Opposition to the vaccination programme has been driven by conservative clerics who claim it is a plot to sterilise Muslim children, and Taliban commanders who fear it is being used to gather intelligence in their strongholds. Those fears increased following the 2011 killing of al-Qaeda leader Osama bin Laden in Abbottabad where Pakistani doctor Shakil Afridi was arrested for running a fake hepatitis vaccination campaign to help the CIA collect DNA samples of members of the bin Laden family.