At least nine medical workers have been killed in a series of attacks on a polio vaccination effort in Pakistan. Three people were killed earlier today near the city of Peshawar, one day after six workers, all female, were killed in Peshawar and Karachi. The shootings are believed to be a part of a militant campaign against polio eradication in response to the CIA-backed fake vaccination program in Pakistan that helped locate Osama bin Laden. Taliban warlords announced a ban on immunization efforts earlier this year, calling them a cover for espionage. Pakistan is one of three countries in the world where polio remains a large-scale risk.