COVAXIN phase 2 data published in Lancet; vaccine safe, induced high neutralising antibody

By Sahil Pandey
New Delhi [India], March 9 : British medical journal The Lancet on Tuesday published the phase 2 results of the "Made in India" COVID-19 vaccine, COVAXIN, stating that the vaccine has better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial. No severe or life-threatening adverse events were reported, it added.
Report named as Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: interim results from a double-blind, randomised, multicentre, phase 2 trial and 3-month follow-up of a double-blind, randomised phase 1 trial published the assessment.
"The reactogenicity assessments reported in this study were substantially better in the phase 2 trial than the phase 1 trial and other trials with a placebo group. Additionally, the proportion of participants reporting adverse events in the phase 2 trial were lower than in the phase 1 trial," Lancet report says.
Describing the outcome in terms of adverse effect, Lancet said "Most common adverse event in the phase 2 trial was pain at the injection site, followed by headache, fatigue, and fever. No severe or life-threatening (i.e., grade 4 and 5) solicited adverse events were reported. No significant differences in safety were observed between the two groups."
According to the journal, the phase 1 trial, BBV152 induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination.
"In the phase 2 trial, the Bharat Biotech vaccine showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial," it said.
No cases of COVID-19 were reported in either group of the phase 2 trial, whereas one case of symptomatic COVID-19 was reported in the Algel-only control group of the phase 1 trial.
According to the report, "To ensure generalisability of the results, this study included participants from diverse geographic locations, enrolling 380 participants across nine hospitals across nine states in India. Based on follow-up data from the phase 1 trial, despite a marginal expected decline in neutralising antibody titres at day 104, BBV152 has shown the potential to provide durable humoral and cell-mediated immune responses."
In phase 2, the first dose administered on day 0 and the second dose on day 28.
Bharat Biotech earlier released results of Phase 3 clinical trials of its coronavirus vaccine Covaxin, with the drug demonstrating 81 per cent interim efficacy against Covid-19.
"The whole virion inactivated COVID-19 vaccine candidate demonstrated an interim vaccine efficacy of 81 per cent in its phase III clinical trial. The trials involved 25,800 subjects, the largest ever conducted in India, in partnership with the Indian Council of Medical Research (ICMR), the biotech company said in a release.
The company said the phase III study enrolled 25,800 participants between 18-98 years of age, including 2,433 over the age of 60 and 4,500 with co-morbidities.
"The primary endpoint of phase III clinical trial is based on the first occurrence of PCR-confirmed symptomatic (mild, moderate, or severe) Covid-19 with onset at least 14 days after the second study vaccination in serologically negative (to SARS-CoV-2) adult participants at baseline," it stated.