Liz Breen, University of Bradford and Sarah Schiffling, Liverpool John Moores University

The Pfizer/BioNTech vaccine has just been approved for widespread use in the UK and the government has ordered 40 million doses - enough to vaccinate 20 million people. The first 800,000 doses are expected to be delivered to the UK in the next few days.

The Moderna and Oxford/AstraZeneca vaccines also appear to be close to gaining approval by regulatory authorities. The vaccines promise billions of people around the world a return to normality as the pandemic is brought to an end.

After the great effort put into developing and testing these vaccines, another huge task lies ahead: the logistics of vaccine distribution.