A coronavirus vaccine being developed at the University of Oxford is safe and induces an immune response to the disease, the first phase of human trials has revealed.
Doses of the vaccine, called AZD1222, were given to 1,077 healthy adults aged between 18 and 55 in five UK hospitals in April and May.
The results – published in the Lancet journal on Monday – show they induced strong antibody and T-cell immune responses for up to 56 days after they were given.
T-cells are crucial for maintaining protection against the virus for years.
Scientists found the response could be even greater after a second dose of the vaccine.
Compared to a control group, who were given a meningitis vaccine, the COVID-19 vaccine caused minor side effects more frequently, but those could be reduced by taking paracetamol. There were no serious adverse effects from the vaccine, the report said.
The UK government has made a deal with AstraZeneca and the University of Oxford to secure access to 100 million doses of the vaccine.
Professor Andrew Pollard, who is leading the study at the University of Oxford, said: “The immune system has two ways of finding and attacking pathogens – antibody and T-cell responses.
“This vaccine is intended to induce both, so it can attack the virus when it’s circulating in the body, as well as attacking infected cells.
“We hope this means the immune system will remember the virus, so that our vaccine will protect people for an extended period.
“However, we need more research before we can confirm the vaccine effectively protects against SARS-CoV-2 infection, and for how long any protection lasts.”
Professor Sarah Gilbert, co-author of the study, said: “There is still much work to be done before we can confirm if our vaccine will help manage the COVID-19 pandemic, but these early results hold promise.
“As well as continuing to test our vaccine in phase 3 trials, we need to learn more about the virus – for example, we still do not know how strong an immune response we need to provoke to effectively protect against SARS-CoV-2 infection.
“If our vaccine is effective, it is a promising option as these types of vaccine can be manufactured at large scale.”
Although these results are from phase one of the trials, phase two testing is already under way in the UK and phase three testing on volunteers in Brazil and South Africa is also taking place.
AstraZeneca’s vaccine is one of the leading candidates among several others around the world, including an injection being developed by China’s Sinovac Biotech, another from state-owned Chinese firm Sinopharm and one from US biotech firm Moderna.
The UK government has also secured early access to 90 million COVID-19 vaccine doses through partnerships with pharmaceutical companies, including 30 million of one being developed by BioNTech and Pfizer, and 60 million from Valneva which has a factory in Scotland.
‘The University of Oxford team is leading the global race for a COVID-19 vaccine’
By Thomas Moore, science correspondent
The first clinical trial results from the COVID-19 vaccine being developed by Oxford scientists suggest it triggers a strong double defence in the immune system.
Data from the phase 1 safety study reveals that volunteers produced a significant rise in both antibodies and killer T-cells that help to clear infection from the body.
The antibodies were able to kill the virus in lab tests, an early indication that the vaccine works.
Further research will be needed to confirm whether the immune response is sufficient to protect people from COVID-19.
The research also shows there were no serious side effects.
The scientists from Oxford University’s Jenner Institute have already progressed to phase 3 studies of the vaccine in collaboration with the pharmaceutical company AstraZeneca.
Several thousand volunteers in the UK, Brazil and South Africa are being given the vaccine to test its effectiveness.
The team is leading the global race to develop a vaccine.
The UK government has bought 100 million doses in advance of the results, with deliveries expected by the end of the year, if all goes well.