A top White House official has assured the deans of prominent U.S. public health schools that the CIA will no longer use vaccination programs as cover for spying operations. The agency used the ruse in targeting Osama bin Laden before the U.S. raid that killed him in 2011.

Lisa Monaco, President Barack Obama’s top counterterrorism adviser, wrote to the deans of 13 public health schools last week, saying that the CIA has agreed it would no longer use vaccination programs or workers for intelligence purposes. The agency also agreed to not use genetic materials obtained through such programs.

A Pakistani doctor, Shakil Afridi, provided polio vaccinations in the Pakistani city of Abbottabad as cover for his CIA-backed effort to obtain DNA samples from children at a compound where bin Laden was later killed during a 2011 raid. Afridi was convicted and sentenced by a Pakistani court to 33 years in prison for treason. The sentence was later overturned and Afridi faces a retrial.

The health school deans were among a group of medical authorities who publicly criticized the CIA’s use of the vaccination program after it was disclosed by media accounts and Pakistan’s arrest of Afridi as a CIA operative.

In her May 16 letter to the health school deans, Monaco said that the U.S. “strongly supports the Global Polio Eradication Initiative and efforts to end the spread of the polio virus forever.”

She added that CIA Director John Brennan committed in August 2013 that the agency would “make no operational use of vaccination programs, which includes vaccination workers.” Also saying no DNA or genetic material would be used from such programs, Monaco said the CIA policy “applied worldwide and to U.S. and non-U.S. persons alike.”

CIA spokesman Dean Boyd said Brennan “took seriously the concerns raised by the public health community, examined them closely, and took decisive action.”

Monaco’s letter was first disclosed in a report by Yahoo News.

Monaco’s letter came days after Pakistan acted to quell a growing polio crisis within its borders. The public health deans had warned last year that the CIA’s use of a vaccination program had played a role in the shootings of several health workers in Pakistan and could hamper anti-polio efforts.

“Public health programs should not be used as cover for covert operations,” they said.

Last week, Pakistan’s Health Ministry announced that it would require that all travelers leaving the country first get a polio vaccination. That move followed the World Health Organization’s declaration earlier this month that polio’s spread was an international public health emergency. The WHO identified Pakistan, Syria and Cameroon as nations that had allowed polio to spread beyond their borders.

Pakistan was the only country with reported endemic polio that saw a rise in new cases in 2012, the health organization reported. Pakistan accounted for more than a fifth of all polio cases identified across the world in 2013.

The CIA’s use of a polio vaccine program to spy on bin Laden’s compound undercut Obama’s own high-profile speech to the Muslim world in 2009, in which he touted U.S. efforts to slash the growth of polio in Pakistan, Afghanistan and Nigeria. With Obama administration assurances, Muslim scholars in two international groups issued religious decrees urging parents to vaccinate their children

(AP)