Africa’s Essential Medicines Face a Heat-Stability Test
Unitaid’s US$10.9m SHIELD project will study heat and humidity risks to medicines in Kenya, Nigeria and Senegal, with validation in South Africa.
Unitaid has announced a US$10.9 million initiative to investigate how heat and humidity affect selected medicines, diagnostics and other health products as they move through real supply chains. The four-year Safeguarding Heat Stability in Essential Life-Saving Drugs and Diagnostics project, known as SHIELD, will run from 2027 to 2030. Its field research will include Kenya, Nigeria and Senegal, with findings tested for transferability in South Africa. India and Brazil are also part of the work.
The investment is a research programme, not a finding that essential medicines in African clinics have already been damaged. The project will first measure the conditions products encounter during storage, transport and delivery, then test selected products in laboratories and combine the evidence with climate projections. That distinction matters: the presence of high ambient temperatures does not by itself prove that a particular medicine or diagnostic has lost quality. Product stability depends on its formulation, packaging, exposure duration and the storage conditions set by its manufacturer.
What SHIELD will investigate
Unitaid says the project will examine selected products relevant to HIV, tuberculosis, malaria, and maternal and child health. Led by the United States Pharmacopeia, the consortium includes ACCESS Health International, VillageReach and Wits University Planetary Health Research, with Ecovamed and Brazil’s National Institute for Space Research among its technical partners. Governments, regulators, health workers and communities are expected to contribute in the six participating countries.
The study is designed to answer several practical questions. Which products are most exposed to heat and humidity in current supply chains? How often do conditions exceed the limits those products are approved to tolerate? Which risks may grow over the next 20 to 30 years as climate conditions change? And what interventions would reduce risk without making essential health products less accessible or more expensive? The project has not yet published results, product lists or country-by-country implementation plans.
Why the supply chain matters
Medical products can pass through ports, warehouses, regional depots, vehicles and clinics before they reach a patient. Each point has different infrastructure and monitoring capacity. Refrigerated products depend on a functioning cold chain, while many medicines and diagnostics have other labelled limits for temperature, moisture, light or handling. A short exposure and a prolonged one may not have the same effect; neither should be assumed to make every product unsafe without testing and technical assessment.
The World Health Organization’s good storage and distribution guidance stresses that conditions stated on product labels should be maintained through storage and distribution. In practice, keeping records of temperature and humidity can help health agencies identify where excursions occur, distinguish a one-off problem from a recurring route or facility issue, and decide whether a product needs assessment. Data only becomes useful when it leads to clear procedures for quarantine, quality review and replacement where required.
For African health systems, the issue reaches beyond warehouse refrigeration. Long transport routes, unreliable electricity, limited climate control and hot or humid environments can complicate storage at multiple stages. Yet the answer is not automatically to install more refrigeration everywhere. Cooling equipment has purchase and maintenance costs, needs dependable power and trained staff, and may be unnecessary for products that remain stable within their labelled conditions. Evidence can help target investment where it brings the greatest protection.
From measurements to workable policy
SHIELD plans to measure exposures during storage, transport and delivery in India, Kenya, Nigeria and Senegal, then validate the findings in Brazil and South Africa to assess whether results transfer to other settings. This design may help separate country-specific problems from common patterns, but local context will still matter. A hot coastal route, an inland warehouse and a rural clinic may face different combinations of temperature, humidity, transport time and power reliability.
Unitaid says the findings could inform packaging, temperature monitoring, storage and distribution practices, product development, procurement decisions, regulation and global guidance. Those choices involve trade-offs. Better packaging may reduce exposure but add cost or waste. More monitoring can reveal problems, but does not itself prevent them. Procurement rules may need to reward products suited to actual delivery conditions while maintaining quality standards and competition. Changes in product labels or stability limits would require robust scientific and regulatory review.
That is why the participation of health workers, regulators and communities is important. Frontline staff can identify where records are missing or procedures are unrealistic; regulators can determine how evidence should influence oversight; communities can help ensure that proposed changes do not disrupt access. The project says it will prioritise solutions led by the Global South, an approach that can help keep research connected to the places where products are stored and used.
What African stakeholders should watch
The next milestones are not simply the release of a final report in 2030. Useful interim information would include which products and routes are studied, how samples are selected, what monitoring tools are used and how results are shared with country authorities. It will also be important to see whether the programme distinguishes between exposure measurements, laboratory stability tests and actual clinical or service outcomes. Each answers a different question.
For health ministries and procurement agencies, the most immediate value may be a clearer map of weak points: where temperature control is difficult, which products are sensitive, what monitoring is feasible and which solutions are cost-effective. That could support better investment in storage, packaging, transport and contingency planning. But any changes should preserve the principle that products are handled according to approved manufacturer conditions and assessed by qualified authorities when excursions occur.
Climate resilience in health is often discussed in terms of hospitals, power systems and heat-related illness. SHIELD draws attention to another layer: whether essential products retain their quality as they travel through a changing climate. Its African reach makes the project relevant to national supply chains, but the announced funding does not yet show that risks have been reduced. The test will be whether measured evidence leads to practical, affordable changes that protect product quality without interrupting access to treatment and diagnosis.
