In a boost to the national effort against the COVID-19 pandemic, the world's largest vaccine maker Serum Institute of India (SII) has started the phase two and three bridging trials of the Covovax Covid-19 vaccine candidate in India in a study that would involve 1,600 participants, reports Livemint.

The trials have begun at one of the sites in Pune, and at least one more site Delhi-based Hamdard Institute of Medical Sciences and Research is likely to begin screening for the vaccine candidate as early as upcoming Tuesday (30 March).

It should be noted that Covovax is SII's version of the vaccine developed by United States (US) based Novavax which had earlier this month announced that the vaccine has efficacy as high as 96 per cent against the original strain of the virus, as per the phase three study conducted in the United Kingdom (UK).

The company however has also reported, that its vaccine has an efficacy of 86.3 per cent against the UK mutant variant of the virus. On average, as per the company, the vaccine has an efficacy of 89.7 per cent.

Adar Poonawalla-led SII is already manufacturing pharmaceutical major AstraZeneca's vaccine under the name Covishield in India and is gearing to possibly launch Covovax by August. However, the company is planning to begin stockpiling the vaccine from April onwards to meet future demand.