The Pfizer/BioNTech coronavirus vaccine will be rolled out next week following its approval in the UK.
Britain became the first country in the world to approve the jab on Wednesday, with Boris Johnson hailing the work of the Medicines and Healthcare products Regulatory Agency (MHRA) which gave it the go-ahead.
The prime minister said: “It’s fantastic. The vaccine will begin to be made available across the UK from next week.
“It’s the protection of vaccines that will ultimately allow us to reclaim our lives and get the economy moving again.”
These are the key numbers behind the vaccine rollout which comes just 23 days since Pfizer/BioNTech published the first data from their final-stage clinical trial.
Watch: UK first in the world to approve Pfizer/BioNTech coronavirus vaccine
21: The number of days between doses
In total two injections will be given 21 days apart.
Patients will start to gain immunity after the first dose but full protection does not occur until a week after the second booster jab.
800,000: The number of doses the UK says it has of the vaccine
Health secretary Matt Hancock said he expects to begin receiving the first shipment of 800,000 doses from Pfizer’s manufacturing centre in Belgium “within days”, and people will begin receiving jabs as soon as the NHS gets the vaccine.
Doses everywhere are scarce, and initial supplies will be rationed until more is manufactured in the first months of next year.
The speed of the rollout depends on how fast Pfizer can manufacture and deliver the vaccine.
40 million doses ordered
Johnson said last month that UK had ordered 40 million doses of the Pfizer vaccine – enough for just under a third of the population as two shots of the jab are needed per person to gain immunity.
The vaccine is 95% effective
Pfizer/BioNTech said last month final results from the late-stage trial of its COVID-19 vaccine showed it was 95% effective.
The companies said efficacy of the jab was consistent across age and ethnic groups, and there were no major side effects, a sign that the immunization could be employed broadly around the world.
40,000 people involved in trials for vaccine
About 40,000 people were involved in the vaccine trials, with half receiving the vaccine and half receiving a placebo, with adverse effects only lasting for around a day.
Vaccine needs to be store at -70C (-94F)
Distribution would be a challenge given the vaccine must be shipped and stored at -70C (-94F), the sort of temperature typical of an Antarctic winter.
Pfizer has said the shots can be kept in thermal shipping boxes for up to 30 days, from up to 15 days previously guided.
Afterwards, the vaccine can be kept at fridge temperatures for up to five days.
Professor Sir Munir Pirmohamed, chairman of the Commission on Human Medicine Expert Working Group, said while it had to be stored at - 70C, advice was being issued to the relevant agencies on how it could be deployed safely.
357 million vaccine doses ordered by the UK
Overall the UK has access to 357 million doses of vaccines from seven developers, according to the government.
It has also secured 100 million doses of the vaccine developed by AstraZeneca and Oxford University and has targeted a rollout to begin before Christmas.
Watch: How England's new three-tier COVID system will work