Why the delay? The nations waiting to see how Covid vaccinations unfold

A medical worker receives an injection with a dose of the Pfizer-BioNTech Covid-19 vaccine in Mexico Photograph: Daniel Becerril/Reuters

source https://www.theguardian.com/world/2021/jan/08/why-the-delay-the-nations-waiting-to-see-how-covid-vaccinations-unfold