OXFORD'S efforts to develop a vaccine against the coronavirus have seen 'very encouraging' results from the first human trials.

The findings, published in medical journal the Lancet today, show the vaccine induces an immune reaction, producing both antibody and white blood cells (T-cells) which can fight Covid-19.

It also found the vaccine was safe to progress to larger-scale testing and two doses may be more effective.

Professor Andrew Pollard, chief investigator of the Oxford University study, said the results were 'very encouraging' saying: "What they show is a really important milestone on the path to development of the vaccine."

He added the findings revealed the vaccine was 'very well tolerated' by the 1,077 volunteers who took part in the first phase and scientists were seeing good immune responses both in antibodies and T-cells.

Also read: Major upgrade at JR to affect surgeries for three months

He said: "We are now moving rapidly forwards to try to evaluate whether the vaccine actually protects the population by conducting large-scale trials."

The vaccine, called ChAdOx1 nCoV-19, is made from a genetically-engineered version of the virus that causes the common cold in chimpanzees.

It has been weakened so it cannot cause infections in people and genetic material, called spike proteins, have been added so it resembles Covid-19 and can therefore train the immune system to fight it.

This is done in two ways which work together.

Oxford Mail:

Prince William visiting the Oxford vaccine team last month

Professor Sarah Gilbert, leading the Oxford team of scientists, explained: "Antibodies are in fluids in the body and they can encounter viruses when they first come into the body and the antibodies can bind onto the outside of the virus to stop them infecting cells.

"The T-cells do a different thing, they don't recognise viruses but what they recognise is cells that have been infected with viruses. The virus is taking over that cell and turning it into a factory to make lots more viruses."

She said they could then destroy these cells and prevent an infection spreading.

Also read: Oxford vaccine timeline - how we got this far

The first phase of the clinical testing in humans recruited volunteers aged between 18 and 55 years old across multiple sites, including in Oxford, with half of participants randomly allocated to receive the vaccine and half a placebo vaccine against meningitis.

A small additional group of 10 were give two doses of the vaccine four weeks apart.

Oxford Mail:

Katie Viney and her husband Tony and daughter Rhiannon all took part in the coronavirus vaccine trial. Picture: Ed Nix

The Lancet report showed levels of T-cells peaked 14 days after vaccination and antibody levels peaked after 28 days.

While there were no serious side-effects, many of the participants who received the vaccine reported mild flu-like symptoms, such as a headache, chills and fatigue, in the first days after being injected.

Professor Gilbert said there was 'still a long way to go' explaining: "The difficulty that we have, and that all vaccine developers have, in trying to make a vaccine against this particular virus is we don't know how strong that immune response needs to be.

"So we can't say just by looking at immune response whether this is going to protect people or not."

She said large-scale testing and waiting for people to be infected as part of that trial was the only way to find out.

Oxford University's Jenner Institute and Oxford Vaccine Group began development of a vaccine in January and last month pharmaceutical giant AstraZeneca signed a deal to help manufacture 300 million globally accessible doses when it is ready.

This has now increased to contracts for two billion doses, with the UK ordering 100 million of the vaccine.

Also read: Best and worst GP practices revealed - as voted by patients

On time scales, Professor Adrian Hill, head of the Jenner Institute, said it was 'possible' a vaccine could be approved for use by the end of the year but it relied on enough coronavirus cases in the 50,000 people who will globally by involved in trialling the vaccine.

Speaking to this paper, Professor Teresa Lambe, who is among the Oxford scientists working on the vaccine, said the entire team were 'super excited' to finally share their findings with the world.

Though she has been involved with vaccine development for more than a decade, she said the 'scale and pace' of the coronavirus vaccine was unlike anything she had experienced before.

Oxford Mail:

Oxford University's Jenner Institute

She said: "I'd say we crammed eight years into four months. That was possible because we were doing everything in tandem, so we were lining up manufacturing at the same time as working on creating the vaccine."

Professor Lambe added the team were working 12-14 hours a day, seven days a week, saying: "It's not external pressure but I do think you put pressure on yourself."

She also said while the study was focusing on large-scale testing in countries such as the US and Brazil where people are more likely to encounter coronavirus, there was still lots to be done in Oxford.

The focus for researchers includes how the vaccine works in older people as well as dosing levels.