A Pakistani schoolgirl, who was displaced with her family from Pakistan's tribal areas due to fighting between militants and the army, receives a polio vaccine from a health worker, while other children wait their turn, at their school in a poor neighborhood on the outskirts of Islamabad, Pakistan, Thursday, Jan. 31, 2013. A roadside bomb killed two Pakistani polio workers on their way to vaccinate children in a northwestern tribal region near the Afghan border on Thursday, an official said. (AP Photo/Muhammed Muheisen), APTOPIX