REASEARCHERS have begun recruiting volunteers for the next two phases in clinical trials they hope could bring a coronavirus vaccine this year.

Work began in January on the vaccine, which uses a virus taken from chimpanzees and has been developed by the University of Oxford's Jenner Institute and the OxfordVaccine Group.

The first phase of trialling involved 160 healthy volunteers between 18 and 55.

Now scientists want to recruit up to 10,260 people across the country for phases II and III, which involve vastly increasing the number of volunteers and expanding the age range to include older adults and children.

Professor Andrew Pollard, head of the Oxford Vaccine Group, said: "The clinical studies are progressing very well and we are now initiating studies to evaluate how well the vaccine induces immune responses in older adults, and to test whether it can provide protection in the wider population.

Sarah Gilbert, professor of vaccinology at the Jenner Institute, said: "We have had a lot of interest already from people over the age of 55 years who were not eligible to take part in the phase I study, and we will now be able to include older age groups to continue the vaccine assessment.

"We will also be including more study sites, in different parts of the country."

Read more: meet the family who have been taking part since the start

Saul Faust, professor of paediatric immunology and infectious diseases at the University of Southampton, which is also working on the trials, said: "We would now very much like to invite people from the Southampton area whose work brings them into possible contact with Covid patients or who are healthy and in the older age groups to take part in the next stage of trials of this Oxford Covid vaccine.

"This is one of only four vaccine trials underway worldwide and could pave the way for a vaccine to be delivered later this year."

Initially, researchers are aiming to recruit up to 620 new volunteers in three categories:

Researchers will assess the immune response to the vaccine in people of different ages, to determine how well the immune system responds in older people or children.

Adult participants in the phase II and phase III groups will be randomised to receive one or two doses of either a vaccine known as ChAdOx1 nCoV-19, or a licensed vaccine (MenACWY) that will be used as a 'control' for comparison.

ChAdOx1 nCoV-19 is made from a weakened version of a common cold virus from chimpanzees that has been genetically changed to make it impossible for it to grow in humans.

This has been combined with genes that make proteins from the Covid-19 virus (SARS-CoV-2) which play a key role in the infection pathway of the SARS-CoV-2 virus.

Production of the vaccine has already been scaled up ahead of the trial to prepare as early as possible for potential future deployment.

AstraZeneca said this week it had the capacity to manufacture one billion doses of the University of Oxford's potential Covid-19 vaccine and could begin supply in September.

The pharmaceutical firm said it has secured the first agreements for at least 400 million doses of the vaccine.