The Covid-19 vaccine developed at Oxford University works perfectly and builds strong immunity to the virus, a study shows.
Great hopes rest on the vaccine, which is a global frontrunner and has been shown to safely trigger an immune response in volunteers given it in early trials.
But, unlike traditional vaccines which use a weakened virus, or small amounts of it, the innovative Oxford jab causes the body to make part of the virus itself.
Now researchers led by the University of Bristol have found this daring technology works for the coronavirus, just as it has for similar viruses in the past.
A study using cells in the laboratory found the vaccine effectively delivers the instructions for the Covid protein, which cells copy thousands of times to produce it in large amounts.
This means a person's immune system is then primed to recognise the disease and fight it off without them falling ill.
Dr David Matthews, from Bristol's School of Cellular and Molecular Medicine (CMM), who led the research, said: 'Until now, the technology hasn't been able to provide answers with such clarity, but we now know the vaccine is doing everything we expected and that is only good news in our fight against the illness.'
While the world waits for the results of trials on whether the Oxford vaccine actually works, the new findings are the next step forward.
In other coronavirus developments:
The virus vaccine developed at Oxford University works perfectly, a study shows (file photo)
The UK today announced another 21,242 positive tests and 189 deaths
Scientists found instructions from the vaccine were copied accurately by cells, making the protein correctly.
Sarah Gilbert, who leads the Oxford University vaccine trial, said: 'The study confirms that large amounts of the coronavirus spike protein are produced with great accuracy, and this goes a long way to explaining the success of the vaccine in inducing a strong immune response.'
The results were released as the Chief Scientific Adviser warned a widespread roll-out of a vaccine for Covid-19 is unlikely to take place before next year, even if a 'few doses' are available before Christmas.
Speaking at the Downing Street press conference, Sir Patrick Vallance said: 'Things are progressing well, there are vaccines that produce an immune response, they're in phase three clinical trials, we should be seeing some data read-outs over the course of this year, but I remain of the view that the possibility of wider-spread use of vaccines isn't going to be until spring or so next year, by the time we get enough doses and enough understanding of the outputs to use them.'
Sir Patrick said the aim would be for a vaccine to allow the 'release' of measures such as social distancing and mask-wearing.
He said: 'That's got to be an aim that we would all wish for, and that's why so many companies around the world are working on vaccines and why there has been such remarkable progress.'
The UK's chief scientific adviser also told peers this week that he thought Covid-19 would probably never disappear and that a vaccine won't stop it completely.
Sir Patrick also said he thought the virus will one day become like flu and cause outbreaks each year, and added that ministers and experts should stop 'over-promising' and be realistic about the prospects of a vaccine.
It is not likely that a jab will be completed before spring, Sir Patrick said, echoing his earlier warnings and those of his colleague Chris Whitty that the Covid-19 fight will be a long one.
In the same meeting, Sir Patrick said he still believes a flu pandemic is the biggest threat to the UK and that his office has set up a second system in case there is another crisis before the coronavirus epidemic comes to an end.
'I think it’s unlikely that we will end up with a truly sterilising vaccine – i.e. something that completely stops infection – and it’s likely that the disease will circulate and be endemic,' Sir Patrick said in a meeting of the Lords' National Security Strategy Committee.
'That’s my best assessment and I think that’s the view of many people on SAGE that that’s a likely outcome.
'Clearly, as management becomes better, as you get vaccination which will decrease the chance of infection and the severity of disease, or whatever the profile of the vaccines are, this then starts to look more like annual flu than anything else.
Sir Patrick Vallance appeared in front of the House of Lords's National Security Strategy Committee to caution that coronavirus might never completely disappeare
'That may be the direction we end up going in.'
An endemic virus is one that circulates constantly and never completely goes away. Examples of illnesses caused by endemic viruses include common colds, flu, HIV, chickenpox, cold sores and malaria.
While they all have treatments or ways to protect people from catching them, the viruses cannot be completely wiped out because they're already so widespread.
Flu vaccines, for example, are not perfect but reduce people's risk of getting seriously ill if they do catch the virus.
Flu is so hard to control because the virus mutates rapidly – sometimes once a year or more – which means protection from previous vaccines do not last for long.
Sir Patrick said this might be what happens with Covid-19, though added a ray of hope in that the coronavirus does not mutate anywhere near as fast. This raises the prospect that people may be able to develop long-term immunity to it.
It comes as scientists said that vaccine trials should not be stopped even in the event of death, following the death of a Brazilian doctor who was given a placebo dose in Oxford University's study.
Scientists found instructions from the vaccine were copied accurately by cells, making the protein correctly (file photo)
Dr Feitosa (pictured) had been treating Covid-19 patients since March in the emergency rooms and intensive care units at two hospitals in Rio de Janeiro
Dr João Pedro R. Feitosa, 28, is reported to have died from complications of Covid-19 on October 15. Brazilian newspaper Globo and news agency Bloomberg said he was in the control group and had received a placebo rather than the test vaccine, citing sources close to the trials.
Reacting to the news, Professor Gareth Williams, of the University of Bristol, told MailOnline: 'He's a very powerful message for a need for a vaccine, and to carry on with the trial to find what the answer is, and the need to educate people on how this matters.'
He said the 'exceptional event' still could have occurred had Dr Feitosa been given the experimental vaccine because no vaccine is 100 per cent effective. Professor Williams, who has written scientific papers on vaccines, says deaths should not stop trials going ahead.
Professor Ian Jones, a virologist at the University of Reading, said: 'What we have to remember is that in any large trial the normal processes of morbidity and mortality are still operating. The trial should continue to bring the vaccine to a decision point as soon as possible.'
Oxford University has since stated the phase three trial will continue, adding that an independent review had revealed no safety concerns.
Around 8,000 volunteers have been vaccinated so far in Brazil, one of the worst affected countries in the pandemic, and more than 20,000 worldwide, it said.
Results from the final trials are expected later this year, after early results showed a 'robust immune response' and no serious side-effects, making the Oxford vaccine one of the most promising hopes of bringing the pandemic to a standstill.
Race for a coronavirus vaccine: Nine candidates in final stage of clinical trials
As scientists race to develop a coronavirus vaccine to bring the world back to normal, MailOnline has taken a look at the prospective candidates.
Vaccine trials were halted on Wednesday but it may still be ready this year
The Oxford Vaccine
When will it be ready?: The end of 2020/ early 2021. Despite the trials being suspended on Wednesday, its developers and Number 10 remain confident that the vaccine could be ready for use either at the end of this year or early next year. They say a pause is common in trials, and that its development was also stopped in July after a suspected side-effect was detected.
How does it work?: The vaccine works by exposing participants to a weakened common cold adenovirus which has had proteins from the coronavirus SARS-CoV-2 attached to its surface. The idea is that the exposure allows the immune system to build an immune response, meaning they are protected if they are infected by the real virus.
Has the UK secured doses?: Yes, 100 million. The US has secured a further 300 million doses, along with several other countries. These will be rolled out in an equitable manner.
How much does it cost?: AstraZeneca, which is developing the vaccine with Oxford University, has said it will not profit from the it, but may earn extra royalties if the coronavirus becomes an endemic infection like flu. The US has spent $1.2 billion (£930 million) securing doses, meaning they are worth $4 (£3.10) each.
Biontech vaccine may be ready this year
When will it be ready?: At the end of this year, say researchers. The vaccine is being developed by a German company in partnership with American drugmaker Pfizer. It is recruiting 30,000 volunteers to its stage three trials.
How does it work?: This is an RNA vaccine, a type that has never been approved by regulators before. It will involve injecting a fragment of genetic material from coronavirus into participants. This will expose their immune systems to a weakened version of the virus and, hopefully, trigger a response which will protect them from the real virus.
Has the UK secured doses?: Yes, 30 million doses. The US has also ordered 100 million doses.
Price?: The US is paying $2 billion (£1.5 billion) for its doses, or about $20 (£15) a jab.
Moderna vaccine entered human trials
When will it be ready?: Very end of this year or next year. The vaccine has recruited 20,000 participants for its stage three trials. Providing no potential side effects are observed, it will then go through to a second test on more patients next month. This means it could be available by the end of 2020.
How does it work?: This is an RNA-based vaccine, similar to the one being developed by Biontech.
Has the UK secured doses?: No. Reports suggest the UK's task force has not managed to secure any doses of this vaccine.
How much does it cost?: The US has ordered 100 million doses at a price of $1.5 billion (£1.1 billion). This means one jab costs $32 (£25).
Sanofi and GlaxoSmithKline, UK and France
Sanofi vaccine won't be available this year
When will it be ready?: First half of 2021. The vaccine entered phase two clinical trials in September, involving 440 adults. It will reach phase three trials in December this year. There may be setbacks along the way, meaning the vaccine could take longer to develop.
How does it work?: Participants are injected with DNA coding for the antigens of the coronavirus and a chemical which makes it more potent. It is hoped this will trigger an immune response.
Has the UK secured doses?: Yes. Up to 60 million will be supplied should the vaccine be shown to work.
How much does it cost?: Unknown. This information has not been provided.
Sputnik V, Russia
Sputnik V is safe, according to Kremlin, but it has been criticised by scientists
When will it be ready?: 'Imminently'. The Russian medical research institute and Russian defence ministry have developed this vaccine. But it has faced serious criticism both inside and outside Russia because results from its human trials are yet to be published. It also hasn't cleared large human trials, with researchers only launching one involving 40,000 volunteers on 26 August. Scientists say the vaccine has been rushed without proper checks, and could pose a risk to those taking it. The Kremlin began appealing for volunteers for the vaccine this week after a first batch was produced, according to the TASS news agency.
How does it work?: The Russian vaccine works by carrying a piece of the coronavirus genetic code into a participant via another virus. It is hoped this will produce an immune response.
Has the UK secured doses?: No. Countries lining up to try the vaccine include Mexico, which has secured 32 million doses, and Kazakhstan, which is set to buy two million.
How much does it cost?: The price of the vaccine is yet to be revealed.
It is not clear when the Sinovac vaccine will be available
When will it be ready?: Unknown. The vaccine entered final-stage trials in Brazil in July, and then in Indonesia in August. Results show that while younger and middle-aged people produced antibodies, older people had a weaker immune response. The vaccine was given emergency approval for limited use in July, reports suggest, although it appears to still be subject to testing. It was previously reported as being second only to the Oxford vaccine, but its complete test results are yet to be published. It is one of four vaccine candidates in development in China.
How does it work?: It involves injecting patients with an inactivated form of the virus, prompting their immune systems to develop a response.
Has the UK secured doses?: Unknown. Reports suggest no doses have been secured.
How much does it cost?: China is yet to publish this information.