A polio worker administers polio vaccine to a child during a vaccination campaign in Rawalpindi
A polio worker administers polio vaccine to a child, who arrived from the Khyber-Pakhtunkhwa province, during a vaccination campaign at a bus stop in Rawalpindi May 13, 2014. Pakistan's failure to stem the spread of polio triggered global emergency health measures, with the World Health Organization (WHO) recommending all residents must show proof of vaccination before they can leave the country.
REUTERS/Sara Farid (PAKISTAN - Tags: HEALTH)