The NHS needs to vaccinate two million people a week to reach Boris Johnson's goal of 13.2 million coronavirus jabs for the top priority groups by mid-February.
About 300,000 doses are currently being given every week - a figure that must be averaged every day for the next 41 days to hit the Prime Minister's target - although the effort is being ramped up.
At a rate of 300,000 a week, it would take until October to vaccine all 13.2 million people. An online calculator suggests healthy Britons who opt for a jab won't receive one until February 2022 at a rate of 1 million doses per week.
The PM's target is an ambitious one and there are serious doubts about whether the Government can really pull it off given the slow start to the rollout