A great-grandmother who caught coronavirus five days after getting vaccinated against the disease has died.
Mary Green, 92, received her first dose at a care home in North Tyneside on New Year's Eve, giving her family hope she would not face an infection.
But less than a week later the dementia-sufferer tested positive for the virus.
Doctors said she couldn't be moved to hospital because she was too frail to undergo invasive treatment and would find the change of scene confusing, meaning she had to receive care at her home. She died 12 days later of suspected sepsis, which they said was likely triggered by the virus.
Scientists say it takes around two weeks for the vaccines to spark immunity, suggesting Mary's first dose came too late to protect her from the disease.
It comes as a top scientist today defended the decision to delay the second dose of the vaccine, arguing it could lead to better protection.
Professor Adam Finn, who helped make the priority list for jabs, said unpublished data suggests the immune response 'persists nicely' over the 12-week gap.
He added studies on other vaccines show immunity 'doesn't plateau and fall in (12 weeks)' after a first dose, but is likely to persist and 'even increase'.
Britain's regulators stretched the gap between doses to 12 weeks last month, saying it would 'protect the greatest number of people at risk in the shortest possible time'.
But the move has sparked concern as both the vaccines approved so far - by Oxford/AstraZeneca and Pfizer/BioNTech - rely on two doses to be most effective, with them ideally spaced three weeks apart.
Mary Green, 92, from North Tyneside, caught coronavirus five days after receiving her first dose of the vaccine. She later died of Sepsis, which doctors said was likely triggered by the infection. Vaccines take around two weeks to give protection.
Saturday alone saw 491,970 people get their first dose and 1,043 get their second, the highest daily figures recorded so far
Professor Adam Finn (left) says the 12-week gap between vaccine doses won't affect immunity. But Sam Monoghan (right), the head of the UK's largest charity care home, says he is worried it is leaving residents half-protected
DOCTORS UNION SAYS GAP BETWEEN DOSES SHOULD BE 'NO MORE THAN SIX WEEKS'
The British Medical Association (BMA) recommended cutting the waiting time to six weeks, warning in a letter that the strategy is 'difficult to justify' and the UK is 'internationally isolated'.
Dr Richard Vautrey, Chair of the BMA's GP Committee, told Sky News on Saturday that they are 'in dialogue' with Prof Whitty over the 12-week gap, saying 'we need to understand the data'.
Both the vaccines approved so far – one made by Pfizer and the other by Oxford University – rely on two doses to be most effective, with them ideally spaced three weeks apart.
But in a scramble to stop the devastating second wave of Covid-19, Britain has abandoned this rule and decided it will extend the gap to 12 weeks so it can give more people a single dose as soon as possible.
In a private letter to Professor Chris Whitty, the BMA indicated that second doses may not be guaranteed following a 12-week gap due to the 'unpredictability of supplies', reports the BBC.
Although agreeing that the jab should be 'rolled as quickly as possible', the association called for an urgent review of the policy that is 'proving evermore difficult to justify'.
A BMA spokesman told MailOnline: 'This letter to the Chief Medical Officer represents part of an ongoing dialogue about the best approach to the rollout of the vaccine and shares with him the growing concern from the medical profession regarding the delay of the second dose of the Pfizer/BioNTech vaccine as the UK's strategy has become increasingly isolated from many other countries.
Mary's heartbroken son Chris, 52, said the family had a visit to see Mary at Charlton Court care home cancelled on January 2 due to lockdown, reports ChronicleLive.
'She was a casualty of what we're going through at the moment with Covid,' he told the newspaper.
'The care she needed in her final days wasn't in care home setting, it was in a hospital setting, and she couldn't have that.'
A family member - who asked not to be named - said they thought Mary had received the vaccine either just before or just after she was infected.
'You do wonder if they've let their guard down once they've had the vaccine,' they said.
'We haven't been inside the home since March, we've only been able to see her from outside under a gazebo behind a screen.'
Professor Finn, who is a member of the Joint Committee on Vaccinations and Immunisations (JCVI), said today data suggests the delayed second dose could give better protection.
'The data that I've seen - which has not yet been published - suggests certainly that (immunity) persists nicely through (the 12 weeks),' he told BBC Radio 4's Today programme.
'If anything it slightly rises and certainly there is no sign of any significant fall.
'But more importantly, as I say, is that the delayed second dose is going to give us better protection on into the year.'
The Bristol University professor added: 'What we know from other vaccines and from the human immune responses is that they don't plateau and fall in that time period.
'It's likely that there will be persistent and even increasing protection over that time and perhaps most important of all we expect to see much better protection after the second dose even if it's delayed.
'We know that for the Oxford vaccine and we know that for many other vaccines.'
When quizzed on the BMA's warning against the lengthy gap between doses, he accused them of failing to 'understand the issues'.
'The fact is that other countries are looking at what the UK is doing with enormous interest,' he said.
'This may well turn out to be another example of a long tradtions in us being innovative, creative in our resources, and producing a much better way of using the vaccines.'
Amid mounting concern over the decision to delay the second dose Sam Monaghan, the chief executive of care home provider MHA care, said he felt residents were being 'left more vulnerable' because of the time between the first and second doses.
'(Our concern is) whether the lengthening of the gap between the two doses for such a highly vulnerable group of our society, when that seems to be against the guidance from the World Health Organization and the manufacturer’s own guidance, what the impact of that is.
The Prime Minister Boris Johnson pictured visiting a vaccination centre at The Hive, North London, today. The Government is aiming to get 15million of the most vulnerable their first doses by mid-February
'I suppose, inevitably, it leaves you feeling that our homes and our older people are left more vulnerable because there’s a longer time that they’re unprotected from the first dose.'
He added: 'It's leaving our residents with only 50 per cent or 60 per cent of the protection that they would have, and when we know that it would be around the 90-95 per cent mark if they’d had both doses.'
The British Medical Association (BMA), the doctors trade union, called for the gap to be cut to no more than 6 weeks this weekend, saying the delay between doses could reduce the effectiveness of the vaccine.
Dr Chaand Nagpaul, its chair of council, said called for the UK to follow 'best practice' and reduce the waiting time to six weeks.
'Most nations in the world are facing challenges similar to the UK in having limited vaccine supply and also wanting to protect their population maximally. No other nation has adopted the UK’s approach,' Dr Nagpaul told BBC Breakfast on Saturday.
'Obviously the protection will not vanish after six weeks but what we do not know is what level of protection will be offered. We should not be extrapolating data where we don’t have it.
'I do understand the trade-off and the rationale but if that was the right thing to do then we would see other nations following suit.
He added: 'The concern we have if the vaccine’s efficacy is reduced then of course the risk is that we will see those who are exposed maximally to the virus may get infected.
'The other worry is that members of the population, those who are at highest risk, may not be protected.'