A Revolutionary Solar Fridge Will Help Keep COVID Vaccines Cold In Sub-Saharan Africa

FREETOWN, Sierra Leone — President Biden this month announced plans to ship a half a billion doses of the Pfizer vaccine to the 100 lowest income countries in the world. That would include Sierra Leone and many other sub-Saharan African nations.

But there's a looming problem. The Pfizer vaccine needs to be stored at minus 100 degrees Fahrenheit. In all of Sierra Leone, population 7.8 million, only one functioning freezer can offer storage at that temperature. It's housed in a complex at the Ministry of Health's medical warehouse compound in the capital Freetown. It's only slightly larger than a residential fridge, and it's already being used to store an Ebola vaccine which requires similar temperatures.

"It's definitely a nice gesture by President Biden," says Dinsie Williams, a Sierra Leonean biomedical engineer. "But we do have to think about everything else along the supply chain of how they keep those vaccines at the right temperature for a long period of time and then having people access them regardless of where they live."

Health officials in Sierra Leone say they're likely to request other vaccines such as AstraZeneca and Johnson & Johnson, which only need to be stored in standard refrigerators.

But in Sierra Leone and other sub-Saharan African countries, even ordinary refrigeration is a challenge. Only about 1 in 4 Sierra Leonean households have power. The rate is down to about 6% in rural parts, according to Sustainable Energy for All, a collaboration between the United Nations and the World Bank.

"Access to refrigeration is very limited," says Williams. "Because there's very limited access to electricity, at least stable electricity, in most parts of the country."

Other countries in the region are only slightly better off: only 28% of health facilities in Sub-Saharan Africa have reliable power supplies.

A revolutionary new generation of solar fridges may prove crucial in the upcoming efforts to immunize Sierra Leoneans against COVID. UNICEF and GAVI, the vaccine alliance, have been pushing to deploy these fridges to health clinics in Africa for childhood immunization programs.

A child is inoculated with a vaccine at the Songo Health Clinic in Sierra Leone.

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Rather than store electricity in batteries to power them through the night, these so called "direct-drive" systems store coldness. They are so efficient and so well-insulated that they can stay cold for 3 days even if the solar panels aren't supplying power. And the lack of batteries makes them far simpler to operate and maintain.

Saffa Kamara, an immunization officer with UNICEF in Sierra Leone, raves about these solar fridges.

He says they are "far, far better" than earlier solar models, gas-powered ones or even conventional fridges run off a generator.

"All we need at the moment is [the new] solar refrigerators so we can reach the hardest areas, the most difficult communities and immunize the children," he says. And they could also be the solution to the COVID vaccine storage problem as well, particularly for the vaccines that don't require ultra-cold temperatures.

The Songo Health Clinic in Northern Province is one of the many government health facilities across Sierra Leone that doesn't have electricity.

Mariama Koroma, who runs the clinic, says at times they have to deliver babies by flashlight. But they do have a solar fridge for their vaccines — one of 371 in the country.

Mariama Koroma shows a revolutionary type of solar-powered refrigerator in the Songo Health Clinic, used to store vaccines. They don't use batteries but use a "direct-drive" system to store coldness.

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"All the vaccine that we are supposed to use in Sierra Leone, we have here," Koroma says peering into the thick-walled refrigerator.

Sierra Leone is in the early stages of doing COVID vaccinations. So far only a tiny portion of the population has been immunized. And the limited COVID doses haven't yet been distributed to small clinics like Koroma's in Songo.

But as more vaccines do arrive, the new solar freezers will be crucial to allow doses to be distributed, stored and eventually administered to people in many parts of Africa with limited or no electricity — an urgent task as COVID-19 cases rise in Africa.

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