It’s a battle that’s taken longer than anyone expected.
On World Polio Day, the international campaign to end the paralyzing disease takes stock of what has been accomplished and recommits to eradicating polio worldwide. And this year, the campaign—by the World Health Organization, UNICEF, Centers for Disease Control and Prevention, the Bill and Melinda Gates Foundation, and Rotary International—is facing a reassessment.
In August, virologists proved that polio has been lingering in Nigeria, in a corner of the country with porous borders and shifting populations where travel had been blocked by terrorism. Now, even though the number of cases is small, Nigeria has been re-declared “endemic,” a place where polio has never stopped circulating—and planners worry the disease could spill from there into other parts of Africa.
The discovery is discouraging because success seemed so close. When the international campaign launched in 1988, there were 350,000 cases of polio paralysis every year, mostly in children. Last year, there were 74. So far this year, including four in Nigeria, there have been 27. As cases dwindled, it was assumed that the last places to harbor the virus would be Pakistan and Afghanistan, which for the past two years produced the only cases of natural polio in the world.
“We have never been as close to eradication as we are right now,” Dr. Reza Hossaini, UNICEF’s director of polio eradication, told me. (See “Polio Eradication: Is 2016 the Year?”)
He cited a number of reasons: the low case count, but also the occurrence of polio in only limited areas in each country, as well as diminishing genetic diversity in the viruses being retrieved from the wild. All of those factors increase the opportunity to draw a noose of vaccination around the areas where cases are still occurring.
But, Hossaini said, “we are still challenged to reach every single child, with an adequate number of rounds of immunization, in order to create enough immunity to entrap the wild virus.”
In the campaign’s favor: In the three countries where polio is entrenched, it is about to be the dry season. Polio virus, which hides in feces, moves through the environment more easily when the weather is damp. Not in its favor: For every known case, there may be up to 200 more cases of people carrying the virus without visible symptoms, and case counting has been affected by the same political difficulty that allowed the Nigerian virus to persist.
“This really is a reflection of the issue of security,” Dr. Thomas Frieden, the CDC’s director, told me. “The lack of security and lack of access meant that we did not have adequate surveillance, and polio spread for five years without being recognized. This is a warning for countries all over the world, but particularly in Africa.”
What happens next in polio eradication—in Africa and in the disease’s stubborn redoubts in Afghanistan and Pakistan—will be examined today in a press conference and World Polio Day observances at the CDC’s Atlanta headquarters.
The Role of Boko Haram
Planners might have predicted that Nigeria would be the African country where polio surged back. It has repeatedly been a polio hot spot, out of a combination of politics, religious disagreements, and random bad luck.
In 2003, Muslim imams in Kano state in Nigeria’s northern tier began preaching that parents should not allow vaccination, claiming the vaccine had been contaminated in order to harm Islamic children.
That may have been an authentic belief or part of political maneuvering between the Muslim north and Christian south of the country—but whatever the motivation, the result was a freeze on vaccination in northern Nigeria for more than a year. Any children who were not yet vaccinated, including the ones born in those months, were vulnerable. So much infection boiled up that the disease leaked over borders to reinfect 14 other African countries, which had already eliminated polio and turned their attention and vaccination funds to other problems.
In Nigeria, lingering distrust kept vaccination rates low for years afterward. So many children went unprotected that, in 2006, a random mutation of the weakened virus used in the oral polio vaccine, which took the virus back to its wild disease-causing state, sparked a national epidemic.
During the time that spike was being controlled, the terrorist militia Boko Haram—best known for kidnapping more than 200 schoolgirls in 2014—began gaining control of the same parts of the north where vaccination had been low. They cut off entire provinces, blocking the access needed by teams vaccinating children and epidemiologists counting cases. When the Nigerian military forced the militia out of parts of Borno state, in Nigeria’s northeast corner, the polio campaign discovered that wild polio virus had been circulating there for years. (See “How Northern Nigeria’s Violent History Explains Boko Haram”)
Porous Borders and Rising Risk
Now the entire area—Borno and three other Nigerian states and the adjoining countries of Chad, Cameroon, and Niger, which touch Nigeria at Lake Chad—are caught in what the World Health Organization calls a “complex emergency,” with more than 150,000 people fleeing across national borders and more than two million people internally displaced. Malnutrition and diseases of all kinds are rising, and the risk of polio is rising too.
“I’m quite worried about the Lake Chad area, because there are weaknesses of surveillance, and there are nomadic populations which could be introducing polio to a wider area,” Frieden said.
Lake Chad shifts in size with the seasons and is surrounded by wetlands, where the national borders are not monitored. Hossaini said: “It’s really hard to say what the population movement across the borders is, because the borders are so porous. There are checkpoints, but people cross for trade, and often they are crossing with children.”
In response to the discovery of polio in Borno in August, the eradication effort and the governments of Nigeria and five nearby countries mounted a vast emergency vaccination campaign: six rounds of vaccination covering more than five million children each time. But getting to them is challenging. According to maps prepared by the polio campaign, much of the northern half of Borno remains under the control of Boko Haram, and the militia conducts raids into Cameroon, Chad, and Niger as well.
In Borno, “certain (local government areas) are totally accessible, but they are very few,” Hossaini said. “Some are accessible, but high risk. And there are a few where the military has not been able to free them up. The military has created corridors where people can come from the rural areas into internally displaced persons camps, but outside those corridors only the military can go. We think the majority of the population is accessible in that manner, but we don’t know how many more families and children are still in areas where we don’t have access.”
Boko Haram is an explicitly anti-Western movement—its name has been translated as “Western education is a sin”—so to have any hope of succeeding, the polio campaign has to be led by locals.
“The Nigerian [polio] program is very robust,” Frieden said. “Anywhere they can get in, they do a really good job. They vaccinated 830,000 kids in the first two weeks” after the first two cases were found.
‘We Have to Save the Children’
Since its beginnings in the 1980s, volunteers from Rotary International have been the boots on the ground for the eradication campaign. They do not buy vaccines (other agencies in the campaign handle that), but their emergency donations cover training and rental cars and radio ads—even town criers in places where there is no power or mobile-phone coverage—and they volunteer as vaccinators themselves. (See “A ‘Polio Warrior’ Recounts Decades of Struggle Toward Eradication”)
John Germ, Rotary’s president, said their knowledge of local politics is crucial. “We have a strong committee in Nigeria,” he told me. “They are working with the governmental leaders, religious leaders, and they are trying to work with some of the conflict leaders, to allow us to get in where the children are. Getting in there with volunteers is very, very difficult to do.”
The challenge facing the campaign is to ring-fence the disease before the virus manages a repeat of its 2006 feat, leaking into surrounding countries where polio has not been present and vaccination has therefore slowed down.
That may be an even more difficult task than in Afghanistan or Pakistan. In those countries, most of the areas where polio survives are remote, with little traffic in or out. Nigeria, on the other hand, is the most populous country in Africa, and a crossroads for the rest of the continent.
There is no quick fix that can make the risk of onward spread go away; it requires yet more of the hard, grinding, repetitive work that eradication campaigners have been doing for almost 30 years.
“I think we will eventually eradicate polio back from Nigeria, and we will get it out of Pakistan and Afghanistan also,” Germ told me. “We have to save the children. We will get to that last child.”