Coronavirus: Human trial of new vaccine begins in UK
Volunteers have begun being immunised with a new UK coronavirus vaccine.
About 300 people will have the vaccine over the coming weeks, as part of a trial led by Prof Robin Shattock and his colleagues, at Imperial College London.
Tests in animals suggest the vaccine is safe and triggers an effective immune response.
Experts at Oxford University have already started human trials.
The trials are among many across the world - there are around 120 vaccine programmes under way.
'I volunteered to help beat the virus'
Kathy, 39, who works in finance, is one of the first volunteers taking part in the Imperial trial.
She said she volunteered because she wanted to play a part in fighting the virus.
"I think it came from not really knowing what I could do to help, and this turned out to be something that I could do.
"And understanding that it's not likely that things will get back to normal until there is a vaccine, so wanting to be part of that progress as well."
After this first phase, another trial is being planned for October, involving 6,000 people.
The Imperial team hopes the vaccine could be distributed in the UK and overseas from early 2021.
Meanwhile the Duke of Cambridge met volunteers taking part in Oxford University's trial, at the city's Churchill Hospital.
Prince William told the volunteers: "It's the most incredibly exciting and very welcome project that you're all doing which is why it's fascinating."
A new approach
Many traditional vaccines are based on a weakened or modified form of virus, or parts of it, but the Imperial vaccine is based on a new approach, using synthetic strands of genetic code, called RNA, which mimic the virus.
Once injected into muscle, the RNA self-amplifies - generating copies of itself - and instructs the body's own cells to make copies of a spike protein found on the outside of the virus.
This should train the immune system to recognise and fight coronavirus without having to develop Covid-19.
Analysis by Fergus Walsh, Medical correspondent
Because only a tiny amount of genetic code is used in the Imperial vaccine, a little goes a very long way. The Imperial team says one litre of its synthetic material will be enough to produce two million doses.
Those doses have been produced in the US, but later this year manufacturing is switching to the UK, so that if and when it needs to be mass produced, it can be done here.
All clinical trials begin carefully and slowly to reduce safety risks. When the Oxford vaccine began in April, only two volunteers were immunised on the first day. Within a week, 100 were being jabbed every day.
The unique nature of the Imperial vaccine means that only one volunteer will be immunised on the first day, followed by three more every 48 hours. After a week or so, numbers will slowly ramp up.
Unlike the Oxford vaccine, which uses one dose, volunteers on the Imperial trial will get two shots, four weeks apart.
Prof Shattock and his team say there are no particular safety concerns with their jab - it's simply the newness of the approach which is making them proceed with caution.
There are more than 120 coronavirus vaccines in early development across the world. Most of these will never get beyond the laboratory. A further 13 are now in clinical trials: five in China, three in the United States, two in the UK, one in Australia, Germany and Russia.
All the vaccine teams are keen to stress that they are not in a race against each other, but against the virus. If there are to be enough doses to protect the world, several vaccine approaches will need to be successful.
Chief investigator for the study, Dr Katrina Pollock, added: "I wouldn't be working on this trial if I didn't feel cautiously optimistic that we will see a great immune response in our participants.
"The pre-clinical data looked very promising. We're getting a neutralising antibody response which is the immune response you would want to protect from infection. But there's still a long way to go to evaluate this vaccine."
The research has been funded by £41m from the UK government, as well as £5m of other donations.