Last dose of polio vaccine is at the age of______A. 2-4 yearsB. 3-6 yearsC. 4-6 yearsD. 5-7 years 0 0 votesArticle Rating Subscribe LoginNotify of new follow-up commentsnew replies to my comments Label {} [+] Name* Email* Website Label {} [+] Name* Email* Website 0 Comments Oldest Newest Most Voted Inline FeedbacksView all comments