PAKISTAN
ASIF HASSAN/AFP/GETTY
Karachi, Pakistan— Policemen stand guard as a health worker administers polio drops to a child during a vaccination campaign on April 21, a day after eight gunmen on motorcycles shot dead seven policemen protecting vaccination workers. Islamist militants have repeatedly targeted such programs, claiming they are a Western conspiracy to sterilize Pakistani children. Nearly 80 health workers have been killed since December 2012. Jamaat-ul-Ahrar, a splinter group of the Pakistani Taliban, claimed responsibility for the April 20 attack. Pakistan is one of only two countries, along with Afghanistan, where polio remains endemic.