Britain is preparing to become the first country to roll out the Pfizer-BioNTech COVID-19 vaccine this week, initially making the shot available at hospitals before distributing stocks to clinics, the government said on Sunday.

The first doses are set to be administered on Tuesday, with the National Health Service giving top priority to vaccinating the over-80s, front-line health care workers and care home staff and residents.

Britain gave emergency use approval for the vaccine developed by Pfizer and BioNTech last week — jumping ahead in the global race to begin the most crucial mass inoculation program in history.