Demand for ultra-cold storage freezers has spiked as governments and manufacturers prepare to ship Covid-19 vaccines around the world and along the so-called last mile to those most vulnerable to the disease.
Unique characteristics of the two leading Covid-19 vaccines mean they both have to be transported frozen. The shot developed by US biotech Moderna, currently under regulatory review in the US and the EU, can survive for six months at minus 20C, the temperature of a standard domestic freezer. The vaccine developed by Pfizer and Germany’s BioNTech, approved for use in the UK this month, must, in contrast, be transported at minus 70C.
“A lot of governments even today are not prepared,” said Jesal Doshi, deputy chief executive at B Medical Solutions. The Luxembourg-based freezer producer has more than tripled its normal annual production of 500 to 1,000 units, recording massive demand for its 700L unit, used in laboratories and hospitals, which can store up to 280,000 vaccine doses.
Ultra cold freezer technology, while sophisticated, has been around for decades. A typical minus 80C freezer works through a cascade refrigeration system, which combines two independent compressors to reach lower temperatures. A household freezer has only one compressor without a heat exchanger and uses different gases.
The BioNTech-Pfizer and Moderna vaccines have to be kept so cold because of the “lipid nanoparticles” used to enclose and protect the fragile genetic instructions that trigger the immune response. These microscopic droplets of oily liquid — about 0.1 micron in diameter — require cold storage to prevent them from degrading.
Politicians, medical advisers and manufacturers have all stressed the practical hurdles in distributing BioNTech-Pfizer’s vaccine in particular, with UK prime minister Boris Johnson warning of “immense logistical challenges” in moving the vials, which are shipped in specially designed “pizza boxes”.
“Doing everything to keep vials or a pizza box at minus 80C through the cold chain is a very significant feat,” said Dusty Tenney, chief executive of Stirling Ultracold, an Ohio-based manufacturer that counts Pfizer, Johnson & Johnson and UPS among its customers. “It has never been really done before — never at this scale.”
Mr Tenney said orders for ultra-cold freezers, which can achieve temperatures from minus 20C to minus 86C, had more than trebled in the last three months of the year compared with pre-pandemic levels, and stretched lead times to as long as six weeks.
In addition to larger “hospital-sized” units, many suppliers have also received a spike in orders for smaller “undercounter” 100L freezers for use in pharmacies. The smaller units can hold about 4,500 vials, each containing 5 doses of the BioNTech-Pfizer vaccine, according to Richard Jafrato, general manager of Haier Biomedical UK.
Stirling Ultracold is also producing a 25L portable freezer that can be powered by a vehicle battery, enabling the BioNTech-Pfizer jabs to be transported, if necessary, into remote locations.
Publicly available contracts show the UK government has spent close to £4m on ultra-cold freezers, which can cost between £3,000 and £12,000 each. In the US, companies are gearing up to vaccinate their workforces, with carmaker Ford buying freezers in preparation.
Some smaller suppliers said they had already sold out of ultra-cold units until March. However, freezer-related delays to vaccination programmes are thought to be unlikely after large-scale producers such as China’s Haier and Japan’s KKR-backed PHC Holdings increased output earlier in the year.
Despite the challenges, installing the systems needed to transport the vaccines should be possible in both developed and developing economies, said Mr Doshi at B Medical. “The challenge isn’t [of] the magnitude that everyone’s talking about, it’s not that difficult,” he said, adding that even delivery to remote, poor communities could be achieved.