The Drugs Controller General of India is conducting an in-depth assessment of the recent incident in which a Chennai-based participant in the trial for the Covishield vaccine developed by the Serum Institute of India sued the company for a “severe adverse affect”, a top scientist at the Indian Council of Medical Research told News18 on Monday.

“The event was reported, an initial assessment has been done and an objective, in-depth scientific assessment by the DCGI [Drugs Controller General of India] is likely to be completed soon,” Dr Samiran Panda said.

He, however, said that the incident which took place in October was duly reported to the institutional ethics committee within 24 hours and to the drugs regulator within seven days, according to News18.

Panda added that the a vaccine trial, which looks at safety and efficacy of a drug, would come across some side effects or adverse effects. “The point is to figure out if the adverse event is linked to the investigational product, in this case the vaccine,” he said.

He pointed out that the central drug regulator had halted the trials a few months back because of “an unexplained illness” in a participant in the United Kingdom. “So, we should wait for DCGI to complete its assessment of the finer details, which is likely to come out soon,” Panda said.

The incident

A 40-year-old participant had sent a legal notice on November 21 and sued Serum Institute for Rs 5 crore. He was administered a dose of the vaccine at Chennai’s Sri Ramachandra Institute of Higher Education and Research on October 1. Copies of his legal notice have also been sent to the Chief Executive of AstraZeneca in the United Kingdom, chief investigator of the Oxford trials and vice-chancellor of Ramachandra Institute.

He alleged that the vaccine triggered an adverse reaction, including neurological impairment.

Serum Institute of India has partnered with the British drugmaker AstraZeneca and the University of Oxford to conduct trials on its vaccine in India and produce it if it secures approval.

The man has demanded that the vaccine trial be immediately halted and all plans for its “manufacture and distribution” be suspended, failing which legal action would be taken. According to the legal notice, there was a total “behavioural change” in the participant and he seemed unaware of his surroundings.

Meanwhile, the Serum Institute of India filed a Rs 100 crore defamation suit against the person on Sunday, calling the allegations “malicious” and “misconceived”.

In a statement, a Serum Institute spokesperson said that while they sympathised with the volunteer’s medical condition, there was “absolutely no correlation with the vaccine trial and the medical condition of the volunteer”.