Using chick embryos as an example, the virus is grown in different embryos in a series.

以鸡胚为例， 病毒在一系列不同的胚胎中生长。

Some of the most common methods involve passing the disease-causing virus through a series of cell cultures or animal embryos (typically chick embryos).

一些最常见的方法涉及将致病病毒通过一系列细胞培养物或动物胚胎（通常是鸡胚）。