Chad's vaccinators battle polio amid conflict and climate crisis in fight for global health security

The baby twisted and screamed in protest, her cries lost in the cacophony of the busy market in Dougia, Chad, as her mother gently pinched her cheeks to open her mouth. In one practiced motion, the vaccinator squeezed the drops into her open mouth. The mother turned back to her customer as the baby’s wails subsided, while the vaccinator took the baby’s hand and inked her tiny finger — proof she had received the vaccine, that she was now safe from polio.

And just like that, it was done. One more child made safe.

The vaccinator moved on, threading her way between potatoes and peppers, between pyramids of colourful spices and carts carrying sacks of flour, to the next child. She would do more than 100 that day, walking for seven hours beneath the burning sun.

This is what vaccinating a country means: tenacity, determination, and unwavering commitment. And Chad — a country of 20 million people stretched across desert and lake, conflict and hunger — is one of the last frontiers in the global war against polio.

If the virus survives here, it can resurface anywhere.

Each drop of vaccine is not just protection from polio for that one child — it’s a step toward global health security.

The most challenging frontier

The Lake Chad Basin represents one of the most challenging frontiers for polio eradication. Insecurity and conflict plague the region. Much of the population in the arid, remote area is unstable, with an estimated population of 6 million driven by trade, migration, climate displacement and insecurity, frequently moving across nearby common borders. 

With increasingly extreme climatic conditions threatening an estimated 55 million in the Lake Chad Basin/Sahel region with food insecurity, more and more are forced to join those on the move in search of resources to feed their families.

The frequent displacement and movement creates dangerous health risks. It enables the polio virus — and other diseases — to cross borders while simultaneously exacerbating the challenges for health workers of locating, targeting and vaccinating the local populations.

Indeed, the dangers of the virus spreading across borders are evident. In 2024, a total of 210 cases were reported across the four Lake Chad Basin countries, 140 of which resulted in paralysis. A total of 50% of the cases in Chad — which as of mid-March 2025 had an additional three cases with two resulting in paralysis — have been linked to a strain from Cameroon.

Don’t be fooled by the low numbers. Unlike diseases such as smallpox with unmistakable symptoms, polio can be more discreet — often flu-like, with only a relatively small percentage — one in 200 — resulting in paralysis. This makes detection — essential to controlling the virus — far more challenging. Compounding the problem, polio is highly contagious and spreads with ease: through a sneeze, a cough, a contaminated surface, or even tainted water. It is a formidable adversary.

It’s an adversary the Lake Chad Basin countries are taking on together. In April 2025, in an unprecedented regional collaboration, Cameroon, the Central African Republic, Chad, Niger, and Nigeria launched a coordinated campaign to eradicate variant type 2 poliovirus from the Lake Chad Basin. The synchronised effort set out to vaccinate 83 million children under the age of five across the countries between 24 and 28 April 2025.

Dangerous misconception

The common belief that polio has been wholly consigned to the past is a dangerous misconception. Although greatly reduced from prior decades, wild polio continues to have a tenacious grip in Pakistan and Afghanistan, where it is endemic and where cases are rising, while transmission and infection of polio variant two is sustained in the turbulent vortex of conflict and mobile populations in the heart of Africa, centred around the Lake Chad Basin countries — namely Nigeria, Cameroon, Central African Republic and Chad. 

These countries might seem far away but, as Covid-19 amply demonstrated, a virus in one area threatens health security everywhere. The warnings are flashing. Indeed, on 22 April 2025 the US Centres for Disease Control issued a global polio alert warning about polio detections in 38 countries, while in Europe, in the first months of 2025 alone, variant polio has been detected in the wastewater of 14 cities in five European countries. In response, both the US and European centres for disease control are now recommending a single polio booster for travel to the countries where there are outbreaks.

As long as these hotspots of polio exist, there remains a very real risk of a global resurgence. Eliminating the virus is critical to global health security.

The good news is that the tool to eliminate it — mass vaccination, which has successfully been used to reduce worldwide polio cases by nearly 99% since 1988 when the Global Polio Eradication Initiative was launched — exists. But the bad news is that the systems built to eradicate polio are being stretched to the breaking point — undermined by conflict, climate, and vanishing funds.

The crisis in Chad

Chad, a country of 20 million with a median age of just 15.7, is marked by widespread poverty and fragile infrastructure. As of 2025, the World Bank estimated that 40% of its population lived in extreme poverty. Its infrastructure is severely underdeveloped, with a limited and deteriorating road network across its vast 496,000 square miles. Only 10% of the population has access to electricity — one of the lowest rates globally — with access concentrated in urban areas home to just 25% of the population. In rural areas, where 75% of Chadians live, that figure drops to just 2%. 

Ranked the world’s most vulnerable country to climate change, Chad also faces deepening insecurity from armed insurgents in its once productive Lake Chad Basin. As violence spreads, livelihoods collapse, and resources dwindle, more and more people are on the move.

The scale of what’s required to vaccinate Chad’s estimated 3.2 million children under five is staggering. Every door, every house, every nomad’s tent and every shelter of the displaced, regardless of how remote or dangerous, must be visited to give every child under five the drops that will protect them from polio — and prevent transmission that could jeopardise global health security thousands of miles away.

This is the low-tech reality: thousands of vaccinators walking mile after mile in 44°C heat on dirt tracks, grappling with severe — and shrinking — resources. Too few vehicles to reach scattered villages and makeshift encampments in a country where displacement is increasingly common. Roads are scarce or nonexistent. Unreliable electricity that fails to freeze the cool packs necessary to keep vaccines potent.

But the work doesn’t start here. Vaccination marries the low tech with the high tech. Surveys, censuses, data from schools and health centres — all is verified by teams on the ground while community leaders and nomad chiefs pinpoint where mobile communities have settled.

All this information goes to World Health Organization offices in N’Djamena, where the data is crunched and added to comprehensive maps that detail every village, every camp, every nomad route, and ultimately vaccination status. As vaccinators work, they mark off each child reached on paper.

However comprehensive the maps, however detailed the data on charts, mobile populations on the move — crossing borders, fleeing insecurity, floods, drought — defy the tracking essential for disease surveillance and identifying — and hence interrupting — chains of transmission.

To this end, for the first time, a new high-tech tracking system has been rolled out and is being trialled throughout the country. Called GTS (Global Tracking System), it operates on software installed on a SIM-less mobile phone, which the vaccinator keeps in their pocket as it wirelessly beams back the tracking data of the area visited. Imperfect and not yet capable of completely executing the task at hand, it is expected to be improved moving ahead.

The crises converge

The province of Hadjar Lamis stretches from the volatile shores of Lake Chad to the porous border with Cameroon. It is here that the crises of insecurity, violence, climate change and porous borders converge. It is here too that the trajectory of Chad’s mounting challenges over the past decade are plain to see. In 2015, 20% of the population, according to the UN, was in need of humanitarian assistance. Today, that figure has doubled to nearly 40%, according to the Global Humanitarian Overview, driven by “climatic hazards, health emergencies and conflicts”.

Nowhere personifies it quite as clearly as the Hotel Dougia.

The Hotel Dougia occupies a charmed location on the Chari River a mere two hours north of N’Djamena, Chad’s busy capital city. A haven of tranquility, it was long a favorite weekend spot for N’Djamena’s city dwellers, who would fill the resort’s circular air-conditioned huts, enjoying drinks and mouth-watering meals poolside, while watching the sun set over Cameroon on the opposite side of the river’s glistening waters, rippled by the occasional passing pirogue.

Today, however, its swimming pool is half filled with green-yellow stagnant water, the broken frame of a rusty play structure stands idle, and hordes of monkeys pluck mangos from the trees overhead, greedily taking a single bite before chucking them down to the ground and helping themselves to another. Yet, despite being pretty much derelict, the resort remains defiantly open.

Despite being the only place to stay for many miles, few pass through in need of its hospitality.

“ Only two in January, and two in February,” the manager recalled in April, stroking his chin and squinting as he struggled to remember. “None in March…”

All changed in 2015 when neighbouring Nigeria’s Boko Haram insurgency surged across the border into Chad. Jihadist flags aloft, they occupied the lake’s islands, kidnapping, killing and displacing thousands. Insecurity only grew from there. By the beginning of 2017, violence had displaced more than 100,000 in Chad and pushed 7,000 refugees from Nigeria and Cameroon into Chad in search of safety. The insecurity rapidly decimated the area, turning the once-popular province laced with second homes into the run down, impoverished area accessed by a slow, dusty potholed dirt road that it is today.

Nothing has improved since then — on the contrary, the insurgency has only intensified and expanded, with new actors like the Islamic State West Africa joining the conflict. At the same time, climate change continues to drive large-scale population movements, deepening the cycle of extreme poverty. 

According to the World Bank, 40% of the population now lives in extreme poverty, a surge attributed in part to the devastating floods of 2024. These floods, as reported by the UN, killed 576, displaced 1.9 million, destroyed more than 432,000 hectares of crops, and led to the loss of more than 66,000 head of livestock,  leaving more than 2.4 million people severely food insecure — with conflicts over dwindling resources multiplying.

This convergence of conflict, climate, and mass displacement isn’t just deepening an already complex, vast humanitarian crisis — it’s also a threat to public health. As people are pushed into increasingly remote and unstable areas, conditions become ideal for viruses to spread undetected.

The displaced

To see what this means today, continue past the famed rocks after which Hadjar Lamis province was named and which used to draw hordes of tourists; continue on the unmarked track — careful not to go too slowly, for if you do and your wheels get stuck in the deep sand, there’s no one to help. In the distance, bodies of water shimmer like mirages under the sun — floodwaters from the devastating rains of 2024 — which claimed five lives in the village closest to here — still not fully receded. 

Eventually, in the middle of this sandy nowhere, appears a glimmer of life and an encampment of makeshift shelters made of twigs and sticks. There are many of these settlements scattered, hiding in the remote desert realms of the region, many of which are dangerous, presenting a daunting challenge for vaccinators who can’t risk lingering.

There are more than 10,000 people here, most of whom arrived less than six months ago, fleeing Boko Haram, the floods — or both. Among them are many children under five, vulnerable and unvaccinated.

Mothers and children cluster around as 29-year-old vaccinator Adam Bari squeezes drops into mouth after mouth, before setting out to reach children in each of the shelters. With shelters widely spaced and extending into the desert as far as the eye can see, the vaccinators work as fast as they can in order to reach as many children as possible. 

The numbers have rocketed this year — but vaccinators only have limited time here.

Adam squeezes drops into the open mouth of Hawa bi Shara’s youngest, inks her finger and walks on to find the next child, a trail of children following behind, pied piper-like.

Colourful patterned fabrics hang chaotically from the walls and ceiling of 40-year-old Hawa’s shelter. There is no furniture — just a platform for sleeping that is piled with blankets. Left alone after the children depart with Adam, she falls silent, an air of sorrow engulfing her. The mother of seven arrived here four months earlier, after her village was attacked by Boko Haram.

“They came at night,” she says softly, haltingly. “We were sleeping when they came — they captured four men from the village and slaughtered two immediately — in front of us. One survived because they thought he had died. They took the fourth man with them — and two nights later they killed him too,” she pauses. 

It happened in front of us. We were crying please come to us and crying for help, but no one came.

“It happened in front of us. We were crying please come to us and crying for help, but no one came. The men who were killed were our neighbors — Adam Omar and Amar Danah. One of their fathers lost his mind from the trauma. But then we couldn’t escape right away — our village was surrounded. We couldn’t sleep, we couldn’t eat. Every night we asked ourselves if it would be our last. A week passed before we could flee. Some people had money for trucks. We didn’t. We came here on horses.

“Now we’re safe from Boko Haram — but not really safe. There’s nothing here. Before, we fished and farmed. Now, we wait. If you have food, you eat. If you don’t, you don’t. We’re just praying to God. We can’t go back. We’re afraid they’ll kill us.”

Kaltuma Bashir, 80, is the Chief of Women here. A graceful woman with an air of compassionate authority, she sits straight and proud. First displaced by floods that claimed her home, her crops, and the livelihood she had spent decades building, she was uprooted a second time when Boko Haram attacked the camp where she had sought refuge. She too arrived here just four months ago.

“Women’s life is difficult here,” she says. “They have three or four children on their hands, and they have lost everything to the floods and Boko Haram. Children too are suffering. I don’t see a future for them here. There is no school, no activities, no land to farm.”

She pauses, as she watches a vaccinator approach a group of children nearby. A midwife who has delivered countless babies, she smiles approvingly. In a place with no schools, no future, no hope, at least the children will be protected.

But time is up and the vaccinators haven’t been able to get to every child.

“This year there are so many internally displaced people because of the insecurity,” Adam says. “This year the number is huge — there are many more than we had last year.”

Yet fewer resources are available. It is a refrain heard throughout the country.

Overwhelmed resources

Dr Manassey heads up the health centre in nearby Karal. He is responsible for a vast area of 200 square kilometers, an area incorporating numerous camps like this, which shelter thousands displaced by Boko Haram violence, others displaced by climate and flooding, as well as dozens of nomad encampments.

“This year, we have many more people, many more internally displaced people this year compared to last,” he says. “Many more who need vaccination. Last year, we had 32,900. This year, we have more than 35,000.”

Resources haven’t kept up. With only four vehicles it is impossible to reach every settlement, every nomad encampment. They rely on community involvement. 

“Because of the lack of resources, the community is helping in areas where we don’t have enough — they will give a moto or a pirogue.”

In nearby Mani, Eric Ldjutoloum, 48, has been in the district for six years, for the past year and a half as Head of the Health Point. The population has grown, he says, but his resources have shrunk dramatically.

“We had nine teams before,” he explains, “But this year they have given me only three. We don't know why — it’s the boss who sends us the info — and I can’t ask. They just give us instructions and we obey. It might be the US cuts in aid.”

It is not enough, Ldjutoloum admits. He worries about the consequences. 

“We can’t get to all the zones because of the team reduction. We just can’t control all the areas with so few teams so there will be a risk of propagation. We also can’t control where people cross the river to and from Cameroon where there are no formal crossings. This too can lead to the propagation of the virus. It’s all a threat to health security.”

They work hard to reach as many children as they possibly can, starting each day at 5am, rallying volunteers from the community to help. 

“The worry is propagation,” Ldjutoloum says. “We want to work, we have the spirit of the sacrifice and we deploy ourselves as hard as we can so we can reduce the worry.”

Border vulnerabilities

Across the country, mobile communities — displaced by conflict, by climate, or both — are the primary focus of the vaccination campaign. They’re the hardest to track, the easiest to miss. 

In Karal and Mani, the challenge lies in reaching those scattered in remote encampments and makeshift camps. In Dougia, the difficulty is different — but the stakes are just as high.

A bustling border town perched on the Chari River, Dougia draws hundreds to its weekly market. It’s here that Chad meets Cameroon, not just in trade but in transit — and transmission. Unlike the informal crossings used by nomads and displaced families, this is a formal checkpoint, a strategic opportunity to intercept the virus.

But opportunity means little without resources.

“In 2021, we had nine teams,” says Halima Saadia Macoungi, 38, who has been heading up the health centre in Dougia since 2020. “But this year, we only have five.”

It makes no sense. The number of teams is meant to correspond with the population numbers.

“But now the population has increased,” she says, mystified.

The centre is responsible for 13 villages spread over 13 square miles, the crowded border, and the overflowing market. It has no vehicles. Teams of two travel by motorbike when possible, then walk — door to door, hour after hour, under a punishing sun — trying to reach 600 children a day over the course of the four-day campaign.

Today, short staffed and under equipped, there is only one team at the border; two to cover the market and two responsible for the 13 villages.

“We do what we can,” Macoungi says. “But it’s not enough.”

The gravest threat

But the campaign to eradicate polio now faces its gravest threat: the abrupt withdrawal of US funding from 80% of global health awards worth $12.7-billion, funding that includes support for polio vaccination efforts. The US has historically contributed 21% of the Global Polio Eradication Initiative’s budget; its exit has left a gaping shortfall and endangered the success of the initiative.

The fallout is already being felt. The US has terminated funding for 5,800 global health programmes, including a $131-million grant to Unicef’s polio immunisation programme that funded planning, logistics and vaccine delivery for millions of children. The WHO’s Global Polio Laboratory Network — the nerve centre for detecting outbreaks — faces an uncertain future as more than 130 CDC staff working on polio eradication live “month to month” not knowing if their funding will continue.

There can be no complacency about the potential consequences. In a whistleblower memo dated 25 March 2025, Nicholas Enrich, then Acting Assistant Administrator for Global Health at USAid, warned that the pullout could result in “an additional 200,000 annual cases of paralytic polio, and hundreds of millions of new infections”.

Global health security hangs in the balance.

In our interconnected world, a disease can spread from any remote village to any major city in as little as 36 hours. 

“Scenarios for polio being introduced into the US are easy to imagine,” warns CDC’s Dr Greg Wallace. “One person infected with polio is all it takes to start the spread if others are not protected by vaccination.” 

The virus doesn’t respect borders — in the past decade alone, at least 40 polio-free countries have been reinfected through international travel.

The relentless pursuit

The sun dips lower, casting long shadows across the market. Trucks are loading up, vendors pack away their wares. Donkey carts are turning back toward distant villages. The pace slows, but the air is still buzzing with activity.

Vaccinator Julie Ada, 45, pinches the cheeks of one last child before finishing her long day. She inks the tiny finger and looks around, sighing. Behind her are the hundreds of children who will not contract polio, hundreds of families spared that particular torment.

Despite drastically reduced resources and increased need, the vaccination teams persist. 

“We can’t reach everyone,” Macoungi admits quietly. “But we keep trying.”

The battle against polio in Chad is about more than just eliminating a disease. It is about the survival of global health security itself.

As funding cuts threaten vaccination campaigns worldwide, as children go unvaccinated, as surveillance fails, the very infrastructure protecting global health is imperilled. The WHO warns that continued funding shortfalls “may potentially delay eradication” and “lead to more children getting paralysed” — not just in Chad, but everywhere the virus can reach.

And when global health security fails, it fails for all of us. DM

Susan Schulman (@susanschulman23) is an award-winning video, photo and print journalist. The reporting for this story was made possible through support from the UN Foundation.