With the second wave of COVID-19 now proving even more serious than the first, the rapid development of vaccines to provide protection has been very welcome. The unprecedented speed with which they have appeared — and continue to be developed — is testament to the global threat posed by the virus.

However, producing the number of vaccine doses required is only half the battle. The infrastructure needed to support distribution is very complex: for example, there needs to be enough glass vials to hold the vaccines and enough staff trained to administer them.

A secure cold chain also needs to be in place to keep the vaccines refrigerated at the requisite temperature throughout their journey, from laboratories to end recipients.

This is a challenge even in developed countries with extensive medical and electricity networks. In many developing countries, such networks are very fragmentary or intermittent. Often the greatest problems are at the furthest end points of the chain, where mains electricity to power refrigerators can be non-existent.

It was to help solve this problem that Dulas pioneered solar-powered vaccine refrigerators back in the 1980s. Having been used in the years since then to support immunisation programmes for a range of diseases, this technology now provides a tried and tested way to store COVID-19 vaccines safely, even in the most remote locations.

Our latest generation of solar direct drive (SDD) refrigerators come in a range of sizes, up to the 132 litres capacity of the VC200SD model. All have WHO PQS (Performance Quality and Safety) accreditation and are CCEOP eligible. (CCEOP is the Cold Chain Equipment Optimization Platform established in 2015 by Gavi, the Vaccine Alliance, to strengthen global vaccine supply chains.) They have been proven to provide dependable operation in remote locations across the world.

For locations where mains electricity exists but is unreliable, we supply refrigerators like our VC225ILR. Ideal for large health facilities, this model has 184.5 litres capacity and is supplied with a dedicated power regulator and voltage stabiliser.

All our fridges have a long holdover, meaning they keep vaccines like the COVID-19 one developed by Oxford/Astra Zeneca refrigerated for a number of days, even if there are low levels of sunlight or the mains supply is interrupted. Just as important as keeping vaccines cool is preventing most of them from freezing, so our fridges are also fitted with freeze-free technology that stops this happening.

Operation can be monitored remotely through Vaccine Guard, a system that automatically measures and records the temperature every ten minutes and sends immediate alerts via SMS and/or email if the temperature varies from the specified range.

Getting our vaccine refrigerators to where they are needed can be another challenge, but with Dulas it’s all part of the service. Alongside our extensive network of partners, we have decades of experience in ensuring our fridges are delivered, installed and maintained in perfect working order.

In the fight against COVID-19, Dulas refrigerators offer a proven solution for storing vaccines in remote locations, so nobody has to miss out on immunisation.