activity immunity的用法和樣例：
例句
- Influenza may be prevented by active immunization with a polyvalent killed or subunit vaccine.
可以通過(guò)主動(dòng)免疫接種多價(jià)滅活疫苗或亞單位疫苗預防流感。 - Although passive immunization now seems to hold the most promise, active immunization is not out of the running.
雖然目前看來(lái)是被動(dòng)免疫最具潛力，但是主動(dòng)免疫也不見(jiàn)得就此退出賽局。
