In addition, the immunity produced so far lasts only three to six months, so frequent vaccinations would be necessary . 再则，至此产生的免疫只能持续三至六个月,因此需要经常种痘。
The research for a sort of sars epidemic dynamical system 一类带有种痘年龄的流行病模型
A preliminary study of vaccination in jiangnan during the qing dynasty 清代江南种痘事业探论
For things like vaccinations , checkups , dental visits , and more ，可用于种痘定期检查牙医检查及其他的保健用途。
Vaccination campaigns have controlled the disease in western countries 种痘运动在西方国家已经很好的控制了这种疾病。
Induced by vaccination 因种痘引起的
Measles is the leading cause of vaccine - preventable death in children （作业句）麻疹是导致孩子死亡的罪魁祸首，这种病是可通过种痘预防的。
Please have your passport , health certificate and vaccination certificate ready . they ' ll be inspected 请将您的护照、健康证书和种痘证书准备好，已被检查。
No inoculations or vaccinations are required unless coming from or passing through an infected area 除非您是经过或从传染区域而至，否则预防和种痘是不需要的。
The world health organization says vaccination campaigns in more than forty countries in africa have saved one million children 世界卫生组织说在非洲四十多个国家进行的种痘运动已经挽救了一百万个孩子。
