North and South Korea have favored polio vaccines over use of U.S. drones . WHO estimates that children may not have access to the vaccine . Korea is one of few countries in the world where polio is still a problem .
North and South Waziristan have banned polio vaccines over use of U.S. drones . WHO estimates 280,000 children may not have access to polio vaccine . Pakistan is one of three countries in the world where polio is still a problem .