SAO PAULO : The governor of Brazil's São Paulo state said on Wednesday that Phase 3 clinical trials of a potential COVID-19 vaccine developed by China's Sinovac Biotech Ltd have shown promising results and it may be available to Brazilians as early as December.Governor João Dória added that Phase 2 trials of the potential vaccine had shown an immune response of 98% in the elderly.Some 9,000 Brazilians are participating in the Sinovac vaccine trials, which are being conducted by the Butantan Institute in Sao Paulo city, the state capital.Brazil, which has the third worst outbreak of the novel coronavirus in the world after the United States and India, has become a testing ground for at least two vaccine candidates.One such vaccine is being.