Zambia, Zimbabwe and Malawi are at the epicenter of the deadliest cholera outbreak in southern Africa in at least a decade. The global stockpile of vaccines to limit the disease's spread has run dry.
More than 1,000 people have succumbed to cholera, while tens of thousands across Africa have been infected in a series of deadly cholera outbreaks since the beginning of 2024.
The hardest hit nations are the Democratic Republic of the Congo, Mozambique, Zimbabwe , Zambia in southern Africa, and Ethiopia further north.
Zambia is being battered by its worst outbreak ever, with more than 740 cholera deaths recorded since the onset of seasonal rains in October 2023.
The highly contagious bacterial disease can cause severe diarrhea and dehydration within hours of infection. When people are quickly treated, less than 1% die. But the death rate in Zambia, one of the world's poorest countries, is more than 3%.
How does cholera spread?
Cholera outbreaks often occur in disaster-hit areas or poorer communities lacking safe drinking water and proper sanitation. Those who depend on untreated water from rivers and ponds or live in slums and refugee camps are at particular risk.
This is because the Vibrio cholerae bacteria that causes cholera is shed in the feces of the infected host, with the bacteria spreading rapidly if it gets into food or water supplies.
"Just imagine one household where the toilet is pretty close to the place where people fetch their water, so there is a transmission of contamination between the toilets and the water that people drink," explained epidemiologist Yap Boum, the head of the Pasteur Institute of Bangui, a non-profit research foundation in the Central African Republic.
"And then in settings like refugee camps, where you have a concentration of people, the water that is being used is highly contaminated."
What is fueling Africa's current cholera outbreaks?
There are a host of reasons for the rash of simultaneous cholera outbreaks across so many southern African countries, said epidemiologist Boum.
"Cholera is a marker of inequality, mostly affecting countries that are exposed to conflict, insecurity and poverty," he said. Those factors are all present in each of the African nations currently battling cholera outbreaks.
Another factor is climate change.
"Increasingly frequent and more severe flooding linked to climate change has an impact [on cholera outbreaks] too," wrote water management expert Anja du Plessis, an associate professor at the University of South Africa, in response to DW questions. "Cholera occurs more in the rainy season, which the region is currently experiencing."
"Flooding results in more run-off containing more pathogens, increasing the risk of contamination."
What about the cholera vaccine?
To make matters worse, stockpiles of the only available cholera vaccine are empty as demand soars.
Only one manufacturer, based in South Korea, currently makes an oral cholera vaccine. It is churning out 700,000 doses a week, but demand is four times greater than it can supply, according to Doctors Without Borders (MSF).
This despite an October 2022 International Coordinating Group (ICG) on Vaccine Provision recommendation to replace the long-standing two-dose regimen with a single dose of the cholera vaccine in an effort to preserve stocks.
Unlike routine childhood vaccinations, cholera vaccines are produced on a "needs basis," said Edina Amponsah-Dacosta, a vaccine expert with the Vaccines for Africa Initiative based at the University of Cape Town in South Africa.
"We tend to use cholera vaccines for mass vaccination programs whenever we have outbreaks -- to control the outbreak of the disease. That means we tend to produce a limited amount for a limited number of countries."
Are vaccines the solution to cholera containment?
The past decade has seen a massive increase in cholera vaccines produced, jumping from roughly 2 million doses in 2013 -- when the cholera stockpile was set up -- to 36 million in 2022.
But that still isn't enough to keep up with the current unprecedented surge in global cholera cases.
"If cholera were similarly affecting Western countries, I believe we would have the highest amount of vaccine available, but that is not the case," said Boum, who previously headed MSF's research arm, Epicentre.
At the same time, every expert interviewed for this article warned that vaccines would never be the silver bullet that will stem the spread of cholera in southern Africa.
Rather, a vaccine is just one of many tools to help fight disease. Others include improving community health messaging about boiling water and good hygiene practices, like washing one's hands, providing safe and reliable water sources, and increasing water quality testing and monitoring.
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Why isn't Africa producing its own cholera vaccine?
In 2022, the South African-based company Biovac signed a licensing contract to manufacture oral cholera vaccines in a deal heralded by international health experts. But Biovac's vaccines can't be used to curb current outbreaks because production isn't slated to start until 2026.
Having a regional manufacturer is an important step in the right direction though, say both Yap Boum and Edina Amponsah-Dacosta.
"Diseases are not prioritized the same way in all parts of the world," vaccinologist Amponsah-Dacosta told DW. "With cholera, we have just one manufacturer with limited global interest in a disease such as this one. It creates the situation that we're seeing now in terms of the dwindling stockpile."
"If you increase manufacturing capacity in parts of the world that experience the disease the worst, it just means that they are able to take ownership and rely on their own resources and better support their health programs. "That is critical."
Edited by: Chrispin Mwakideu
