The UK has recorded 23,510 new COVID-19 cases and 146 more coronavirus-related deaths in the latest 24-hour period, according to government data.
The figures compare with 25,161 infections and 37 fatalities reported on Monday, while last Tuesday 29,703 cases and 62 deaths were announced.
The number deaths reported today is the highest daily total since 175 were recorded on 12 March.
Since the pandemic began, a total of 130,503 people have died in the UK within 28 days of testing positive for coronavirus, and there have been 6,117,540 confirmed infections.
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Meanwhile, 32,250 people had their first dose of the COVID-19 vaccine on Sunday taking the total to 47,091,889.
And 137,028 had their second jab, meaning 39,688,566 are now fully inoculated.
On Tuesday, the Department of Health and Social Care (DHSC) announced 75% of adults in the UK have now received both doses and 89% of people have had one jab.
Prime Minister Boris Johnson described the milestone as “a huge national achievement which we should all be proud of”.
“Our incredible vaccine rollout has now provided vital protection against the virus to three-quarters of all UK adults. This is a huge national achievement, which we should all be proud of,” the PM said in a statement.
According to the latest data from Public Health England and Cambridge University about 60,000 deaths, 22 million infections and 66,900 hospitalisations have been prevented by the vaccines.
It is believed two jabs provide over 90% protection against hospitalisation from the Delta variant, which is the dominant strain in the UK at present.
Earlier on Tuesday, Professor Andrew Pollard, director of the Oxford Vaccine Group, has claimed herd immunity is “not a possibility” with the current Delta variant.
He described the idea as “mythical” and warned that a vaccine programme should not be built around the idea of achieving it.
Speaking during a session of the All-Party Group on COVID-19, he said: “We know very clearly with coronavirus that this current variant, the Delta variant, will still infect people who have been vaccinated and that does mean that anyone who’s still unvaccinated, at some point, will meet the virus.”