In 2011, the CIA used a hepatitis vaccination program to help locate Al Qaeda leader Osama bin Laden.
A local doctor running an immunisation program, Dr Shakil Afridi, visited the Abbottabad compound where bin Laden was located just weeks before US Special Forces killed the terrorist leader.
Dr Afridi was after DNA from children in the compound and is believed to have given US intelligence agents material that he obtained during the vaccination drive. It is not known if any of his actions played a direct role in bin Laden's capture.
Islamist groups were outraged when news of the program emerged and attacks on immunisation workers increased across the country.
Dr Abid says the CIA operation to capture bin Laden had a negative effect on his work.
"At the time it was really bad for all our immunisation programs," Dr Abid said.