The UK has ramped up the rollout of COVID-19 vaccinations with the opening of seven new centres.
Prime Minister Boris Johnson wants the UK to inoculate 15 million vulnerable people by mid-February.
Large-scale vaccination centres opened in Bristol, Manchester, London and Newcastle on Monday, with more planned in the coming months.
They have been made possible by the approval of the Oxford-AstraZeneca jab, which, unlike the Pfizer one, does not need to be kept at ultra-low temperatures.
It comes as the UK battles a resurgence of cases due to a more transmissible variant of the coronavirus.
"This is a very perilous moment because everybody can sense the vaccine is coming in," Johnson said, adding that there was no time for complacency.
"The worst thing now would be for us to allow success in rolling out the vaccine programme to breed any kind of complacency in the state of the pandemic," Johnson added.
There will be 50 mass vaccination centres by the end of the month, Johnson added on Monday.
On top of that, hundreds more GP and hospital services will open as well, taking the number of places where people can receive a vaccine to 1,200
It's part of a larger vaccination strategy to inoculate most of the population by the autumn, the government has said in a 47-page vaccine delivery plan.
Around two million people have already been vaccinated since the vaccinations started in December.
The UK is one of the worst-hit countries in Europe due to the pandemic with more than 3 million confirmed cases of COVID-19 and more than 81,000 deaths due to the virus.