COVAXIN booster dose trial demonstrates long-term safety with no serious adverse events: Bharat Biotech

By Shalini Bhardwaj
New Delhi [India], January 8 : Covaxin manufacture Bharat Biotech on Saturday said that the booster dose trials have shown "promising results" of long-term safety with "no serious adverse events".
The Hyderabad-based company announced the results on the safety and immunogenicity of COVAXIN (BBV152), a whole-virion inactivated COVID-19 vaccine as a booster dose.
"Covaxin trial demonstrated long-term safety with no serious adverse events. 90 per cent of recipients had a detectable neutralizing antibody response against the wild-type strain (six months after the second dose)," Bharat Biotech said in an official statement.
The frequency of adverse events was found to be lower than vaccines from other manufacturing platforms, it added.
Six months after receiving the second dose, the participants received a third booster dose.
"Neutralization titers against wild-type and Delta variants were five times higher than after a two-dose schedule," the firm said.
The analysis showed, six months after a two-dose BBV152 vaccination series cell-mediated immunity and neutralizing antibodies to both homologous (D614G) and heterologous strains (Alpha, Beta, Delta, and Delta plus) persisted above baseline, although the magnitude of the responses had declined.
"The booster dose led to a pronounced increase in CD4 and CD8 responses. This many allow Covaxin to confer long term protective efficacy against severe SARS-CoV-2," the drugmaker said.
It also said that the frequency of adverse events was "lower than vaccines from other manufacturing platforms."
Furthermore, neutralizing antibodies against homologous and heterologous SARS-CoV-2 variants increased 19 to 265 fold after a third vaccination. Booster BBV152 vaccination is safe and may be necessary to ensure persistent immunity to prevent breakthrough infections.
Dr Krishna Ella, Chairman and Managing Director of Bharat Biotech, said, "These trial results provide a strong foundation towards our goal to provide COVAXIN®[?] as a booster dose. Our goal of developing a global vaccine against COVID-19 have been achieved. COVAXIN is now indicated for adults, children, 2 dose primary and booster doses. This enables the use of COVAXIN®[?] as a universal vaccine."
While protection against the severe disease remains high across the full 6 months, a decline in efficacy against symptomatic disease over time and the continued emergence of variants are expected. Based on emerging data, Bharat Biotech believes that a third dose may be beneficial to maintain the highest levels of protection.
COVAXIN is formulated uniquely such that the same dosage can be administered to adults and children alike. COVAXIN®[?] is ready-to-use a liquid vaccine, stored at two-eight degrees Celcius, with 12 months shelf life and a multi-dose vial policy. The same vaccine can also be used for two-dose primary immunization and for booster dose vaccinations, making it truly a universal vaccine.