The UK has become the first country in the world to approve the Pfizer/BioNTech coronavirus vaccine, paving the way for mass vaccination.
Britain's medicines regulator, the MHRA, says the jab, which offers up to 95% protection against Covid-19 illness, is safe to be rolled out. The first 800,000 doses will be available in the UK from next week, Health Secretary Matt Hancock said. People should wait to be contacted by the NHS, he added.
Elderly people, those in care homes and some NHS staff will be prioritised first - although more details on the priority list is due later.
Additionally, the order in which people will get the jabcould also depend on how easily the jab can be rolled out. The Pfizer jab needs to be stored at -70C, which is easier to be stored in hospitals rather than in the community, Mr Hancock.
The vaccine is given as two injections, 21 days apart, with the second dose being a booster. It takes a few weeks for immunity to build.
The UK has already ordered 40 million doses of the free jab - enough to vaccinate 20 million people. The doses will be rolled out as quickly as the company in Belgium can make it, Mr Hancock said, with the first load next week and then "several millions" throughout December but the bulk of the rollout will be next year.
Around 50 hospitals are on stand-by and vaccination centres - in venues such as conference centres or sports stadiums - are being set up now.
But experts said people still need to remain vigilant and follow rules to stop the virus spreading - including with social distancing, face masks and self-isolation.