As the third year of the pandemic begins, we know it won’t be over until people everywhere receive the vaccine—and maybe not even then. But it’s not just a matter of manufacturing and shipping enough vaccines for everyone. Several COVID-19 vaccines require refrigeration to maintain their efficacy. That’s a problem where there’s no electrical grid—or where it isn’t reliable. How do you maintain the cold chain to make vaccines available in Africa?
Some [low- and lower middle income countries] are facing serious challenges in vaccine deployment. Constraints related to storage, cold chain capacity, and trained vaccinators are exacerbated in some cases by doses arriving with short shelf lives and without adequate lead time and shortages in ancillary supplies (such as syringes, safety boxes, and dilutants), with challenges to plan and finance vaccination campaigns in a timely manner.—World Health Organization, 22 December 2021
The cold chain
It’s not only COVID vaccines that must keep cold to remain effective. In the 1980s, a group of health professionals determined to vaccinate all the world’s children against six deadly diseases. In 1988 alone, tetanus, whooping cough, measles, and tuberculosis killed more than 3 million children. Polio disabled another quarter million. These, along with diphtheria, became the focus of an international campaign.
Naturally a project this ambitious faced many obstacles. Countries at war had to agree to stop fighting long enough to gather the children and administer the vaccines. Parents had to get the information about what was happening and where to go. They needed to hear from community leaders they trusted so they’d be willing to participate. Vaccines and other supplies had to travel over bad roads—or no roads—in a timely manner. Clinics had to be set up and health workers trained. But the biggest obstacle was the need to keep the vaccines cold continuously.
The cold chain always presents a formidable obstacle, whose demands are inflexible and dominate all those involved in childhood immunization, especially since the journey of the vaccine from manufacturer to child may take at least a year. If purity rules the production process, temperature rules from that point on….If a campaign fails locally, or a major epidemic occurs after immunization, failure of the cold chain is always the first suspect.—June Goodfield, A Chance to Live, 1991
Solar refrigerators may seem like an oxymoron, but they’re the ideal way to maintain the cold chain when electricity isn’t reliable. Although they’re relatively expensive, they’re reliable and easy to maintain. In northern Africa, they combine with a low-maintenance mode of transport—camels.
In the Sahara it is now commonplace to see camels with a solar panel strapped across their saddles to keep cool the vaccine pack boxes strapped on either side.—June Goodfield, A Chance to Live, 1991
Dr. Winston Oluwole Soboyejo, then at Princeton University, developed solar panels for camels to transport medical supplies to remote clinics. He and his team worked with camels at the Bronx Zoo to design frames to hold the solar panels and medical supplies. However, once on the ground in Kenya, they found that not all camels are alike. The camels at the Bronx Zoo were bigger and hardier than their African cousins. The engineers had to make the frames lighter and adjustable to fit around each camel’s hump. They also found, though, that it isn’t necessary to optimize the angle of the solar panel. Just about any angle will do where the sunlight is so intense.
Video: Dr. Soboyejo explains how solar power and camels help make medical clinics and vaccines available in Africa.
Making COVID vaccines available in Africa
Now a young Kenyan engineer, Norah Magero, has made solar refrigerators smaller—small enough to fit on the back of a bicycle or motorbike. Initially she wanted to source the components locally, but that proved impractical, so she contracted with a firm in China. But after waiting four months for the prototype, she found the result expensive and disappointing. So she and her team started again, looking for components she could obtain in Kenya.
While all this was going on, the COVID outbreak lent new urgency to the project. Kenya is developing its electrical grid, but there are still rural areas where it either hasn’t reached yet or isn’t reliable. Ms. Magero’s Vaccibox is helping to fill the gaps in distribution so that no one is beyond the reach of a COVID vaccine.
Video: Norah Magero explains how solar refrigerators on bicycles can make COVID-19 vaccines available in Africa.