KOCHI - Serum Institute of India has threatened to file a defamation suit against a participant who reported having adverse reactions after receiving a dose of the company's test Covid-19 vaccine during the clinical trial in India.
An official at the Indian Council of Medical Research (ICMR), a co-sponsor of the vaccine trial along with Serum Institute, said that the Drug Controller General of India (DCGI) is inquiring into whether the volunteer's illness is linked to the vaccine under study.
"The DCGI, India's regulatory authority, will finally determine if the vaccine is safe… Until it's known if the serious adverse event is causally associated to the vaccine or not, we cannot reach any decision. That link is not established yet," said Dr Samiran Panda, the chief of ICMR's Epidemiology & Communicable Diseases Division.
A 40-year-old trial participant was admitted in a Chennai hospital for 15 days in October after experiencing severe neurological reactions 10 days after getting a dose of Covishield, as the vaccine manufactured by the Pune-based Serum Institute is called.
The vaccine technology was developed by Oxford University and UK-based AstraZeneca, and Serum Institute is conducting a Phase II/III trial on 1,600 human volunteers in India. The privately-owned Indian company is the world's largest vaccine manufacturer.
Dr S. Ramakrishnan, the principal investigator who administered the vaccine in Chennai on Oct 1, confirmed with The Straits Times that the patient was treated from Oct 12 to 26 at the same hospital where he received the vaccine.
The man, a marketing consultant, was diagnosed after multiple tests with acute encephalopathy, which alters brain function and causes personality change, memory loss, and declining ability to reason or concentrate. The patient's wife said he is now recovering at home but suffers from weakness and mild mood swings.
Dr Ramakrishnan said that after he reported the adverse event within 24 hours to the trial sponsors, they "unblinded the trial".
He admitted that the patient had not received a placebo, but the study vaccine, but maintained that illness was "unrelated to the vaccine" and that the local institutional ethics committee agreed with him in its initial assessment report.
"When we discharged the patient, I told the family that radiologically there was no evidence of (the encephalopathy) being related to the vaccine," added Dr Ramakrishnan.
But the participant's wife said the family was not informed.
"The hospital did many tests and bore all the costs, but they were trying to find some reason for my husband's illness that was not the vaccine. Even the hospital's discharge summary didn't mention the vaccine under medication history," she said.
The discharge summary, a copy of which ST has seen, lists existing gastroenteric issues and a hair-loss tablet the patient has taken for a year, but not the trial Covid vaccine dose the participant received 10 days prior to falling ill.
The participant's family filed a legal notice against the company and India's drug regulator on Nov 21, demanding a compensation of 50 million rupees (S$903,850) and that the vaccine trial be stopped until the government investigation shows it is safe.
Serum Institute on Sunday (Nov 29) dismissed the participant's allegation as "malicious and misconceived". In a statement, the company said it would seek damages in excess of a billion rupees.
Dr T Jacob John, a leading virologist and former professor at the Christian Medical College, Vellore, said the Serum Institute's statement was "completely out of line".
"The company cannot prematurely declare that the adverse event is not related to the vaccine until the official agency concludes its evaluation. The Covishield vaccine is one the world's front-running vaccines and will touch millions… The adverse event should have been in the public domain by mid-October when the man was hospitalised," Dr John said.
In September, after two participants in the AstraZeneca vaccine trial in the United Kingdom suffered adverse events, regulators worldwide paused the vaccine trials including in India. They resumed only after investigations concluded that the adverse events in the UK were unrelated to the vaccine.
India's regulator even had the consent forms for the trials in India modified to include the UK's adverse events, for full disclosure.
"Why has the Indian regulator not been able to complete adjudication of the event in over 1.5 months and while it is pending, why not halt the trial, inform trial participants and the public?" asked Ms Malini Aisola, co-convenor of All India Drug Action Network, a civil society organisation.
On Nov 28, Mr Adar Poonawalla, whose family founded the Serum Institute, held a online press conference after Prime Minister Narendra Modi visited the company's Pune facilities as part of a tour of three vaccine manufacturers in the country.
"Covishield vaccine supplies will be first for distribution in India, followed by Covax countries, mainly Africa," said Mr Poonawalla. Covax Facility is a global procurement mechanism to develop and distribute new Covid-19 vaccines in 172 countries and is coordinated by the vaccine alliance Gavi.
This month, Bangladesh agreed to buy 30 million doses of the vaccine candidate from Serum Institute.
While he did not address questions about the adverse event, Mr Poonawalla said his company was producing 50-60 million doses of Covishield a month, and was aiming at building facilities that can "handle over a billion doses a year."
They will apply to the Indian government for an emergency license in the next two weeks.