BRASILIA (REUTERS) - Brazil's health regulator Anvisa on Wednesday (June 9) authorised phase one and two clinical tests to be carried out on volunteers for the Butanvac vaccine developed by Sao Paulo's Butantan Institute biomedical centre.

The tests for the two-shot vaccine were initially authorised for 400 volunteers, but will later involve an expected total of 6,000 volunteers aged 18 and over, Anvisa said.

The vaccine developed by Butantan, one of Brazil's two top biomedical research centres, will not need imported active ingredients like the main vaccines produced in Brazil, the AstraZeneca shot and Sinovac Biotech's CoronaVac.

Sao Paulo state governor Joao Doria, celebrating the Anvisa authorisation on Twitter, said Butantan has seven million doses of Butanvac ready.