How cholera vaccines are used to respond to outbreaks
Over the last two years, countries’ ministries of health and organisations like Doctors Without Borders (MSF) have been trying to respond to a string of cholera outbreaks around the world. Why are we seeing so many outbreaks? What’s causing them? And do we have the tools and resources needed to respond to them? MSF’s International Medical Coordinator, Dr Daniela Garone, explains in this interview.
What’s the current situation with cholera, and how did things get so bad?
Currently, 16 countries around the world have declared an active cholera outbreak, with many countries reporting larger and prolonged outbreaks. MSF teams are responding to cholera in some of these countries, including Zambia, Zimbabwe, Ethiopia, the Democratic Republic of Congo and Mozambique. Early data shows the number of cholera cases in 2023 rose by 40 per cent over 2022, and deaths increased by over 80 per cent. Over 735,000 cases were reported last year across 30 countries. Just in January this year, nearly 41,000 cases and 775 deaths have been reported.
MSF has responded to many cholera outbreaks over the last 50 years. Cholera is an extremely virulent disease transmitted through the ingestion of contaminated food or water. While the triggers for cholera outbreaks like poverty and conflict are enduring, today we face a growing threat from climate change, with increased droughts – which can force people to use unsafe sources of water – and floods, which can spread the cholera bacteria. We also see a lack of maintenance of water, sewage and waste management infrastructure due to deteriorating economies, lingering political crises, wars or conflict, or increased movements of people, such as those who are displaced or refugees. A combination of these factors has driven cholera in the countries where we’re responding to outbreaks.
%20(1).jpg "Cholera in Zimbabwe | @MSF | 18/01/2024")
How can we respond to cholera?
First, it’s important to highlight that cholera is a preventable disease. Good access to clean water, proper sanitation infrastructure, and hygiene measures reduce the likelihood of cholera outbreaks. Oral cholera vaccines can also be used to prevent and respond to outbreaks.
Unfortunately, for the last two years, the demand for oral cholera vaccines has exceeded up to four times the global production capacity. Limited manufacturing capacity has meant that only so many doses are being made. And with the extraordinary number of outbreaks around the world, the increased demand for the vaccine has far outstripped supply.
Measures have been put in place to try to maximize the limited availability of cholera vaccines. In October 2022, the International Coordinating Group (ICG) on Vaccine Provision1 – of which MSF is a member – made a last-resort decision to temporarily reduce the number of cholera vaccine doses given to people from the recommended two doses to one, to stretch out supplies. With two doses, immunity against infection lasts for three years. A single dose will provide some protection, and that’s why we are using this approach, but it is unclear how long immunity will last.
What’s the situation with the oral cholera vaccines today?
Unfortunately, nearly 18 months since the ICG suspended the two-dose strategy for outbreak control, the situation has worsened. Today, only one manufacturer makes the pre-qualified version of the vaccine2 and is producing at their maximum current capacity after another manufacturer left the market at the end of 2022.
Even the one-dose strategy has not been enough. In 2023, 76 million doses were requested by 14 countries to implement a one-dose strategy, but only 38 million doses were available. If a two-dose strategy had been implemented, the gap in the number of cholera vaccines would be as high as 104 million doses. And this is for outbreak response; it’s not even counting the doses needed for preventive campaigns.
Doses are being manufactured each month – but all the doses in production until mid-March have already been allocated, so the stockpile is currently empty. And unfortunately, there is no short-term solution to increase vaccine production.
.jpg "Cholera training in Nampula, Mozambique. Between January 23-25, our team in Nampula province led a training session on cholera outbreak response management and coordination. This initiative brought together diverse organizations and local health authorities, including the World Health Organization, UNICEF, and Mozambique's Ministry of Health, marking a significant step forward in our preparedness to combat cholera. The training was a melting pot of expertise, engaging stakeholders from grassroots first responders to decision-makers to streamline a robust readiness to face cholera outbreaks head-on. Photographer: Lourino Pelembe | 23/01/2024")
With a limited number of cholera vaccines, what else can countries and MSF teams do?
Cholera is preventable and treatable. While vaccines are a critical tool, they are not the only tool we have. There needs to be good access to clean water and sanitation infrastructure such as toilets and waste disposal. They need to be adequate to the size of the community and protected from contamination. Engaging people in communities on hygiene measures, using soap, waste management, how to avoid contamination of water sources, and putting communities in charge of maintaining water points – all of this contributes to more effective outbreak control.
Access to timely testing and laboratory confirmation of cholera is not broadly available in many settings, and this delay in declaring an outbreak can affect an appropriate and timely response. Diagnosis has been happening late in many areas, and cholera is very contagious, so by the time there’s a diagnosis, the bacteria have already been spreading. There needs to be more efforts in wider and earlier diagnosis of the first signs of cholera symptoms.
Although cholera can kill within hours if left untreated, treatment is simple, and nobody should die of cholera in 2024. Treatment requires rehydration, including simple oral rehydration and a course of antibiotics for people with more severe cases. But the hard reality is that many people don’t have timely access to those. Quickly implementing sufficient oral rehydration points in multiple parts of an affected community – ensuring wide access to them – and scaling them up as needed is crucial.
%20(1).jpeg "MSF participates in the fight against a cholera epidemic in the context of a regional outbreak In the Massala health zone, which accounts for more than 50% of cholera cases in the Ndola district, we are working simultaneously on several fronts: support for the establishment of a patient isolation and treatment unit, specific triage at the health centre level and collaboration with epidemiological surveillance services and community stakeholders. This allows our teams to detect “clusters” of cases. Based on this case geolocation work, activities related to water, hygiene and sanitation are carried out via the chlorination and rehabilitation of water points, as well as the distribution of water kits and hygiene at the household level in the most affected areas. Photographer: Carla Melki | 19/02/2024 | Zambia.")
MSF has been responding to cholera outbreaks for the best part of 50 years – we know this saves lives very quickly. Setting up a cholera treatment centre – whether it’s in an existing structure or tents – is possible within 24 hours.
So, in summary, in addition to vaccination, our focus to prevent and respond to cholera outbreaks must first be on access to clean water and sanitation, improved disease surveillance, better communication and engagement with communities, and improved access to healthcare for those who are sick.
Hannah Maitre
About Doctors Without Borders (MSF)
Doctors Without Borders (MSF) is a global network of principled medical and other professionals who specialise in medical humanitarian work, driven by our common humanity and guided by medical ethics. We strive to bring emergency medical care to people caught in conflicts, crises, and disasters in more than 70 countries worldwide.
In South Africa, we run a non-communicable diseases (NCDs) project in Butterworth, Eastern Cape province, to improve care for patients with diabetes and hypertension. The project focuses on improving screening, diagnosis, management and prevention through advocacy, research, health promotion, training and mentorship of Community Healthcare Workers (CHWs).
At the end of 2023, we handed over our Tshwane Migrant Project to authorities and a local Community-Based Organisation after building the capacity to work with undocumented populations. The project provided access to medical care for undocumented people and migrants and actively advocated for continued access.
After 12 years of operations, we closed our HIV/TB project in Eshowe, KwaZulu-Natal province. The project’s community-oriented approach helped to increase the integrated management of HIV, TB, diabetes and hypertension through nine community-based ‘Luyanda’ sites, which were successfully handed over to the DoH. Many achievements were made in the task-shifting of TB health promotion activities to teachers in schools, and we shared valuable feedback with the DoH on the decentralisation of Drug-Resistant Tuberculosis (DRTB) services to the primary healthcare level.
After 22 years of activities and campaigning, we closed our HIV and TB project in Khayelitsha, Western Cape, in 2020.