More than 20 million adults in the UK are now fully vaccinated against COVID-19 after receiving both jabs, according to government figures.
Some 391,246 people were given their second dose on Saturday, meaning a total of 20,103,658 (38.2% of all adults) have now had two shots.
Also on Saturday, 237,331 had their first jab, bringing the total number of people who have been given at least one dose to 36,573,354 (69.4% of the adult population).
The government has said it remains on track to offer a first dose to all adults in the UK by the end of July.
Health Secretary Matt Hancock said: "We have more great news about the vaccination rollout and are making extraordinary strides as 20 million people now have the fullest possible protection from this virus – huge thanks to the team for hitting this milestone.
"The latest real-world data has once again demonstrated how effective the vaccine is at providing life-saving protection, with two doses of the Pfizer vaccine providing 97% protection against mortality.
"Receiving a second dose is vital to ensure you have the ultimate protection from this deadly virus – I encourage everyone to book their jab as soon as they are offered it."
In Wales, it has been announced that more than two million people have now had a vaccine.
Almost three million doses in total have been administered in the nation in six months. This means 80% of all adults in Wales have received their first jab and one in three adults have had their second dose.
Meanwhile, the UK has reported another four coronavirus-related deaths and 1,926 new cases in the latest 24-hour period.
This compares with seven deaths and 2,027 cases announced on Saturday, while last Sunday two deaths and 1,770 cases were reported.
Since the pandemic began, a total of 127,679 people have died in the UK within 28 days of testing positive for COVID-19, and there have been 4,450,777 laboratory-confirmed cases.
The latest data was released as Mr Hancock said there is a "high degree of confidence" that vaccines protect against the Indian variant – but it can "spread like wildfire" among those who haven’t had a jab.
He said the Indian variant was "becoming the dominant strain in some parts of the country" such as Bolton and Blackburn.
Mr Hancock warned it can "spread even faster" than the Kent variant, which drove the UK’s deadly second wave of infections this winter, with a total of just over 1,300 cases found in the country so far.
He also claimed it was "appropriate" to push on with the major easing of restrictions in England on Monday despite concerns from scientists that it could be 50% more transmissible than the Kent strain.
And he urged those who are eligible for vaccination – but have not yet booked an appointment – to come forward to get their vaccine, adding he has not ruled out imposing local lockdown restrictions in places worst affected by the Indian variant.
Meanwhile, the director of public health at Blackburn with Darwen Council, Dominic Harrison, has tweeted he was "delighted" that "we now have a ‘green light’ to rapidly increase vaccinations".
He wrote: "An additional supply of over 1,000 per day (Pfizer) for next 2 weeks for both high variant spread areas and all residents over 18 (subject to eligibility)."