Last dose of polio vaccine is at the age of______ A. 2-4 years B. 3-6 years C. 4-6 years D. 5-7 years 0 0 votes Article Rating Subscribe Login Notify of new follow-up comments new replies to my comments Label {} [+] Name* Email* Label {} [+] Name* Email* 0 Comments Oldest Newest Most Voted Inline Feedbacks View all comments