VOA慢速英语:Is There a Deadly Polio Virus Hiding Somewhere?

paralyze - v. to make (a person or animal) unable to move or feel all or part of the body

mutate – v. biology to cause (a gene) to change and create an unusual characteristic in a plant or animal : to cause mutation in (a gene)

vaccine - n. a substance that is usually injected into a person or animal to protect against a disease

antibodies - n. a blood protein produced to fight a specific antigen

devastating - adj. highly destructive or damaging