Hyderabad, Dec 20 : Bharat Biotech has sought the approval of the Drug Controller General of India (DCGI) to conduct Phase 3 trials of its Covid-19 intranasal vaccine, sources said on Monday. The Hyderabad-based vaccine maker has submitted the application and awaiting approval for Phase 3 trials of intranasal vaccine (BBV154). "Intranasal vaccines have the potential to prevent against transmission. An intranasal vaccine as a booster dose will be easier to administer in mass vaccination campaigns," a source told IANS. Sources said Phase 2 trials were conducted with Covaxin and BBV154. "Using a combination of one intramuscular and the other nasal is an innovative approach of heterologous," they said. The intranasal vaccine can be given as booster dose to those who have already taken both the doses of intramuscular vaccines. Health experts say the intranasal vaccine as booster dose will add a key weapon in India's fight against Covid-19, especially when Omicron, the new variant, spreads fast in the country. Bharat Biotech's Covaxin, along with Covishield manufactured by Serum Institute of India, are the two vaccines so far being used in India's current Covid-19 vaccination drive, which was launched in January this year. Russian vaccine Sputnik-V has also been approved for emergency use in India. /IANS