The Serum Institute of India on Tuesday once again dismissed the claims of a Chennai volunteer who said he had faced “severe adverse effects” due to the trials of its potential coronavirus vaccine Covishield. The drug manufacturer said that the vaccine was “safe and immunogenic” and was not the reason behind the complications faced by the volunteer.

“The incident with the Chennai volunteer, though highly unfortunate, was in no way induced by the vaccine and Serum Institute of India is sympathetic with the volunteer’s medical condition,” the company claimed.

The Pune-based firm also said that it had followed “requisite regulatory and ethical processes and guidelines” during the administering of the vaccine.

The statement said that it had informed about the incident to officials of the Data and Safety Monitoring Board and the Ethics Committee, who cleared it as a “non-related issue to the vaccine trial”. A report and data on the incident were then submitted to the Drugs Controller General of India, and the trials were continued only after the “required processes” were cleared, Serum Institute said.

It reiterated that the legal notice sent by the volunteer maligns the reputation of the company and assured that the vaccine will not be released until it is proven to be immunogenic and safe.

On Sunday, after the volunteer levelled the charges against Serum Institute, the company filed a Rs 100 crore defamation suit, calling the allegations “malicious” and “misconceived”.

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 volunteer 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 a senior scientist at the Indian Council of Medical Research on Monday said that the Drugs Controller General of India was assessing the incident and it was expected to be completed soon. Dr Samiran Panda said that 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.