Senior Pakistani health officials have welcomed a move by US intelligence agencies to stop using immunisation programs as a cover for their operations.
But the move comes amid a resurgence of polio cases in Pakistan, a country once thought to be on the verge of eradicating the deadly disease.
"It is good news. If they stick to it then it will help with convincing people that vaccines are not part of a conspiracy," Dr Nima Abid, a senior official with the World Health Organisation in Islamabad, said.
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.
"It hurt us a lot. Health programs should never be used as a front for intelligence agencies. It undoes all our work and puts our people at risk."
There has long been suspicion among extremist groups that vaccines for diseases such as polio and measles, mumps and rubella are a Western conspiracy to sterilise Muslims.
Prior to bin Laden's capture, extremist groups actively discouraged vaccinations. But after it, they began to seriously target inoculators.
Dozens have been killed and large parts of the country's north-western tribal areas are no-go zones for vaccination programs.
Hundreds of thousands of children have gone unvaccinated there since 2011.
Polio has since made a big comeback across Pakistan as a result.
This year there have been more than 60 confirmed cases of the disease, most stemming from the tribal areas. This time last year the number was eight.
"Polio has been generally rising in Pakistan because the Taliban and some religious clerics claim that polio vaccinations are actually a secret attempt to sterilise the population." Mustafa Qadri, an analyst at Amnesty International, said.
Polio is a viral disease spread by faecal matter often through open sewers and drains. It can cause serious paralysis and in some cases death.
Polio an international public health emergency: WHO
As recently as 25 years ago, Pakistan recorded thousands of cases of polio.
By 2012 a comprehensive vaccination program had seen the number of infections drop dramatically; Pakistan was on track to eradicate the disease.
That has all changed now. Pakistan is now one of the three remaining countries where the disease is endemic – the others are Nigeria and Afghanistan.
"To be thought of as the world's reservoir of polio? It's not a good title to have," Dr Abid said.
The situation is so bad that earlier this month the World Health Organisation declared the spread of polio to be an international public health emergency.
The WHO has recommended travel restrictions for Pakistanis and says they should provide an immunisation certificate when they arrive in other countries.
Many countries, such as India, have adopted these recommendations in regards to Pakistan.
Pakistan is also trying to clamp down on travel within its own borders – requiring those travelling from the north-west of the country also carry proof that they've been inoculated.
But millions of Pakistanis migrate internally every year and preventing the spread of polio is a tough task.
Many end up in Pakistan's largest city, Karachi.
Naseem Munir, who was recently killed in a domestic violence incident, was on the frontline in the war to beat polio in Pakistan.
"I do this work because it is important. For the health of children and to protect them from disability, as if a child becomes paralysed, the entire family is affected," she said.
Munir was a lady health care worker - one of tens of thousands of women getting paid only a few dollars-a-day to administer polio vaccinations to children - and knew the reality of the dangers she and her colleagues faced.
She remained passionate and committed to her work despite losing three of her colleagues in a fatal drive-by attack in January.
"I am not nervous. I am happy to go to endangered areas. I am not afraid of anything. I am a soldier," she said.
Dozens of heavily armed policemen would accompany Munir and her to team to the Karachi suburb of Landhi Town - an area known to be a centre for the Taliban.
The vaccinators go door-to-door asking those inside if they have any children under the age of 5. If so, drops are administered.
But some parents refuse. They often do so because of a concerted propaganda campaign by Islamic extremists that tells them the drops contain urine and other poisons.
Huge spike in cases of polio in Pakistan
At Karachi's National Institute of Child Health, doctors are alarmed at the re-emergence of polio.
Dr Jameel Raza says he has noticed a huge spike in cases, especially in the past year.
"Sometimes you are able to help them out with braces and rehabilitation programs to make them walk." Dr Raza says.
"Of course the more severe cases it is not possible to make them walk and they remain severely disabled."
The Pakistani government has put a big effort into stopping the disease.
It has also enlisted the help of prominent Islamic clerics such as Mufti Naeem who runs the Binoria Madrassa in Karachi.
"Look, I am openly saying that these polio drops are not bad for Islam and Muslims," Mr Naeem says.
"These extremists who are doing this, who are killing polio people, they are doing wrong."
But Mr Naeem says the use of an immunisation drive by the CIA as a cover has fuelled conspiracy theories about vaccinations.
The news that American intelligence agencies will not be using immunisation programs as cover will help convince some people, according to Dr Abid.
But he is far from certain it will solve the problem of resistance to vaccinations.
"Public health campaigns should not be used for any other reason than to help people. What has happened is an example what can happen when they are used in the wrong way," he said.
"I hope the damage can be repaired."
- Australian Broadcasting Corporation
- © ABC