THE Covid-19 vaccine being developed at the University of Oxford is safe and induces an immune reaction, preliminary results of the study suggest.
Researchers say their tests have revealed that the jab could provide double protection against the virus.
The early-stage trial found that the vaccine is safe and causes few side effects.
It also induces strong immune responses in both parts of the immune system — provoking a T cell response within 14 days of vaccination and an antibody response within 28 days.
Compared with the control group of those given a meningitis vaccine, the Covid-19 vaccine caused minor side effects more frequently, according to the study.
But some of these could be reduced by taking paracetamol, the researchers said, adding that there were no serious adverse events from the vaccine.
Co-author Professor Sarah Gilbert, of the University of Oxford, 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-three 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.
‘A successful vaccine against Sars-CoV-2 could be used to prevent infection, disease and death in the whole population, with high-risk populations such as hospital workers and older adults prioritised to receive vaccination.’
The current results focus on the immune response measured in the laboratory, and further testing is needed to confirm whether the vaccine effectively protects against infection.
An ideal vaccine against Sars-CoV-2 should be effective after one or two vaccinations and work in target populations including older adults and those with other health conditions, researchers say.
They add that it should confer protection for a minimum of six months, and reduce onward transmission of the virus to contacts.
However, the experts warn that the current trial, published in The Lancet, is too preliminary to confirm whether the new vaccine meets these requirements.
Phase-two — in the UK only — and phase-three trials to confirm whether it effectively protects against the virus are taking place in the UK, Brazil and South Africa.
The trial included 1,077 healthy adults aged 18-55 years with no history of Covid-19, and took place in five UK hospitals between April 23 and May 21.
The data included in the paper covered the first 56 days of the trial and is ongoing.
The authors note a number of limitations to their study, saying more research is needed to confirm their findings in different groups of people — including older age groups, those with other health conditions, and in ethnically and geographically diverse populations.
In the current trial, 91 per cent of participants were white and the average age of participants was 35.
As well as the 100million doses of the vaccine being developed by Oxford University with AstraZeneca, the government has signed deals for 90million doses of other promising Covid-19 vaccines, with more in the pipeline.
The latest deal is for vaccines being developed by an alliance between the pharmaceutical giants BioNtech and Pfizer as well as the firm Valneva.
Kate Bingham, chairwoman of the UK Vaccine Taskforce, said she was hopeful of a vaccine by the end of the year.
She told BBC Radio 4’s Today programme that ‘optimistically we will be vaccinating by the end of the year’ but added that she would not ‘go to the bank on it yet’.
She also said the goal of the taskforce was ‘to find vaccines for the UK, but also to ensure that any successful vaccine is distributed across the globe, so that anybody who is at risk of infection is vaccinated’.
She told Sky News: ‘We’re not pursuing a strategy of vaccine nationalism.
‘We are recognising that this is a global pandemic and we need to ensure that the globe — and all those who need it — are vaccinated.’
The government aims to build a portfolio of potential vaccines alongside effective treatments for coronavirus.
The latest announcement is for 30million doses of a vaccine from BioNTech/Pfizer, 60million doses from Valneva, with an option to acquire a further 40million if needed.
If the BioNTech/Pfizer vaccine is shown to work, regulatory review could be sought as early as October, with up to 100million doses potentially manufactured by the end of the year.
The government has also signed a deal with AstraZeneca for one million doses in principle of a treatment containing Covid-19 neutralising antibodies.
This could protect those who cannot receive vaccines, such as people with cancer or whose immune system is severely compromised.
A new NHS Covid-19 vaccine research registry has also been established with the aim of recruiting 500,000 volunteers by October to test new vaccines and treatments.
Meanwhile, trials of an inhaled coronavirus treatment found that hospital patients who took the drug had a 79 per cent lower risk of developing severe disease.
According to early results of the study, patients who received the drug, known as SNG001, were more than twice as likely to recover from Covid-19 as those who received a placebo.
The treatment has been developed by the pharmaceutical company Synairgen.
■ The vaccine registry can be found at: nhs.uk/conditions/coronavirus-covid-19/research/coronavirus-vaccine-research/