AstraZeneca Pauses Coronavirus Vaccine Trial, Rollout Doubts Dent Shares

AstraZeneca has paused global trials of its experimental coronavirus vaccine after an unexplained illness in a participant, denting the British drugmaker’s shares on Wednesday as the move was seen as dimming prospects for an early rollout.

On Tuesday, AstraZeneca said it voluntarily paused trials, including late-stage ones, to allow an independent committee to review safety data, and it was working to expedite the review to minimise any potential impact on the trial timeline.

The vaccine, which AstraZeneca is developing with the University of Oxford, has been described by the World Health Organization (WHO) as probably the world’s leading candidate and the most advanced in terms of development.

“It is obviously a challenge to this particular vaccine trial,” Britain’s Health Secretary Matt Hancock told Sky News, adding: “It’s not actually the first time this has happened to the Oxford vaccine”.

The trial’s suspension triggered a 2% fall in AstraZeneca’s shares in London and a 12% drop in the stock price of its Indian unit, AstraZeneca Pharma India Ltd. AstraZeneca shares, which have the second biggest weighting in the FTSE 100 index, were down 0.3% at 0820 GMT.

It follows reports that the United States was aiming for a fast-track approval before the November presidential election.

Asked whether the pause would set back the vaccine development process, Britain’s Hancock said: “Not necessarily, it depends on what they find when they do the investigation.”

The BBC reported that a final decision on restarting the trial will be taken by the medical regulator the MHRA, which could take only days.

“This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials,” the AstraZeneca said in an emailed statement.

The nature of the illness was not disclosed, although the participant is expected to recover, according to Stat News, which first reported the suspension due to a “suspected serious adverse reaction”.

The U.S. Food and Drug Administration defines an adverse event as one in which evidence suggests a possible relationship to the drug being tested.