This week's killings highlighted the vulnerability of polio vaccination workers in Pakistan. Credit: GPEI

The assassination of polio vaccination workers in Pakistan this week could be a “game changer” in global efforts to eradicate the disease, say public health experts.

Between Monday and Wednesday gunmen killed nine health workers in Karachi, the country's largest city, and the northwest province of Khyber Pakhtunkhwa. Two more workers were injured. The victims, mostly women, were part of an immunisation campaign in which local workers trek door-to-door vaccinating young children against polio virus. No one has claimed responsibility for the attacks, but militants linked to the Taliban are suspected.

In response to the coordinated violence, the Pakistani government partially suspended a three-day vaccination campaign that focused on the country’s remaining polio hotspots, and which was being led by the Global Polio Eradication Initiative (GPEI), a coalition of governmental and non-governmental organisations. The United Nations, which supports efforts through the GPEI, pulled its support staff from the field over safety concerns.

“This is a major incident that will make us think of where we go from here,” says Elias Durry, Emergency Coordinator for Polio, at the World Health Organization (WHO) in Islamabad.

Another government-run vaccination campaign is scheduled for mid-January. Successful campaigns are essential over the dry season of the next three months, says Durry, because that is when the virus spreads less effectively, thus offering a chance at stamping it out from its remaining strongholds. “I am 100 percent sure vaccination will start back up again,” he says.

Sona Bari, a spokeswoman for GPEI in Geneva, says, “any campaign in January will have our support." Whether that support will include staff in the field or will be limited to giving advice and guidance remotely to local officials will depend on the security conditions, she says.

Endgame delayed

Pakistan is one of just three countries where the polio virus has stubbornly resisted eradication efforts (Afghanistan and Nigeria are the other two). In 2011, Pakistan led the world with 175 confirmed cases. However, changes to the programme’s management had helped to spark a turnaround. This year Pakistan has recorded just 56 cases, and the virus has been cornered to some segments of the population in just a few regions. Global attention turned to Nigeria, the only country to see a year-on-year rise in polio cases this year.

Heidi Larson, an anthropologist who studies vaccination at the London School of Hygiene and Tropical Medicine, compared this week’s killings in Pakistan to a 2003 immunisation boycott in northern Nigeria, which was led by religious leaders. The virus rebounded in Nigeria and temporarily spread to other African and Asian countries that had already wiped out polio.

“In the same way that the northern-Nigeria boycott was a game changer, I think this is,” Larson says.

Nationwide polio vaccination, the foundation of the eradication campaign, should be reconsidered in some parts of Pakistan, Larson suggests. “I think we have to be thinking much more about embedding polio into some of the [routine] health services, so it’s not sticking its neck out.”

Zulfiqar Bhutta, an immunisation expert at Aga Khan University in Karachi, sees the killings as further backlash from the 2011 revelation that the US Central Intelligence Agency may have used a vaccination programme (though not of polio) in an effort to obtain DNA from children living in Osama bin Laden’s secret holdout in Abbottabad, in the north of the country. The affair turned polio into a “lightning rod” for extremists, says Bhutta.

Bhutta also worries that the latest violence will have a chilling effect on recruiting the tens of thousands of vaccination workers needed to carry out a national immunisation campaign. “Once you start killing young girls, who is going to volunteer for this kind of activity?" he asks.

The killings have been widely condemned by religious leaders and politicians in Pakistan, and sparked public protests led by vaccination workers who are calling for improved security. Durry hopes such sentiments will galvanise the country. “This is a major, major unmistakable tragedy, and it will create an opportunity to make this programme a true national cause, Durry says. "The bottom line is that the country is determined to finish the job."