Ultra-cold Freezing Presents Next Challenge in Covid Vaccine Race
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 20°C, 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 70°C.
“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.
“即使到今天，很多国家的政府还没有做好准备。”B Medical Solutions副首席执行官耶赛尔·多西（Jesal Doshi）表示。这家总部位于卢森堡的冷冻箱生产商已将500至1000台的正常年产量增加两倍多，其700升规格的冷冻箱眼下需求巨大，这些冷冻箱用于实验室和医院，可存储多达28万剂疫苗。
Ultra-cold freezer technology, while sophisticated, has been around for decades. A typical minus 80°C 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 80°C 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.”
“尽一切可能让疫苗小瓶或披萨盒始终在零下80摄氏度走完冷链，是非常了不起的事情。”总部位于俄亥俄州的制造商、客户包括辉瑞、强生（Johnson & Johnson）和联合包裹（UPS）的Stirling Ultracold的首席执行官达斯蒂·坦尼（Dusty Tenney）表示，“以前从未真正做到过这样的事情，从未以这样的规模。”
Mr Tenney said orders for ultra-cold freezers, which can achieve temperatures from minus 20°C to minus 86°C, 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.
除了较大的“医院规格”冷冻箱外，许多供应商还表示，用于药房的较小型“柜台下”100升冷冻箱的订单也出现激增。海尔生物医疗英国公司（Haier Biomedical UK）总经理理查德·贾弗拉托（Richard Jafrato）介绍说，这些较小的冷冻箱可容纳约4500个小瓶，每个小瓶包含5剂BioNTech-辉瑞疫苗。
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 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.