2 doses of the India-developed vaccine BBV152 offer 77.8% protection against symptomatic COVID-19 disease.
Phase 3 trial reports of the COVID-19 vaccine BBV152 found 2 doses to be 77.8% effective against symptomatic COVID-19 infection, according to a report by The Lancet.
BBV152 is a Vero cell-derived, inactivated whole virion vaccine developed by Bharat Biotech in India. BBV152 was recently granted emergency use approval by the World Health Organization (WHO) for adults 18 years and older.
The phase 3 trial ran from November 16, 2020-May 17, 2021, and included participants 18-97 years old. Trial participants were given 2 doses of either BBV152 (n=12221) or placebo (n=12198). Participants considered to be at high risk for COVID-19 infection were prioritized, with 2750 participants above 60 years of age and 5724 participants at least 1 preexisting condition included in the study. Participants were recruited from 25 hospitals across India for geographic diversity.
At least 2 weeks after the second dose, there were a total of 24 positive COVID-19 cases in the vaccine group (n=8471) and 106 cases in the placebo group (n=8502). 16 cases among the trial participants were qualified as severe symptomatic COVID-19 disease
BBV152 was well-tolerated by all trial participants; 12% of both groups reported an adverse event, with no significant difference in the number of events between the placebo and BBV152 groups. No severe adverse events or deaths were reported, and most common side effects were headache, fever, fatigue, and injection site pain. Long-term safety monitoring will continue for 1 year after administration of the first dose of BBV152.
BBV152 induced a strong neutralizing antibody response, as measured by the concentration of neutralizing antibodies at day 56 (1 month after the second dose). There was no significant decrease in BBV152 antibodies against the Alpha variant (B.1.1.7), but there were marginal reductions in neutralizing activity against Delta and Gamma variants. There was no significant difference in immune response among participants above and below the age of 60.
BBV152 is formulated with a novel adjuvant and in administered in 2 doses, 28 days apart. The vaccine is transported and stored between 2-8°C with a 28-day multi-dose open vial policy.
Due to a limited number of COVID-19 cases in participants in between the first and second dose, investigators were not able to determine vaccine efficacy after 1 dose of BBV152. The study based exclusively in India and is therefore limited by its lack of racial and ethnic diversity. The study also lacked groups such as pregnant women, people living with HIV, and people with severe comorbidities.
A preliminary analysis of the Delta variant found BBV152 to be 65% effective against symptomatic COVID-19. Further research is needed to determine BBV152’s long-term safety and efficacy, effectiveness against Delta and any subsequent COVID-19 variants, and its protection against severe disease, hospitalization, and death.