The vaccine induced robust binding and neutralising antibody responses which were comparable to those observed in the convalescent serum collected from patients who had recovered from COVID-19

HYDERABAD: The COVID-19 vaccine by Hyderabad-based Bharat Biotech, COVAXIN, has been found to have a robust immune response, without any severe adverse events, among the people who were immunized with it as part of the Phase-I clinical trials. Also, the vaccine is well-tolerated in all dose groups and it can be stored between 2-8 degree Celsius temperature, which is compatible with all Indian immunization programs. This has been reported in a preprint paper titled 'A Phase 1: Safety and Immunogenicity Trial of an Inactivated SARS-CoV-2 Vaccine-BBV152', available on

The Phase-I clinical trial involved 375 participants of age 18-55 years from diverse geographic locations and socioeconomic conditions, across 11 hospitals. Among the enrolled participants, 100 each were randomized into three vaccine groups who received three different formulations of the vaccine and 75 were part of the control group. The vaccine was administered in two doses, 14 days apart.

The preprint paper mentions that one serious adverse event was reported during the trial in but it was not associated with the vaccine. The patient had tested positive for mild COVID-19 five days after after immunisation. He was admitted to a hospital and discharged after treatment.

According to the preprint paper, "The most common adverse event was pain at the injection site, which resolved spontaneously."

It further said, "The overall incidence rate of local and systemic adverse events in this study was 10%-20% in all vaccine treated arms, which is noticeably lower than the rates for other SARS-CoV-2 vaccine platform candidates and comparable to the rates for other inactivated SARS-CoV-2 vaccine candidates."

In October, Bharat Biotech was given the approval to conduct Phase-III clinical trial of COVAXIN, from the Central Drugs Standard Control Organisation (CDSCO)