The Indian anti-Covid vaccine BBV152 (Covaxin *) developed by Bharat Biotech, is “safe and protects against disease”: the efficacy two weeks after the second dose is 77.8% against symptomatic infection. It is one of the data of the interim analysis of the phase 3 randomized controlled study, conducted in India between November 2020 and May 2021 on 24,419 participants aged between 18 and 97 years. The results were published in the journal ‘The Lancet’. In the trial “no serious adverse events related to the vaccine were observed”. Most adverse events were mild and included headache, fatigue, and pain at the injection site, the study authors report.
More research is needed to determine the vaccine’s long-term safety and efficacy, as well as its efficacy against serious illness, hospitalization and death, and also to measure efficacy against the Delta variant and other variants of concern. But in the meantime, the provisional data are positive. BBV152 is an inactivated full virion vaccine, and has recently received approval for emergency use by the World Health Organization (WHO) for those over 18. It is formulated with a new adjuvant and administered in a two-way regimen. doses, 28 days apart. The vaccine can be stored and transported at a temperature between 2 and 8 ° C.
In the trial, patients from different locations were enrolled in 25 Indian hospitals and in the analysis the researchers recorded 24 positive cases among 8,471 people in the vaccinated group and 106 positive cases among 8,502 people in the placebo group, data that suggest an overall efficacy of the vaccine by 77.8%. As for the severe disease, one case was detected in the vaccinated group and 15 in the placebo recipients. However, the authors note that these data are preliminary and more research with a larger sample size is needed to determine efficacy against severe illness and hospitalization.
Analysis of vaccine-induced immune responses showed that it produced a “strong neutralizing antibody response as measured by the neutralizing antibody concentration at day 56 (one month after receiving the second dose),” reads the scientific article. Antibodies induced by BBV152 did not show a significant decrease in neutralization activity against the Alpha variant (B.1.1.7) and marginal reductions against other variants of concern of Sars-CoV-2, including Delta (in a preliminary analysis we calculates that the efficacy is 65% against symptomatic infection) and Gamma.