A coronavirus vaccine will be available in Britain from September, the chief executive of pharmaceutical company AstraZeneca has said.
Pascal Soriot told The Andrew Marr Show this morning that British people will get first access to the vaccine from autumn, despite concerns it will not be ready.
The pharmaceutical firm, which is working with Oxford University, had previously said it has secured the first agreements for at least 400 million doses of the vaccine.
But a leading member of the project told The Sunday Telegraph the lower transmission of Covid-19 in the community leaves the trial with only a 50 per cent chance of success.
Asked if people in Britain will be among the first to get the vaccine, Mr Soriot said: "Yes, we have actually received an order from the British Government to supply 100 million doses of vaccine, and those will go to the British people.
"And there's no doubt, starting in September, we will start delivering these doses of vaccine to the British Government for vaccination."
Mr Soriot said the possibility of the vaccine being rolled out in autumn depended on if an Oxford University trial worked before the transmission rate lowers further.
He added: "The vaccine has to work and that's one question, and the other question is, even if it works, we have to be able to demonstrate it.
"We have to run as fast as possible before the disease disappears so we can demonstrate that the vaccine is effective."
Oxford University's Jenner Institute and the Oxford Vaccine Group began development on a vaccine in January, using a virus taken from chimpanzees.
Following an initial phase of testing on 160 healthy volunteers between 18 and 55, the study is now set to progress to phases two and three, which involve increasing the testing to up to 10,260 people and expanding the age range of volunteers to include children and the elderly.
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-one 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."
Professor Adrian Hill, director of the Jenner Institute, said if the virus's spread is too low, not enough of the volunteers will catch it and the trial will be unable to definitively say if the vaccine works.
"It's a race against the virus disappearing, and against time," Professor Hill said.
"We said earlier in the year that there was an 80 per cent chance of developing an effective vaccine by September. But at the moment, there's a 50 per cent chance that we get no result at all.
"We're in the bizarre position of wanting Covid to stay, at least for a little while."
Business Secretary Alok Sharma has also suggested that if proved to work, half of the UK population could be given the vaccine by autumn.
Earlier this week, pharmaceutical giant AstraZeneca announced a $1.2bn deal with the US government to produce an additional 400 million doses.
The team is now looking to move its trials to coronavirus hotspots overseas, where the deadly bug is still spreading.
