VOA慢速英语:两家制药公司将开发针对新冠变种病毒的疫苗

variant – n. something that is different in some way from others of the same kind

dose – n. the amount of a medicine, drug, or vitamin that is taken at one time

spike protein – n. a kind of protein that protrudes from some viruses

advance – v. to move forward

accelerate – v. to move faster : to gain speed