The challenge of the COVID-19 vaccines cold chain in...

The World Health Organization (WHO) recently announced that the UN-led joint COVAX initiative has started shipping about 90 million doses of COVID-19 vaccines to Africa starting in February 2021. As production capacity increases and more vaccines become available, the COVAX program aims to vaccinate at least 20% of Africans by providing up to 600 million doses by the end of 2021 (1). To complement the COVAX objectives, the African Union has secured 270 million additional doses of vaccine for the continent. At least 50 million doses will be available from April to June 2021 from Pfizer, AstraZeneca and Johnson & Johnson (2).

Even if the provision of a large number of vaccines is secured, there is an enormous logistical challenge: how to store and transport temperature-sensitive vaccines to places without reliable electrical and refrigeration infrastructures?

According to Brookings (3), about only 22 out of the 54 African countries have a working cold-chain system for vaccines requiring storage at 2°C to 8°C, such as the AstraZeneca vaccine. However, some of the COVID-19 vaccines – such as Pfizer and BioNTech vaccines – require a storage temperature of around -70°C , while most African countries do not have the cold chain infrastructure necessary for these temperature levels. (4)

Senegal, for example, does not have the capacity to store COVID-19 vaccines at ultra-low temperatures, according to the head of the country’s vaccination programme. A lack of cold storage means Senegal is only capable oring vaccines developed by AstraZeneca and by China or Russia over the long term. (5)

In addition, the efficacy of AstraZeneca’s vaccine against certain variants of COVID-19 is being questioned, which has led South Africa – where the 501Y.V2 variant is dominant – to suspend its vaccination campaign with this vaccine. As a result, South Africa says it has secured 20 million doses from Pfizer, with deliveries starting in the second quarter (5). Pfizer specified that it will allow “direct shipment to the point of vaccination in an isothermal shipper that will maintain the ultra-low temperature required for up to 10 days unopened” (6).

More generally, the major problem in Africa is access to the electricity grid. According to the IEA, nearly 600 million people in Africa live off the grid, and rural clinics oftenhe not connected to the grid (7).

Solar refrigeration can play an important role in this context. In this respect, Gricd, a small Nigerian startup, has built portable solar-powered cold boxes for transporting vaccines, which can be maintained at -20°C and can be remotely controlled and monitored in real time. The solar-powered batteries have sufficient autonomy to maintain a stable internal temperature for up to a week, according to the company. The product has been certified by the Standards Organisation of Nigeria and is in the process of obtaining PQS certification from the WHO.

The boxes range in size from 15 to 100 liters, with the smallest being able to carry about 200 doses of vaccine. The 15-liter box is specifically designed for the "last mile" – the final stage of the vaccines’ journey, whichis also the biggest gap in the vaccine cold chain in rural Africa. (8)

Sources:

The challenge of the COVID-19 vaccines cold chain in Africa