The UK has become the first country to approve the Pfizer-Bio-n-Tech Covid-19 vaccine -- making the first 800 thousand doses available next week. While this is being hailed as the harbinger of the pandemic’s end, it has come with costs -- costs that many are willing to overlook in exchange for a promised return to normality. Melisa Idris and Sharaad Kuttan speak to Sanjeev Krishna, Professor of Molecular Parasittology and Medicine, Institute of Infection and Immunity in London.