Britain may not be free of coronavirus restrictions until next winter unless the NHS hits its ambitious target of vaccinating 2million people every week, it is feared.
Ramping up the inoculation drive to reach the target means it would still take until April for everyone over the age of 50, adults with serious illnesses, and millions of NHS and social care workers to get their first dose.
But it would take another 15 weeks for the same Britons to get the second dose they need to offer them as much protection against the disease as possible, meaning the deadline won't be hit until August at the earliest.
Number 10 could, however, ease restrictions before then, if they believe they have protected enough of the population to prevent hospitals being overwhelmed.
But there are still huge questions about whether the NHS will be able to hit 2million jabs a week target, which scientists say Britain needs to get to 'very quickly' to have any hope of a normal summer.Insurance Loans Mortgage Attorney Credit Lawyer
AstraZeneca bosses have pledged to deliver the milestone figure of doses a week by mid-January. And the NHS has promised it will be able to dish them out as quickly as it gets them.
But there already appears to be cracks forming in the supply chain. Only 530,000 doses of the Oxford coronavirus vaccine will be available for vulnerable people this week, despite officials promising at least 4million just weeks ago.
Boris Johnson says the roll-out was being stalled because officials were waiting for batches of the jab to be approved by the regulator, while Matt Hancock has blamed AstraZeneca for being too slow to manufacture the doses.
The PM is due to address the country tonight at 8pm, when he is expected to put the country into a third national lockdown amid spiking infections and admissions, with vaccines now the only way out of the endless cycle of lockdowns.
Brian Pinker, 82, became the first person in the world to receive the Oxford University vaccine today
The UK's vaccination programme has only managed to inoculate 1million people in the four weeks it has been operational.
But officials have promised the scheme will drastically speed up when clinics start using the game-changing Oxford University/AstraZeneca jab, which was rolled-out for the first time today.
Coronavirus vaccines could be ineffective against the highly-infectious South African mutation, a scientist who helped develop the Oxford jab has warned.Insurance Loans Mortgage Attorney Credit Lawyer
Sir John Bell, regius professor of medicine at Oxford University, said the African strain is more concerning than the Kent one.
Vaccines are believed to be effective against the highly-infectious UK variant VUI-202012/01 currently causing a massive spike in cases across the country.
But he said the South African variant 501.V2 - detected in two locations in Britain - has 'really pretty substantial changes in the structure of the protein' meaning vaccines could fail to work.
The Covid vaccine protects against the disease by teaching the immune system how to fight off the pathogen.
It creates antibodies - disease-fighting proteins made and stored to fight off invaders in the future by latching onto their spike proteins.
But if they are unable to recognise proteins because they have mutated, it means the body may struggle to attack a virus the second time and lead to a second infection.
However, experts told MailOnline today there was no publicly-available data to suggest the strain possesses the ability to escape the