A Pakistani health worker, right, gives a polio vaccine to a child, who was displaced with his family from Pakistan's tribal areas due to fighting between the Taliban and the army, in a poor neighborhood that hosts people displaced from tribal areas and Afghan refugees, on the outskirts of Islamabad, Pakistan, Wednesday, Jan. 22, 2014. Militants oppose vaccination against polio and consider such campaigns a cover for spying and also claim the vaccine is intended to make Muslim boys sterile. (AP Photo/Muhammed Muheisen)