Clinical trials were put on hold for the new drug. In response shares in AstraZeneca, the company making the vaccine, collapsed.
The suspension took place after at least one of the people taking part in the trial became ill.
In a statement AstraZeneca said: “As part of the ongoing randomised, controlled global trials of the Oxford coronavirus vaccine, our standard review process triggered a pause to vaccination to allow review of safety date.
“This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials.
“In large trials illnesses will happen by chance but must be independently reviewed to check this carefully.
“We are working to expedite the review of the single event to minimize any potential impact on the trial timeline.
“We are committed to the safety of our participants and the highest standards conducted in our trials.”
More to follow…