Vaccine candidate produced ‘high levels of neutralising antibodies’ in Phase 1 trial
COVID-19 vaccine candidate Covaxin, being developed by Bharat Biotech and Indian Council of Medical Research (ICMR), showed tolerable safety outcomes and enhanced humoral and cell-mediated immune responses, according to interim findings of Phase II trials shared in a pre-print paper.
In Phase 1 trial, the vaccine candidate produced “high levels of neutralising antibodies that remained elevated in all participants three months after the second vaccination.”
Titled ‘Safety and immunogenicity clinical trial of an inactivated SARS-CoV-2 vaccine, BBV152 (a phase 2, double-blind, randomised controlled trial) and the persistence of immune responses from a phase 1 follow-up’, the paper was shared on medRxiv, a free online archive and distribution server for complete but unpublished manuscripts (pre-prints) in the medical, clinical, and related health sciences.
“The safety profile of BBV152 is noticeably lower than the rates for other SARS-CoV-2 vaccine platform candidates. The 6 microgram Algel-IMDG formulation was selected for the phase 3 efficacy trial,” the paper said. Pre-prints are preliminary reports of work that have not been certified by peer review.
Phase III trials for Covaxin got underway last month. The Hyderabad-based Bharat Biotech on Tuesday had said that 13,000 of the 26,000 volunteers, who will be part of Phase III trials, had been recruited.
The paper said Phase II was a double-blind, randomised, multi-centre trial that involved 380 healthy children and adults. No serious adverse events were reported in this study.
“The most common adverse event was pain at the injection site, followed by headache, fatigue and fever. No severe or life threatening (Grade 4 and 5) solicited adverse events were reported. After any dose, the combined incidence rate of local and systemic adverse events in this study 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,” the paper said.
It is hypothesised that the humoral and cell-mediated responses reported in the study may persist until at least 6-12 months after the second vaccination dose, the authors said.