Sao Paulo’s Butantan biomedical institute announced on Friday it is developing a “100 percent Brazilian” vaccine against Covid-19 and expects to start using it in July. Butantan is the largest vaccine producer in Brazil and makes the Corona Vac shot produced by Chinese firm Sinovac — the most widely used against the pandemic in the South American country. ButanVac will also be produced in Thailand and Vietnam and distributed to poorer countries. “Theresults in pre-clinical tests were excellent,” said Butantan director Dimas Covas. The vaccine needs to be authorized by Brazil’s vaccine regulator Anvisa before it can start clinical trials in April.