Covid-19: Patna AIIMS to enrol 1,000 volunteers for Covaxin phase 3 trial

The trial is a randomised double-blind placebo control trial, in which half the volunteers will be administered the vaccine and the other half will be given a placebo

The All India Institute of Medical Sciences (AIIMS), Patna, plans to enrol 1,000-1,200 volunteers as part of the third and final phase multi-centric human trial of the Covaxin, the Covid-19 vaccine indigenously developed by Bharat Biotech.

A medic administers Covaxin to a health worker during its trials, at the Gujarat Medical Education & Research Society in Ahmedabad, on November 26.(File photo)

The trial is a randomised double-blind placebo control trial, in which half the volunteers will be administered the vaccine and half will be given a placebo that does not contain the active substance that affects health, said sources associated with the trial.

Since the trial is double-blind, the vaccinated volunteers will not know if they were given the vaccine or a placebo, to rule out bias in issues related to treatment and statistical analysis.

The placebo-vaccine ratio was 1:3 in the first phase trial that focused on safety. It was not given in the second stage, but would be given in 1:1 ratio in the third stage, said sources.

“We hope to begin enrolling healthy volunteers between 18 and 55 years of age from December 2 and commence the third phase trial tentatively from December 5 or 6,” said Dr CM Singh, superintendent of AIIMS,Patna, who is also the principal investigator of the trial.

Volunteers will be given two shots of the vaccine at an interval of 28 days. For the next 194 days, there will be regular follow-ups by medical experts.

“The follow-up sampling to check the level of immunogenicity (amount of antibody produced in a healthy body to fight against the SARS CoV-2 virus, which causes the disease) has to be done on day 14, 28, 42, 104 and 194,” added Dr Singh.

The third phase will exclude volunteers in the first two phases of the trial, they said. As many as 46 volunteers had enrolled here out of the total 375 across different centres during the first phase trial. In the second stage, 44 volunteers enrolled at AIIMS, Patna, out of the 750 across India.