British Prime Minister Boris Johnson hailed a "significant milestone" on Sunday as data showed 15 million first doses of COVID-19 vaccinations had been delivered, fueling calls for the government to start relaxing far-reaching lockdown measures.
The vaccine program is seen as one of few successes in the government's handling of a pandemic that has left the country with a higher death toll and worse economic damage than its peers. The United Kingdom's total population is about 67 million.
After becoming the first in the world to approve a vaccine, the British government set an ambitious Feb. 15 target date to reach 15 million care home residents and staff, frontline health and care workers, all those aged 70 or over and the clinically extremely vulnerable.
Johnson said all those groups had been reached in England but did not speak for Scotland, Wales or Northern Ireland, and did not say the overall target had been met. In some areas those in lower priority groups have received jabs.
"Today we have reached a significant milestone," he said.
"No one is resting on their laurels... We've still got a long way to go and there will undoubtedly be bumps in the road, but after all we've achieved, I know we can go forward with great confidence."
He will set out further progress on Monday.
The vaccine program's success has led to calls from those opposed to prolonged lockdowns to begin easing restrictions that order citizens to stay at home, shut non-essential shops and close schools.
But foreign minister Dominic Raab said it was too soon yet to discuss when restrictions could be lifted.
"We share all of the ambition and the desire to get out of this lockdown, we want to do it responsibly and safely and therefore it's got to be based on the evidence," he told Times Radio.
Raab was responding to a letter from 63 lawmakers from the ruling Conservative Party that demanded that all lockdown measures be lifted by the end of April.
That is the government's next target date to have vaccinated the cohorts - an estimated 32 million people - that have so far accounted for 99% of all deaths.
"Once all nine priority groups have been protected by the end of April, there is no justification for any legislative restrictions to remain," the letter organized by the COVID Recovery Group said.
Johnson will set out on Feb. 22 the government's plans to end the lockdown. He has said he wants schools to reopen on March 8.