The biggest challenge for vaccine workers in Pakistan? Staying alive.

In 2019, Wajid Ali Mohmand, a front-line health worker in his 30s, was doing his part in a nationwide campaign in Pakistan to eradicate polio, a disease that can permanently paralyze children if they are not vaccinated.

Pakistan and Afghanistan are the only two countries in the world where the disease is endemic.

Related: France launches citizens’ collective to tackle widespread vaccine hesitancy

Syed Feroz Shah, a health worker in the Federally Administered Tribal Areas (FATA) of northwestern Pakistan, said his cousin, Wajid Ali, was shot fatally by a man who did not want his daughter to receive the polio vaccine.

“[The man had,] I think, some fear in his mind about the polio vaccination. That’s why Mr. Wajid tried his best to convince him.”

The man had, “I think, some fear in his mind about the polio vaccination,” Shah recalled. “That’s why Mr. Wajid tried his best to convince him.”

Now, as Pakistan ramps up its COVID-19 vaccination campaign that began last month with a donation of 500,000 doses of the Sinopharm vaccine from China, the country faces the challenge of quelling vaccine fears. And Shah and others worry about the safety of health workers whose lives are on the line every day.

At least 100 health workers and their security guards have been killed in Pakistan since 2012.

Related: Wary of coronavirus vaccines, some Chinese citizens are ‘opting out’ 

Observers say that reasons for hostilities toward vaccine workers in the country vary wildly, but that misinformation, hard-line religious views and a 2011 CIA operation targeting Osama bin Laden have played an outsized role.

The government has taken some steps to encourage people to get the vaccine.

Pakistan’s prime minister, Imran Khan, publicly thanked China for the vaccine donation in a televised event in February. The government also launched a campaign underscoring the importance of vaccines; it enlisted the help of sports stars, actors and religious leaders to spread the message.

But some wonder if it will be enough.

A January Gallup survey showed that out of a thousand people polled in Pakistan, almost half said they would not get vaccinated against COVID-19. 

The struggle for government support

Shah remembers his cousin, Wajid Ali, as someone who believed in negotiation and communication.

“Besides my cousin, he was my best friend,” Shah said in an interview from the FATA.

Related: Ghana receives first vaccines from COVAX

Wajid Ali was someone who’d strike up a conversation with a stranger. He got to know everyone, and he was a good listener. That’s why he was so good at his job, Shah said.

One spring day in 2019, Wajid Ali came face-to-face with a father who had repeatedly refused to have his daughter vaccinated.

Shah said that he made it clear to the father that if he refused again, he would have to report him to health officials.

Their conversation took a wrong turn, and the father shot Wajid Ali twice, according to Shah. He died shortly after, leaving behind 10-month-old twins and his wife. His killer remains on the run.

“Mr. Wajat Ali sacrificed his life while he was saving the lives of the children of the nation.”

“Mr. Wajat Ali sacrificed his life while he was saving the lives of the children of the nation,” Shah said.

The World Health Organization condemned his killing, but Shah said the family has struggled to get government support for Wajid Ali’s widow and children. He said his widow wants to take a job as a teacher but so far has been unsuccessful.

He hopes that the government takes more steps to support the families of the vaccine workers who were killed and to make sure that the ones working in the field are safe.

The role of a CIA operation

Misinformation has played a big role in vaccine skepticism in Pakistan.

The same month that Wajid Ali was killed in Pakistan — April 2019 — angry protesters set fire to a clinic in the city of Peshawar in response to videos from a local schoolteacher falsely claiming that polio vaccines made children sick.

Related: Dual citizens in Mexico seek vaccine options in the US as rollout lags

People were so outraged that health officials decided to suspend the vaccination drive.

Monica Martinez-Bravo, a researcher with the Center for Monetary and Financial Studies in Madrid, conducted a study that found that details around the CIA operation to kill Osama bin Laden had been manipulated to perpetuate anti-vaccine propaganda.

“The story [goes] back to 2011, when the CIA got a piece of information suggesting that Osama bin Laden might be hiding in a particular compound in Abbottabad, Pakistan,” she said.

During the planning phase of its mission, she said, the CIA wanted to ensure that bin Laden was, in fact, in the compound. (Ultimately, SEAL Team Six was credited for taking out bin Laden.)

Martinez said agents enlisted the help of a Pakistani vaccine worker to get DNA samples from the kids living there — “to compare them to the DNA of bin Laden’s sister and then figure out if the children were related to bin Laden, which would have been telling proof that indeed bin Laden was hiding there.”

The US already had his sister’s DNA because she died in a hospital in Boston. In 2011, The Guardian published a story about the CIA program revealing the vaccine worker’s involvement. Pakistanis were furious.

“You know, they were essentially saying, ‘Do not trust health workers. They might be spies or they might want to harm your children.’”

In her study six years later, Martinez discovered that the Pakistani Taliban used this in its anti-vaccine propaganda: “You know, they were essentially saying, ‘Do not trust health workers. They might be spies or they might want to harm your children.’”

Health experts around the world were outraged by the CIA raid, too. Deans of 12 American schools of public health sent a letter to US President Barack Obama in protest.

The CIA said it would no longer use health workers as part of its operations.

But experts say the damage was done.

“People who work in health, or public health especially, work with the trust of the local populations and once that trust is broken, it’s very difficult and it takes time to get this trust back,” said Dr. Rana Jawad Asghar, a leading Pakistani epidemiologist.

“I think all the nations should sign a charter under maybe [the] United Nations or [the] World Health Organization to never use health systems or health professionals for any other activity which is not related to health,” Asghar said.