The Medicines and Healthcare products Regulatory Agency (MHRA) has ruled that the vaccine is safe and should be administered in two standard doses up to 12 weeks apart, rather than four, with the government aiming to use the first wave of supplies on as many people as possible.
According to trial data shared with the MHRA, the three-month interval helps to induce an immune response that is 80 per cent effective in preventing the disease.
The half-dose, full-dose regime, which appeared to be 90 per cent efficacious, was not endorsed by the MHRA, which said the “results were not borne out by the full analysis”.
Matt Hancock, the health secretary, said the approval was “fantastic news” and a “moment to celebrate”, while Boris Johnson called it “a triumph for British science”.
A Department of Health and Social Care (DHSC) spokesperson said: “The government has today accepted the recommendation from the Medicines and Healthcare products Regulatory Agency to authorise Oxford University/AstraZeneca’s Covid-19 vaccine for use.
“This follows rigorous clinical trials and a thorough analysis of the data by experts at the MHRA, which has concluded that the vaccine has met its strict standards of safety, quality and effectiveness.”
Distribution of the vaccine is set to begin next Monday, with the government optimistic that more than two million vulnerable people could receive their first dose by mid-January.
It is hoped that all at-risk groups will have been vaccinated using the Oxford or BioNTech-Pfizer candidate by the end of April, helping to ease the strain on the NHS amid a deluge of hospitalisations driven by the new coronavirus variant.
A total of 100 million doses have been pre-ordered by the UK – enough to vaccinate 50 million Britons.
The government missed its target of producing 30 million doses by September, the UK’s vaccine taskforce chief admitted last month. At the time, Kate Bingham said she expected there to be 4 million doses available by the end of the year – yet Mr Hancock said on Wednesday this figure stood at 530,000.
Pascal Soriot, chief executive of AstraZeneca, said the manufacturer would be able to provide “one million doses and beyond” per week.
The Oxford vaccine has long been seen by Whitehall as a critical tool in ending the acute phase of the Covid crisis due to its low cost and ease of storage.
Compared to the BioNTech-Pfizer vaccine, which must be kept at -70C and can be moved only four times within a cold chain before being used, the Oxford candidate can be stored at fridge temperature for up to six months and repeatedly relocated.
This will allow health authorities to quickly transport thousands of doses to hospitals, mass vaccination sites, GPs and even pharmacies across the UK.
Professor Martin Marshall, chair of the Royal College of General Practitioners, said the Oxford-AstraZeneca jab will make it easier for family doctors to vaccinate more people, more quickly.
“It is the glimmer of light at the end of the tunnel that we desperately need to get us through this difficult winter and ultimately overcome the virus,” he said.
The vaccine is expected to accelerate the lifting of restrictions that were implemented earlier this month in response to the UK’s coronavirus variant – but only if the “rollout goes according to plan”, Cabinet Office minister Michael Gove said on Monday.
Across the four nations, work has been underway to transform football stadiums, conference centres and racecourses into mass vaccination centres that will eventually allow up to 2 million people a week to receive the jab.
People receiving the Oxford vaccine or the Pfizer-BioNTech candidate, which was approved earlier this month, will be injected with their first dose followed by a booster jab up to 12 weeks later, the Joint Committee on Vaccination and Immunisation (JCVI) said on Wednesday.
The aim is to give as many people as possible a first dose of a Covid-19 vaccine, rather than reserving initial supplies for a second jab.
The DHSC said: “Having studied evidence on both the Pfizer-BioNTech and Oxford-AstraZeneca vaccines, the JCVI has advised the priority should be to give as many people in at-risk groups their first dose, rather than providing the required two doses in as short a time as possible.
“Everyone will still receive their second dose and this will be within 12 weeks of their first. The second dose completes the course and is important for longer term protection.”
Professor Wei Shen Lim, chair of the JCVI, said this “will allow the greatest number of people to receive the vaccine in the shortest possible time – and that will protect the greatest number of lives”.
In a joint statement, the chief medical officers of the four nations said they agreed with the JCVI that first doses should be prioritised. Former prime minister Tony Blair similarly advocated such a policy, writing last week in The Independent that the UK’s vaccination plan needed to be “altered and radically accelerated” in response to the new variant.
Although the Oxford vaccine has been heralded as a game-changer in the fight against Covid-19, its journey to authorisation has been mired by controversy and apparent irregularities in the trial data.
It was revealed last month that the half dose-full dose regime delivered an efficacy rate of 90 per cent.
But separate data showed that the vaccine was only 62 per cent effective when administered as two full doses over a four-week period. Scientists have yet to fully explain the discrepancy in results between the two dosing regimes.
Dr June Raine, chief executive of the MHRA, said “extremely careful” consideration was paid to the different dosing regimes implemented during the large-scale trials and the points at which the second shots were administered.
In some subgroups of the trial, volunteers were given their follow-up jab 26 weeks after the first dose, the regulatory body said.
However, the MHRA settled upon the standard two-full dose programme over a three-month time frame as trial data for this regime was the “most robust”.
Questions have also been raised of whether the vaccine was tested on enough people over the age of 55. Only 12 per cent of study participants were from this age group and they were enrolled later on in the trial.
Professor Sir Munir Pirmohamed, of the Commission on Human Medicines, said there was a “small amount of data available” which pointed to the effectiveness of the vaccine in the elderly.
"Older people have been recruited and more data and older people will be coming online in early 2021, not only from the UK trial but also from the trial in Brazil, but also the trial being undertaken in the United States,” he said.
Dr Raine added that pregnant women would be able to receive the Oxford jab, but only after a risk assessment, and said that “people who are advised not to have either of the vaccines are those with allergies who've had reactions to any of the ingredients”.
It also remains unclear whether the vaccine will be able to halt the transmission of Covid-19 – though there are some indications of this from the early data that has been collected.
A total of 6,638 volunteers in the UK trial were asked to complete weekly swab tests during the phase three study to identify any asymptomatic infections.
From this group, 69 such cases were detected, with the majority coming in the control group who did not receive the vaccine. This enabled researchers to determine that the vaccine is 27 per cent effective in preventing asymptomatic transmission.
Sir Munir said, at this stage, the data “was not mature enough”, meaning the MHRA was unable to make any recommendations regarding transmission.
AstraZeneca has committed to manufacturing 3 billion doses of the vaccine throughout 2021. The British-based pharmaceutical has pledged to sell it at cost to developing nations in perpetuity, while its ease of storage means it will be readily accessibly for the world’s poorest and most vulnerable populations.
Professor Andrew Pollard, director of the Oxford Vaccine Group, who led the clinical trial, said the approval was “a landmark moment”.
But he said the impact of vaccines is “about getting them into people’s arms, stopping the virus from causing severe disease and hospitalisation, which we know that all of the vaccines can do very efficiently”.
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