More than 600 people in England who had received both Covid shots died after contracting the virus during the first half of this year, newly released statistics have shown.
The number includes people who had been infected before they received their second dose.
The ONS said there were 256 "breakthrough deaths", a term used for someone testing positive for the first time 14 days after their second vaccination dose.
Men accounted for 61.1 per cent of such deaths.
Over three quarters of these deaths (76.6 per cent) occurred in those who were clinically extremely vulnerable.
More than 43 million people have been fully vaccinated in the UK.
The figures show the risk of death involving Covid-19 is consistently lower for people who receive two vaccinations compared with one or no vaccination.
From January 2 to July 2, there were 51,281 Covid-related deaths registered in England, according to the Office for National Statistics (ONS).
Of the fatalities, 640 (1.2 per cent) had been given both shots.
A total of 458 people passed away after the 21-day mark following their second shot while 182 people died within three weeks of being double vaccinated.
The 640 deaths accounted for 1.2 per cent of all deaths involving coronavirus that occurred in England in the first seven months of this year.
The number of people who died between January 2 and July 2 who had not received any Covid vaccine was 38,964.
Julie Stanborough, deputy director of health and life events at the ONS, said: “Our new analysis shows that, sadly, there have been deaths of people involving Covid-19 despite them being fully vaccinated.
“However, we’ve also found that the risk of a death involving Covid-19 is much lower among people who are fully vaccinated than those who are unvaccinated or have only received one dose.
“This shows the effectiveness of the vaccines in giving a high degree of protection against severe illness and death.”
The release of the data comes after a rise in infections among people who have received both doses cast doubt on the efficacy of Covid vaccines.
And the figures give weight to warnings from scientists that the virus remains a threat to people even after they have been fully vaccinated, as no jab is 100 per cent effective.
Scientific experts have said regardless of which vaccine is administered, it takes around two weeks after the second dose for a person to build up immunity against the virus.
Natalie Dean, a biostatistics professor at Emory University, recently warned about the spread of the delta variant of Covid-19, saying it made it “a lot harder” to stop transmission.
As of September 11, 80.9 per cent of the UK population had been fully vaccinated while 89.1 per cent had received their first dose.
On Sunday the UK recorded 56 new Covid deaths within 28 days of a positive test and 29,173 infections.
The release of the ONS data comes as Britain’s Prime Minister Boris Johnson prepares to unveil his Winter Plan to tackle Covid.
Media reports suggest he is hoping to rely on vaccines and booster shots for some adults deemed vulnerable in a bid to stave off having to impose another lockdown.
The release of the ONS data comes as Britain’s Prime Minister Boris Johnson prepares to unveil his Winter Plan to tackle Covid.
Media reports suggest he is hoping to rely on vaccines and booster shots for some adults deemed vulnerable in a bid to stave off having to impose another lockdown.
The package also includes proposals to reintroduce social distancing requirements and the mandatory face mask rule for indoor public spaces if the pandemic worsens.
And vaccine passports could be rolled out if the UK’s National Health Service (NHS) is one the cusp of becoming overwhelmed by Covid patients.
A senior government source told The Telegraph that Mr Johnson will tell Britons “we need to learn to live with Covid” when he sets out his plan tomorrow.
