The coronavirus vaccine candidate being developed by AstraZeneca and Oxford University induces a strong immune response and appears to be safe, according to preliminary trial results.
The early stage trial, which involved 1,077 people, has found that the vaccine causes few side effects and trains the immune system to produce antibodies and white blood cells capable of fighting the virus.
Professor Sarah Gilbert, of the University of Oxford, described the findings as promising but said there “is still much work to be done before we can confirm if our vaccine will help manage the Covid-19 pandemic”.
Prime minister Boris Johnson said the results were "very positive" as he congratulated the university and the team of scientists behind the vaccine.
“There are no guarantees, we’re not there yet & further trials will be necessary – but this is an important step in the right direction,” he said on Twitter.
In research published on Monday in the journal Lancet, scientists said that they found their experimental Covid-19 vaccine produced a dual immune response in people aged 18 to 55 – provoking a T-cell response within 14 days of vaccination and an antibody response after 28 days.
More trials will need to be conducted to establish how long these cells last for within the body. It is also unclear whether the vaccine can prevent people from falling ill or lessen the symptoms of Covid-19.
Researchers said the vaccine caused minor side effects more frequently than a control group, but some of these could be reduced by taking paracetamol, with no serious adverse events from the vaccine.
Larger trials evaluating the vaccine’s effectiveness, involving about 10,000 people in the UK, as well as participants in South Africa and Brazil, are now set to follow.
Another big trial is slated to start in the US soon, aiming to enrol about 30,000 people.
Explaining how the vaccine works, study lead author Professor Andrew Pollard, of the University of Oxford, said: “The new vaccine is a chimpanzee adenovirus viral vector (ChAdOx1) vaccine that expresses the SARS-CoV-2 spike protein.
“It uses a common cold virus (adenovirus) that infects chimpanzees, which has been weakened so that it can’t cause any disease in humans, and is genetically modified to code for the spike protein of the human SARS-CoV-2 virus.
“This means that when the adenovirus enters vaccinated people’s cells it also delivers the spike protein genetic code. This causes these people’s cells to produce the spike protein, and helps teach the immune system to recognise the SARS-CoV-2 virus.”
Oxford University has partnered with AstraZeneca to produce the vaccine globally, with the pharmaceutical giant already committed to making 2 billion doses.
The UK has ordered 100 million doses of the vaccine, while a number of other governments around the world, including the US, France and Germany, have entered into supply deals with the company should the candidate prove effective and gain regulatory approval.
AstraZeneca has said it will not seek to profit from the vaccine during the pandemic.
Health Secretary Matt Hancock said the update on the vaccine was “very encouraging news”.
He added: “We have already ordered 100 million doses of this vaccine, should it succeed.
“Congratulations to the scientists at UniofOxford & OxfordVacGroup and leadership of AstraZeneca.”
AstraZeneca’s vaccine is among the leading candidates currently being developed, with about a dozen others in the early stages of human testing or poised to start, mostly in China, the US and Europe.
Source : https://www.independent.co.uk/news/health/coronavirus-vaccine-oxford-university-study-trial-result-covid-19-safe-a9628491.html