SAO PAOLO (REUTERS) - Brazilian health regulator Anvisa said on Monday (Dec 22) it had certified the production standards of CoronaVac, China's Sinovac-produced coronavirus vaccine candidate, which is being tested in Brazil.

Anvisa has certified the quality of Sinovac's production standards, not the vaccine itself.

Brazil's Sao Paulo state has said it will announce on Wednesday if CoronaVac has been found to be effective against the coronavirus.

The Wall Street Journal had earlier reported that CoronaVac has shown to be effective in late-stage trials in Brazil, citing people involved in the vaccine's development.

But Sao Paulo state's Butantan Institute, which is organising the late-stage trials of Sinovac's vaccine CoronaVac in Brazil, said on Monday that any reports on the efficacy of the shot before a Wednesday announcement were "mere speculation."

Brazil is the first country to complete late-stage trials of CoronaVac, which is also being tested in Indonesia and Turkey, the Journal reported.

The results from the Brazil trials put CoronaVac above the 50 per cent threshold that international scientists deem necessary to protect people, the Journal report said.

Butantan is poised on Wednesday to announce CoronaVac's efficacy rate, according to the Journal.

Sinovac did not immediately respond to Reuters' request for comment.

Sinovac and AstraZeneca Plc's vaccine candidates may be ready for use in Brazil by mid-February, the country's health minister said last week.