December 19, 2012 - 12:33 PM
A Pakistani injured polio worker is treated at a local hospital in Peshawar, Pakistan on Wednesday, Dec. 19, 2012. Gunmen shot dead a woman working on U.N.-backed polio vaccination efforts and her driver in northwestern Pakistan, officials said, just a day after similar attacks across the country killed several female polio workers. (AP Photo/Mohammad Sajjad)