"Lifting all boats" with a heat-tolerant and cost-effective vaccine against goat plague

Photo credit: Small stock are multipurpose, endlessly renewable assets for people and national economies across vast regions of Africa, where PPR has a disproportionate impact on poorer households, which typically cannot afford cattle. ILRI/Stevie Mann. 

Tackling devastating livestock losses in West Africa

Peste des petits ruminants (PPR), commonly known as goat plague, is among the most contagious and fatal of livestock diseases affecting goats and sheep, especially among poor households of developing countries, where it crushes rural livelihoods and sends millions into destitution every year. Goat plague has been spreading into new countries over the past two decades. It causes more than USD 2 billion in global losses annually, with one-third occurring in Africa. The disease has a particular stranglehold on Mali, where one-third of West Africa’s small ruminants are raised.

A vast country larger than California and Texas combined, Mali is arguably ground zero in the current battle to eradicate PPR from the face of the Earth. Despite its 2022–2028 national strategy to eradicate PPR, Mali 2023 vaccinated just 9% of its small ruminants, compared to 64% of the country’s cattle against contagious bovine pleuropneumonia. This is partly due to cattle having a higher individual value than small stock and fewer of them. It also appears that Mali’s elites value small stock, often raised by women, less highly than they value cattle, which are raised by men, who also tend to be wealthier and more able to afford animal vaccinations.

One reason for this is that Mali’s elites value small stock, often raised by women, less highly than they value cattle, which are raised by men, who also tend to be wealthier and more able to afford animal vaccinations. Another reason is that the PPR vaccine currently available, called “Ovipeste,” is thermolabile, meaning it requires constant cold storage—called a cold chain—that is difficult to maintain in Mali’s brutally hot climate and remote pastoral frontiers.

But while the region’s policy support for the livestock sector may be stronger on paper than on the ground due to constrained capacity to implement livestock development support, demand for the thermotolerant PPR sheep and goat vaccine in Mali and its neighbors is robust and growing yearly. Many other countries within and outside of Africa are facing the scourge of PPR, including most recently Greece. Challenges in maintaining cold chains, especially for the last mile of delivery in semi-arid frontier lands where goat and sheep herding is widespread, are common.

A new hope has emerged in the form of “OvipestePlus,” a heat-tolerant vaccine developed jointly by CGIAR’s International Livestock Research Institute (ILRI), Mali’s Central Veterinary Laboratory (LCV), and India’s Hester Biosciences Limited. This new “thermotolerant” vaccine retains potency up to 9 days at 32.5°C to 38.5°C and 7 days at 40°C; and for 5 hours after reconstitution with water, making it far better suited to Mali’s challenging conditions than the thermolabile PPR vaccine, which is deactivated by heatand only lasts for 1 hour after its reconstitution. Validation by the African Union’s Pan African Veterinary Vaccine Centre (PANVAC) and trials showing 99% efficacy confirm the technical superiority of the new thermotolerant vaccine.

With Mali’s (hot and rising) temperatures and generally poor infrastructure, the validated thermotolerant PPR vaccine OvipestePlus shows technical superiority over the current thermolabile PPR vaccine Ovipeste.

Why a vaccine? Vaccines remain the gold standard—the most durable and cost-effective instrument—for ensuring animal health. Just one vaccine injection provides small ruminants with lifetime immunity to PPR. Who benefits: Scaling up deployment of the thermotolerant vaccine in Mali will serve as a “force multiplier”, amplifying a wealth of tangible benefits stemming from healthy and productive stock, particularly for poor women.

Why now? Scaling the vaccine now is particularly timely. Earlier this year, the Pan African Programme for the Eradication of PPR and Control of other Small Ruminant Diseaseswas launched. At the same time, the European Union has increased its support to the African Union Inter-African Bureau for Animal Resources (AU-IBAR) and PANVAC to eradicate the disease from Africa by 2030. The World Bank has already made a further large commitment to support PPR vaccination in Sahelian countries.

This cooperative enterprise is thus a once-in-a-generation chance to eradicate PPR from the continent. Mali’s successful deployment of the thermostable OvipestePlus vaccine is central to this effort.

Scaling Ambition, Timeline, and Strategy Design

The twin goals of the PPR vaccine scaling strategy are to eradicate PPR in Mali by 2030 using the heat-stable OvipestePlus vaccine and to help make Mali a sub-regional hub for the vaccine’s production and distribution.

Scaling ambition/timeline

• Phase 1 (2025–2026): Control stage
  LCV increases its annual vaccine production capacity from 12 to 15 million doses, obtains financing to install increased thermotolerant vaccine manufacturing capacity, and increases the percentage of vaccines that are thermotolerant from 40 to 50%
• Phase 2 (2028–2030): Eradication stage
  LCV increases its annual vaccine production capacity from 15 to 26 million doses and the thermotolerant percentage from 50 to 91%. Vaccination coverage in the country reaches 76% and 80% in 2029 and 2030, respectively, which is the rate needed to achieve eradication.
• Phase 3 (2031): Maintenance stage
  LCV produces 17 million thermotolerant doses annually (14M for Mali; at least 3M for its neighbors)
• Phase 4 (2032): Validation stage
  LCV conducts extensive testing to demonstrate that eradication has been achieved and produces just 7 million doses of the thermotolerant vaccine for Mali.

Strategy design

Regional variations within Mali in cost-effectiveness guide where to prioritize the rollout of OvipestePlus, with the country/s districts divided into three kinds of clusters depending on their temperatures, instability, remoteness, and numbers of goats and sheep: Cluster 1 (38 districts), with optimal conditions for vaccination, targets 11.5 million animals at USD 1.14 per dose; Cluster 2 (20 districts), with logistical challenges in the north, targets 22.8 million animals at USD 20.48 per dose; and Cluster 3 (11 districts), with large herds and variable security, targets 1.6 million animals at USD 0.14 per dose. Regardless of the cluster, the average total cost of OvipestePlus to Mali’s livestock owners is USD 2.00 per animal.

Strategy benefits

1. Less cost: Though slightly costlier to produce than Ovipeste, the thermostable OvipestePlus vaccine is cheaper to deploy due to reduced wastage and cold chain needs. Hence, vaccine coverage will be higher and quicker with OvipestePlus.
2. Less waste: Vaccine losses are highest at the last injection stage, where OvipestePlus reduces spoilage because it can last longer than Ovipeste after being reconstituted.

An analysis conducted in 2016 of the proposed global PPR eradication program determined a cost-benefit ratio of 33.8 and an internal rate of return of 199%.

A 2022 study in Mali found that PPR outbreaks caused household income losses ranging from 6% to 15%. A 2023 study in Senegal found that at the prevailing vaccination coverage rate of 26.5%, farm households practicing PPR vaccination annually earned an average gross margin of USD 69.43 more than those not vaccinating, and that the average consumption of mutton and goat meat increased by 1.13 kg per person per year.

Partnerships, Governance, and Financing

Institutional roles

• Mali’s parastatal Central Veterinary Laboratory (LCV) will produce the vaccine and scale up its production.
• Mali’s National Direction for Veterinary Services (NDVS) will coordinate public and private veterinary service distribution and manage public–sector veterinarians.
• ILRI will provide technical support, monitoring, evaluation, and policy engagement.
• Public and Private vets & NGOs will deliver the vaccine to remote areas.

Proposed governance and operational framework

• A steering committee led by Mali’s Minister of Livestock or a representative will coordinate the actors’ work, review, and adopt technical and financial reports.
• A technical committee led by Mali’s director of veterinary services will coordinate vaccine production and distribution and veterinary agent training. It will also conduct sero-monitoring surveys, share findings, and maintain partnerships with relevant regional bodies.
• A knowledge management (KM) team, including KM, monitoring and evaluation, communication, and policy experts, will track gender data, communication reach, and training needs.
• Public- and private-sector veterinarians and NGO implementing agents will adopt and contribute to an agreed-upon monitoring system.
• Local community innovation platforms will undertake complementary efforts, such as providing small ruminant feeding, fattening, and marketing, which can increase vaccine uptake.

Financing

The total funding required for the five-year scale-up is estimated at USD 108 million (2025–2030), with 56% of that going to vaccine production. This price includes bundling the delivery of OvipestePlus with the Pasteurellosis vaccine, which reduces costs.

Responsible Scaling and Global Implications

In Mali, as elsewhere in West Africa, the daily household chores of raising small ruminants—from taking the animals out to graze, to gathering, preparing, and distributing feed, to watering and milking, to caring for sick animals—are carried out largely by women and children. However, at present, it is unknown whether women are accessing Mali’s vaccination services, because the monitoring systems employed do not collect information on the gender of the owner of vaccinated animals. Moving forward, the monitoring system needs to capture the gender and major age group (youth vs adult) of the owners of the animals being vaccinated. This information can be used to better inform the vaccine communication and implementation strategies and advocate for improved infrastructure and training, enhancing the efficiency and ease of the vaccination process. In addition, communication campaigns in rural areas will target both men and women and use trusted community influencers.

Livestock farmer organizations and cooperatives, as well as the voices of Mali’s many women livestock keepers, will need to be supported and strengthened to push for small ruminant vaccination campaigns and convince policymakers to give the small ruminant sector a higher national priority. And while currently Mali’s livestock owners pay for all their animal vaccinations, it is clear that fully subsidizing PPR vaccination would greatly speed the eradication effort, especially among the poor.  

Environmental considerations

While thermotolerant vaccines can benefit the environment by reducing medical waste and spoilage, enabling people to keep healthier animals can increase herd sizes, thus making better pasture management essential.

ILRI‘s PPR Task Force supports an enabling environment

Earlier this year (March 2025), ILRI, one of the three institutional developers of the thermotolerant PPR vaccine, established a thermotolerant PPR Vaccine Task Force to galvanize support for OvipestePlus by cultivating and convening allies and navigating the relevant political, development, and immunization landscapes, specifically by:

1. Ensuring that AU-PANVAC and WOAH integrate the thermotolerant vaccine in their global vaccine bank options.
2. Providing technical support for the Global PPR eradication effort coordinated by FAO and WOAH.
3. Mobilizing AU-IBAR, Hester Biosciences Limited, and national African vaccine manufacturers to produce the thermotolerant vaccine.
4. Determining the potential demand for the thermotolerance PPR vaccine within national PPR control programs and identifying priority countries for the vaccine’s rollout.

Potential outcomes

Given Mali’s strategic importance in West Africa as a major producer and exporter of small ruminants, global eradication of PPR will be possible only if Mali succeeds in its eradication effort. And given LCV’s strategic location within the region and its pioneering experience in utilizing the thermotolerant PPR vaccine, with some upgrading, the Laboratory can and should enlarge its role as a major vaccine supplier to neighboring countries.

Potential impacts

Conclusion

Today’s PPR eradication campaign is inspired by the successful global effort to eradicate a related Morbillivirus that caused rinderpest. That plague of cattle and wild ungulates regularly wiped out whole herds and devastated communities over several thousand years, infamously killing, in the 1890s, an estimated 80–90% of all cattle in eastern and southern Africa, and consequently starving to death one-third of the population of Ethiopia and two-thirds of the Maasai people of Tanzania. Only the second disease (after human smallpox) to be eradicated globally, rinderpest achieved its official eradication status in 2011. One of the underlying success factors for its global eradication was the development of a thermotolerant vaccine.

FAO and WOAH have provided guidelines and blueprints for PPR’s global eradication by vaccination. With OvipestePlus, Mali has the opportunity to eradicate a livestock disease that is now devastating its economy and poorer communities. Achieving success by 2030 will depend on next-level scaling, vaccine equality, sustained advocacy, and international collaboration.

As the epicenter of intense efforts to scale a new thermotolerant PPR vaccine, Mali also has the potential to expand its capacity to serve its neighboring countries. It can—and should—help lead the charge to eradicate goat plague from the earth.

This article was written by Michel Dione, Abdrahmane Wane, Ahmadou Sow, Guy Ilboudo, Nicoletta Buono, and Ijudai Jasada, of the International Livestock Research Institute (ILRI); Oumar Kantao and Cheick A.K. Sidibe, of Mali’s Central Veterinary Laboratory; Cheick Fomba, of Mali’s General Directorate of Veterinary Services; Anta Diagne, of the World Organization for Animal Health in Mali; Eugene Koffi Kouassi, of the Regional Animal Health Centre in Mali; and Jan Low, of JWLOW Ltd., in Kenya.