Covaxin well-tolerated: Phase 1 peer-review

Phase 1 clinical trials are mostly used to test safety of a vaccine and the effects of various doses and combinations. The company found that there was no significant difference in the highest dose it tested as compared to the lowest, making the case for the higher dose to be used.

Bharat Biotech Covaxin was well tolerated with no vaccine-related serious adverse events in a small group of volunteers, according to a peer review of the company’s phase 1 clinical trials published in the journal Lancet Infectious Diseases on Friday.

Hundreds of thousands of people have already received it, and experts believe the controversy around Covaxin still not clearing adequate levels in trials may be contributing to hesitancy. (Reuters/ File photo)

“…BBV152(Covaxin) led to tolerable safety outcomes and enhanced immune responses… BBV152 induced binding and neutralising antibody responses that were similar to those induced by other SARS-CoV-2 inactivated vaccine candidates,” the study said, in line with the data preprint data released by the company.

Phase 1 clinical trials are mostly used to test safety of a vaccine and the effects of various doses and combinations. The company found that there was no significant difference in the highest dose it tested as compared to the lowest, making the case for the higher dose to be used.

The overall incidence of solicited local and systemic adverse events in this study was 14–21%. The most common adverse event was pain at the injection site, followed by headache, fatigue, and fever.

Between July 13 and 30, 2020, 827 participants were screened, of whom 375 participants were randomized equally to receive three vaccine formulations in groups of 100 each (doses were as 3ug with Algel-IMDG, 6ug with Algel-IMDG or 6ug with Algel) while the control group had 75 participants. Algel and Algel-IMDG refer to different kinds of adjuvants -- additives that are designed to enhance immune response.

The whole-virion inactivated virus vaccine has been made in collaboration with the Indian Council of Medical Research (ICMR). The vaccine is still in phase 3 trials -- where it is being tested in over 25,000 people for safety and efficacy -- but has been approved for emergency use. The other vaccine, Covishield, has safety and efficacy data from phase III trials.

Hundreds of thousands of people have already received it, and experts believe the controversy around Covaxin still not clearing adequate levels in trials may be contributing to hesitancy. On Thursday, centres administering Covishield showed over 75% turnout while in those with Covaxin, less than 30% turned up.

“13,000 volunteers have been successfully administered the 2nd dose in the phase 3 clinical trials of Covaxin. My heartfelt thanks to all of them for their pro-vaccine public health volunteerism,” said Suchitra Ella, joint managing director, Bharat Biotech International Ltd.