The CIA has ended the use of vaccine programmes in its spying operations amid concerns for the safety of health workers, the White House has said.
In a letter to US public health schools, a White House aide said the CIA stopped such practices in August.
The CIA reportedly used a fake vaccine programme in its effort to learn the whereabouts of Osama Bin Laden.
The CIA’s move comes after deadly attacks by militants on polio vaccination workers in Pakistan.
Even though the country is suffering a grave resurgence of the disease, more than 60 polio workers and security personnel were killed between December 2012 and April 2014, most of them in the Khyber Pakhtunkhwa province, according to Pakistani officials and humanitarian workers.
Sixty-six cases of polio have been declared in Pakistan since January, compared with only eight during the same period last year.
The geographical spread of the cases suggests they are mostly sourced to the north-western Waziristan tribal region, the BBC’s Ilyas Khan reports from Islamabad. Militants controlling the region banned vaccination there, saying health workers may include American spies.
The World Health Organization and the UN’s agency for children have issued a statement saying they appreciated the US government’s commitment.
In a letter dated 16 May, the White House assistant to the president for homeland security and counter-terrorism, Lisa Monaco, wrote that CIA director John Brennan had directed the agency to cease “operational use of vaccine programmes”.
“Similarly, the agency will not seek to obtain or exploit DNA or other genetic material acquired through such programmes,” she wrote, adding the policy applied worldwide to US and non-US persons alike.
Genetic material obtained through a fake door-to-door hepatitis B vaccination programme reportedly helped the CIA confirm Bin Laden’s whereabouts in the Pakistani city of Abbottabad.
BBC has the full article