1.8ml of Sodium chloride is added to a phial of the Pfizer/BioNTech COVID-19 vaccine concentrate ready for administration at Guy’s Hospital at the start of the largest ever immunization progran in the U.K.’s history on December 8, 2020 in London, United Kingdom.Victoria Jones – Pool | Getty ImagesLONDON — Two hospitals in the U.K. are actively using blockchain technology to help maintain the temperature of coronavirus vaccines before administering them to patients.The National Health Service facilities in South Warwickshire, England, are using tech developed by U.K. firm Everyware and U.S. organization Hedera Hashgraph. Everyware uses sensors to monitor equipment in real-time, while Hedera is a blockchain consortium backed by the likes of Google and IBM.Though originally created as the digital ledger underpinning bitcoin, blockchain has since been adapted by various industries for applications outside the realm of finance. IBM and Walmart, for instance, have used blockchain to trace food supply chains and identify potential contamination.Tom Screen, technical director at Everyware, told CNBC that its sensors would monitor the temperature of refrigerators storing vaccines. It then transmits the data to its own cloud platform where it is encrypted and then passed on to Hedera’s blockchain network.The point of this operation is to keep a tamper-proof digital record of temperature-sensitive vaccines, like the ones developed by Pfizer and BioNTech. The hospitals would, in theory, be able to pick up on any irregularities in the storage of the vaccines before administering them to patients.Pfizer’s vaccine must be stored at subzero temperatures (-70 degrees Celsius), and can only last at two-to-eight degree Celsius conditions for up to five days, creating big hurdles for the logistics in distributing it.The vaccines developed by Moderna and Oxford-AstraZeneca, however, can be stored at temperatures that are within the reach of the average home refrigerator for longer.Blockchain saw much hype back in 2017, as the value of cryptocurrencies like bitcoin skyrocketed. It led to several projects from major companies including IBM and Walmart, as well as governments, lured in by the promise of replacing various old, paper-based processes for record keeping.Today, the buzz around blockchain seems to have died down, with barely any trials and products based on the technology being announced by big corporates.Asked why blockchain was needed rather than a regular database, Everyware’s Screen said “data held in a private database can be verified against the state of data recorded on the public ledger.””The benefits of an immutable ledger to verify the validity of data as close to the source as possible has a positive effect on the accuracy of downstream analytics, where any error in source data would be magnified in output datasets,” he said.Everyware competed in an open tender process involving other bidders to provide its services to the South Warwickshire NHS Foundation Trust, Screen said.