AstraZeneca halts human trials of COVID vaccine after volunteer takes ill

The company says the action is routine and is taken to ensure the integrity of the trials

So far 4.5 crore people have been inoculated since the drive was kicked off on January 16 | Representative photo: iStock

United Kingdom-based pharmaceutical company AstraZeneca has paused the randomised clinical trial of its COVID-19 vaccine after one of the volunteers developed an unexplained illness, the company’s spokesperson said on Tuesday (September 8).

“As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process was triggered and we voluntarily paused vaccination to allow review of safety data by an independent committee,” NDTV quoted the company’s spokesperson as saying.

He, however, clarified that the pause was a routine action, taken to maintain the integrity of the trials.

“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.”


Covishield, developed by the company in collaboration with Oxford University, is one of the three vaccine candidates that are also undergoing human trials in India.

Stating that certain illness are common during large trials, the spokesperson stressed that the same, however will be reviewed independently.

“We are working to expedite the review of the single event to minimise any potential impact on the trial timeline,” he said.