Johannesburg : Chinese pharmaceutical company Sinovac Biotech on Friday launched the Phase III clinical trial of its Covid-19 vaccine on a group of children and teenagers between six months and 17 years old in South Africa. The study, carried out in collaboration with South African company Numolux Group, has enrolled approximately 2,000 participants in the country, who will receive two doses of Sinovac's CoronaVac vaccine or a placebo, 28 days apart. The efficacy assessment will be based on relevant indicators, the Xinhua news agency reported. Numolux CEO Hilton Klein said that there are roughly 24 million children and teenagers in South Africa, and that if the vaccine made by Sinovac is approved for use on them, it will help the country reach herd immunity more quickly. The South African Health Products Regulatory Authority authorised the use of the CoronaVac vaccine on the country's adults in July.