The Subject Expert Committee of the Drug Controller General of India (DCGI), has granted in-principle approval to Bharat Biotech for the conduct of phase 3 Superiority Study and Phase 3 booster dose study for the intranasal Covid-19 vaccine.

Bharat Biotech will conduct trials on over 5000 subjects (50 per cent vaccinated with Covishield and 50 per cent with Covaxin), to check the efficacy of the Covaxin booster dose. Like other countries the booster dose will be given six months after the second dose.

Earlier last month, AstraZeneca also announced that their Covid-19 vaccine significantly boosted levels of antibodies against the Omicron SARS-CoV-2 variant following a third dose booster, according to data from a new laboratory study.

Neutralisation titres for Omicron were boosted following a third dose with Vaxzevria compared to titres after a second dose. The levels seen after the third dose booster were higher than the neutralising antibodies found in individuals who had been previously infected with and recovered naturally from Covid-19 (Alpha, Beta, Delta variants and original strain). Sera obtained from individuals one month after receiving the third dose booster vaccination neutralised the Omicron variant to levels that were broadly similar to those observed one month after the second dose against the Delta variant. Two doses of Vaxzevria have been associated with protection against the Delta variant in real world studies.

The study analysed blood samples taken from individuals infected with Covid-19; those who had been vaccinated with a two-dose schedule and a third dose booster; and those who had reported previous infection from other Covid-19 variants of concern. The study included samples from 41 individuals who had received three doses of Vaxzevria.