A vaccine is a substance containing a harmless form of the germs that cause a particular disease. It is given to people, usually by injection, to prevent them from getting that disease.
双语例句
例： Anti-malarial vaccines are now undergoing trials.
抗疟疾疫苗正处在试验阶段。
例： Seven million doses of vaccine are annually given to British children.
英国儿童每年接种700万剂疫苗。
例： people who normally receive the flu vaccine.
常规接种流感疫苗者。