First batches of COVID vaccine delivered to UK hospitals

Meanwhile, a batch of coronavirus vaccines arrived at a south London hospital on Sunday, days after the U.K. authorized Pfizer and BioNTech's jab for emergency use. Around 800,000 doses of the vaccine were expected to be in place for the start of the immunization program on Tuesday.

Delivering the Pfizer-BioNTech vaccine is complicated because it needs to be stored at super-chilled temperatures: about minus 70 degrees Celsius. Fortunately, the vaccine is stable at normal refrigerator temperatures, between 2 and 8 degrees Celsius, for a few days, meaning it can be stored locally. After defrosting the vaccine, which takes a few hours, additional time is required to prepare it to be given in a shot. In trials, the Pfizer-BioNtech jab was shown to have around 95% efficacy.