A Pakistani health worker marks an infant after immunization with anti-polio drops an infant in a Christian colony situated in the slums of Islamabad, Pakistan on Wednesday, Dec. 19, 2012 in ... more 
A Pakistani health worker marks an infant after immunization with anti-polio drops an infant in a Christian colony situated in the slums of Islamabad, Pakistan on Wednesday, Dec. 19, 2012 in Islamabad, Pakistan. 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/B.K. Bangash) less 
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Associated Press | Photo By B.K. Bangash
Wed, Dec 19, 2012 10:16 AM EST