n.牛痘接种员，种痘刀
At present, no widely approved vaccine exists for malaria.
目前，还没有被广泛认可的疟疾疫苗。
Seven million doses of vaccine are annually given to British children.
英国孩子每年要接种7百万剂疫苗。
Roll on the day someone develops an effective vaccine against malaria.
盼望有一天有人会研制出一种能有效预防疟疾的疫苗。