Five months after the World Health Organization (WHO) announced that countries affected by cholera had to start rationing vaccine doses due to shortages, there is no immediate solution – yet cases are spiking.

In 2022, 36 million vaccine doses were produced and a similar number is expected this year.

“The South Korean manufacturer is making significant efforts with the help of [vaccine platform] Gavi, Bill and Melinda Gates Foundation and others to improve their production. Whether this will suffice to meet the need, that’s another story,” Philippe Barboza, team lead for cholera at the World Health Organization (WHO) told a briefing on Wednesday.

He added that there are plans to bring in a new manufacturer from South Africa for oral cholera vaccines but that will take time. 

“This is possibly a long-term solution. The question is what are we going to do in between?” 

The caseload for cholera during the first two months of 2023 is 40% higher than the caseload for the whole of 2022, according to WHO. The outbreak is severe in Burundi, the Democratic Republic of Congo (DRC), Malawi, Mozambique and Tanzania, said Barboza.

Barboza added that it is important to go back to the basics – improving access to clean water and sanitation – to achieve the goal of ending cholera by 2030. 

“Access to basic water and sanitation is a long-term solution. Many northern countries have controlled cholera only by improving water and sanitation. Unfortunately, this is something which still requires more political engagement and support,” Barboza said. 

African countries are particularly vulnerable

The case fatality rate (CFR) is 2.9% in Africa while the global average is 1.9%, according to Dr Otim Patrick Ramadan, the incident manager for cholera at the WHO African Regional Office. 

Along with the lack of clean water and sanitation, African countries suffering from cholera outbreaks are also grappling with several other climatic and non-climatic issues. 

“The cholera outbreak is happening in several contexts. We have had natural disasters, like Cyclone Freddy and we are currently trying to understand the extent and impact of the cyclone on Madagascar, Mozambique and Malawi. This has caused a lot of flooding.

“So we have seen outbreaks happen in the context of this cyclone, the flooding in Nigeria, Mozambique, and Malawi. And then the extreme end of those climatic events is also the drought in the greater Horn of Africa, Kenya, Ethiopia and Somalia,”  Ramadan explained.

Cholera transmission is closely linked to inadequate access to clean water and sanitation facilities. The Vibrio cholera bacteria spread in dirty water, and the spread can be accelerated during floods as well as when there is a shortage of clean water.

Regions with conflict are also vulnerable to cholera, such as parts of Cameroon, northeastern Nigeria, DRC, the North Kivu area of South Sudan, Somalia and Ethiopia, he added.

These challenges grouped with already existing public health challenges like Mpox, polio and measles cripple the countries’ capacities to respond. 

The vaccine challenge

 In October 2022, the WHO advised countries with cholera outbreaks to ration vaccine shots since the global stockpile of the vaccine was depleting rapidly. Countries were asked to administer single doses of the cholera vaccines instead of a two-dose regimen. 

The standard preventive approach to cholera is a two-dose regimen, in which the second dose is administered within six months of the first dose. This provides immunity against cholera for three years. 

WHO Director-General Dr Tedros Adhanom Ghebreyesus said that a single dose has proven to be effective in previous outbreaks, although the immunity it provides is limited. 

However, he emphasized that this is only a temporary solution and that a holistic and strategic approach must be adopted to prevent cholera outbreaks. 

“In the long term, we need a plan to scale up vaccine production as part of a holistic strategy to prevent and stop cholera outbreaks. The best way to prevent cholera outbreaks is to ensure people have access to safe water and sanitation”. 

Explaining that the situation around vaccines at present is not any different than what it was in October 2022, Barboza said that the demand for vaccines is increasing and unmet. 

Image Credits: World Health Organization (WHO), World Health Organization (WHO).