A third Covid vaccine has been approved for use in the UK.
It is made by US company Moderna and works in a similar way to the Pfizer one that is already being offered on the NHS.
The UK has ordered an extra 10 million doses of this vaccine, taking the total order to 17 million, but supplies are not expected to arrive until spring.
Around 1.5 million people in the UK have had at least one dose of Covid vaccine so far.
That includes almost a quarter of those aged over 80 in England.
Vaccines are being given to the most vulnerable first, as set out in a list of nine high-priority groups, covering around 30 million people in the UK.
The prime minister has said the aim is to vaccinate 15 million people in the UK by mid-February, including care homes residents and staff, frontline NHS staff, everyone over 70 and those who are clinically extremely vulnerable.
Health and Social Care Secretary Matt Hancock said: “This is further great news and another weapon in our arsenal to tame this awful disease.”
The UK had originally ordered 7 million doses of the Moderna jab, but has increased this by 10 million to get even more people immunised as quickly as possible.
In total, the UK has now ordered 367 million doses of vaccines to protect against Covid-19.