It’s a familiar sight: nurses retrieve vaccines from fridges for use while patients wait anxiously. Vaccines are extremely sensitive to temperature fluctuations, the slightest of which can have wreak havoc on the vaccines. That’s why the importance of the vaccine cold chain cannot be overstated, and why vaccine fridges are indispensable equipment for hospitals. UK-based renewable energy company Dulas has developed a solar-powered vaccine fridge that does not require battery or external power even when transporting vaccines across long distances. For remote regions’ vaccine needs, Dulas’ solar fridge is a godsend.
For vaccines to maintain their effectiveness, they must be stored in temperatures between 2-8°C, which means that an uninterrupted supply of electricity for the sake of maintaining temperature is needed during transportation. This in turn presents a great challenge for areas without a steady supply of electricity, such as remote villages and deserts.
In light of this, Dulas and vaccine alliance Gavi are currently engaging in a multi-year collaboration in an effort to develop solar refrigeration systems to facilitate vaccine transportation to remote areas in Africa, Asia, and South America. The systems will also be used to transport COVID-19 vaccines, as they become available, to meet local medical demands.
Dulas’ vaccine fridges come in battery and non-battery powered varieties, with the former meant for areas without sufficient sunlight and thus able to keep vaccines chilled at night. Even so, Dulas’ non-battery fridges are capable of maintaining a constant temperature via the use of non-corrosive phase change materials. According to Ruth Chapman, Dulas’ managing director, the non-battery fridges contain a special liquid that is frozen via solar energy and keeps constant temperature within the fridge during times without sunlight.
One of Dulas’ co-founders, Guy Watson, said he initially drew inspiration from his participation in humanitarian aid in an Ethiopian war zone in 1984, where he found it difficult to supply blood during surgeries due to the lack of refrigeration systems on the front lines. At the time, the medical teams had to settle for makeshift measures such as finding matching blood types from those present on the front lines (including from others in need of surgical operation themselves). Thus, Watson originally conceived of an idea to create a solar fridge.
Dulas shipped nearly 2,000 vaccine fridges to countries such as Myanmar and Sierra Leone from 2015 to 2017. The company has recently developed a monitoring system called Vaccine Guard that keeps tabs on the temperature of vaccines inside the fridge and gives off warnings should said temperature deviate from normal levels.
The UK government has pledged £330 million to Gavi for the next five years. According to Seth Berkley, CEO of Gavi, the funding will go towards not only protecting countless children from infectious diseases, but also helping governments rebuild and recover their healthcare systems in the post-COVID era.