类感病毒可以吸收以前从未感染过人类感血凝素。

And type A's can be divided into further sub-categories, depending on the subtypes of two proteins present on their surface: hemagglutinin, 'H', and neuraminidase, 'N'.

A型感病毒还可以进一步细分，取决于其表面存在两种蛋白质亚型：血凝素(H)和神经氨酸苷酶(N)。

There are key parts of hemagglutinin that haven't changed much over time and are probably critical to infect human cells; these " conserved regions" could be promising targets for universal vaccines.

血凝素一些关键部分随时间变化不大，可能对感染人体细胞至关重要；这些“保护区”可能为通用疫苗有前途目标。