China’s Sinovac Biotech COVID-19 vaccine, to be produced in partnership with Brazilian Butantan Institute, was 78% effective in a late-stage Brazilian trial, São Paulo’s governor João Doria announced on a press conference on Thursday.

The findings are based on a study led by Butantan involving 12,476 healthcare workers volunteers, with half receiving a placebo and half taking the two-dose vaccine. “All these volunteers had a major risk of infection since they handled with the virus everyday. So this trial is superior regarding COVID-19 exposure,” said Dimas Covas, Head of the Brazilian biomedical center.

The report results comes after Turkish researches in December said that the vaccine was 91.25% efficient based on interim data, according to Reuters. In Turkey, according to Dimas Covas, the trials were not restricted to healthcare workers, unlike Brazil.

Besides being efficient, the Sinovac and Butatan’s vaccine is the only one available for mass immunization in Brazil now, according to Dimas Covas. “Brazil’s health regulator was positive in this first meeting we had, we’re about to have an approval,” said Covas.

None of the volunteers of Brazil’s Coronavac (Sinovac’s vaccine) had hospitalization, said Covas, and about 78% of those that received Coronavac’s shot did not need outpatient care.

Doria said that Brazil has the condition to begin to vaccinate immediately, since there are 10 million ready-made doses stored in São Paulo, pending only Brazil’s health regulator (Anvisa) emergency use approval.

In Latin America, besides Brazil, Chile has supply deals with Sinovac. Indonesia is preparing to roll out Sinovac’s vaccine this month and Turkey, Singapore, Ukraine and Thailand also have deals with with the Chinese pharmaceutical firm to provide doses.