For a few hours this week, we were given an insight into the closely-guarded secret at the centre of the UK’s vaccination programme.
It came courtesy of the Scottish government, which published its vaccination plan on Wednesday.
The plan included detailed figures for the number of vaccines that would be supplied to Scotland by the UK each week until the end of May.
The UK government has promised to offer COVID-19 vaccines to 15 million vulnerable people by the middle of February.
More than a month into the programme, it’s managed to give 3.2 million people a jab. By international standards this is impressive. What’s more, according to today’s figures, the daily rate is now close to what is needed for the government to hit its goal.
Assuming that there are no problems with the supply or the delivery, Scotland will have enough vaccine to offer two doses to every adult in the country by the middle of July.
In practice, not everyone will take up the offer of a vaccine so these targets could be reached even faster. The Scottish government itself is expecting 80% take-up; our numbers are based on 100% take-up.
We can also use these numbers to estimate when the UK as a whole will get its vaccines. This involves making some assumptions, so any figures should be taken with a pinch of salt.
But the results these numbers produce explains why, behind the scenes, ministers are so confident about the rollout of the vaccine.
Of course there are many things that could go wrong from here. Raw materials can run short. Vaccines can get lost or wasted.
But there are reasons to be optimistic.