The Serum Institute of India (SII) said on Tuesday that its vaccine candidate for the coronavirus disease (Covid-19) is “safe and immunogenic”.

The company also said that the incident with one of the volunteers during clinical trials was “no way induced by the vaccine”.

“All regulatory, ethical processes and guidelines were followed by the company. The principal investigator DSMB (Data and Safety Monitoring Board) and ethics committee stated it was non-related issue to vaccine trial,” news agency ANI reported, quoting a statement from the SII.

The Pune-based company also said that it has sent a legal notice to a man who claimed he had developed serious side-effects in the human trials. “The legal notice was sent to safeguard the reputation of the company which is being unfairly maligned,” ANI quoted SII as saying.

The man had served a legal notice on SII, claiming to have suffered a virtual neurological breakdown and impairment of cognitive functions, seeking Rs 5 crore in compensation and a halt to the trial.

The SII has collaborated with Oxford University and AstraZeneca Plc in testing Covishield, the vaccine candidate they developed.

Along with SII, the man also named Indian Council of Medical Research, one of the sponsors, and Chennai-based Sri Ramachandra Institute of Higher Education and Research, which administered the vaccine to the man.

The man, according to the notice, suffered acute encephalopathy, a disease that affects the brain, following vaccination and all tests confirmed that the setback in his health was because of the vaccine candidate.

The Drugs Controller General of India (DCGI) had deployed an institutional ethics committee at the implementation site to investigate the adverse event.