activity immunity

• 主动免疫

activity immunity的用法和样例：

例句

1. Influenza may be prevented by active immunization with a polyvalent killed or subunit vaccine.
   可以通过主动免疫接种多价灭活疫苗或亚单位疫苗预防流感。
2. Although passive immunization now seems to hold the most promise, active immunization is not out of the running.
   虽然目前看来是被动免疫最具潜力，但是主动免疫也不见得就此退出赛局。