LONDON: Pharma giant AstraZeneca and Oxford University on Saturday said they had resumed a Covid-19 vaccine trial after getting the all-clear from British regulators, following a pause caused by a UK volunteer falling ill.

"Clinical trials for the AstraZeneca Oxford coronavirus vaccine, AZD1222, have resumed in the UK following confirmation by the Medicines Health Regulatory Authority (MHRA) that it was safe to do so," the company said in a statement.

AstraZeneca announced on Wednesday it had "voluntarily paused" its trial of the vaccine developed alongside Oxford University after the volunteer developed an unexplained illness.

An independent committee was drafted in to review safety, in what the company and the World Health Organization described as a routine step. The committee "has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume", AstraZeneca said.

Oxford University confirmed the resumption and said: "In large trials such as this, it is expected that some participants will become unwell and every case must be carefully evaluated to ensure careful assessment of safety."

After the pause, AstraZeneca had said it remained hopeful that the vaccine could still be available "by the end of this year, early next year".

But pharma companies including AstraZeneca and scientists have expressed concern about political pressure to rush a vaccine out, not least from US President Donald Trump.