NEW DELHI: The phase 3 clinical trials for Covid-19 vaccine, developed by Oxford University and AstraZeneca, have been put on hold since Tuesday after a volunteer in the UK, who had received the shot, reported a serious adverse reaction.
The development has caught international attention as the investigational vaccine -- based on an adenovirus which causes the common cold -- is among the front runners in the global race to find a preventive intervention that may bring the pandemic to a halt.
AstraZeneca, the British-Swedish company which has got the licence for the vaccine said that the trials are being paused in the US, UK, South Africa, and Brazil but in India, Serum Institute of India, which has entered into the partnership with the firm, maintained that the ongoing trial will continue.
On Tuesday, as per reports, a participant in the UK, who had been administered the vaccine had been hospitalised after developing transverse myelitis — an inflammatory syndrome that affects the spinal cord and can be caused by viral infections.
However, it’s not clear whether the event was related to inoculation or co-incidental and will be confirmed only after a detailed medical review of the patient.
Back home, SII under whose aegis the vaccine is to be being tried on 1,600 participants across 17 centres said that trials in India will continue, irrespective of the latest development.
“We can't comment much on the UK trials, but they have been paused for further review and they hope to restart soon,” the company said in a statement on Wednesday. “As far as Indian trials are concerned, it is continuing and we have faced no issues at all.”
As per the information gathered by this newspaper, the vaccine has been administered to 100 volunteers in India as of now and the safety data is under review of the data safety monitoring board of the trial before more volunteers are given the shots.
Experts meanwhile said that adverse reactions like the one reported from the UK in the trial “is not a bad thing at all, neither is it uncommon.”
“In large randomised efficacy trials, an investigational drug or vaccine is given to a large heterogeneous population,” said virologist Dr. Shahid Jameel. “Some of these people also have other underlying health conditions and may react adversely. This is exactly why we need large trials before approval.”
He added that the good thing is that there is a system in place to recognise these adverse events and address them—which will build confidence in the trials.