A vaccine to guard against Covid-19 under development in the UK has shown hopeful signs of providing ‘double protection’ against the virus. Reports on Thursday suggested that early trials on 1,100 people by a team at Oxford University had triggered a response in the half of the group given the treatment. Blood samples taken from the volunteers suggested the vaccine stimulated the body to produce antibodies to tackle the virus and a type of white blood cells, known as T-cells, that help the body destroy infections. The T-cells are seen as significant after studies on people who have had the coronavirus suggested that antibodies developed by the body have only a limited lifespan, suggesting the disease could be caught again. The findings from the Oxford study follow positive news from the United States, where biotech company Moderna said it would start the final stage of human trials this month after the success of initial tests on a smaller group of volunteers. Pfizer and BioNTech also said that two of four possible vaccines had received "fast-track" designation from US officials. The teams are among the leading research groups amid dozens of attempts to find a vaccine around the world. The findings of the initial study at Oxford are expected to be published in the medical journal <em>The Lancet</em> on Monday after final editing and preparation, the university said. Despite the positive early signs, researchers said it was too early to say if the findings would translate to a vaccine that could stop people from dying. David Carpenter, the chairman of the ethics committee that approved the trial, told <em>The Telegraph</em> newspaper that the research was on track. “Things might go wrong but the reality is that by working with a big pharma company, that vaccine could be fairly widely available around September and that is the sort of target they are working on.” The Oxford team announced in May that it was recruiting more than 10,000 people for a second phase of trials. It is also working on testing in other countries to ensure large-scale sampling of enough people infected with the virus as the number of cases falls in the UK. Oxford has partnered with the drug maker AstraZeneca to make millions of doses of the drug that it has pledged to make available at low cost. The drugs company’s shares rose 5.2 per cent on Wednesday but fell back 0.7 per cent in early trading on Thursday. It has not commented on the reports surrounding the success of the trial.