The authorities in Brazil are discussing with Sinovac Biotech Ltd of China the acquisition of 20 million more doses of CoronaVac, a vaccine against COVID-19 developed by the company, Reuters reports.

The news agency quotes Governor Joao Doria of the Brazilian state of São Paulo as saying that Instituto Butantan, a state-owned biomedical research centre in Brazil, had already secured 100 million doses of CoronaVac, but that more were being negotiated.

Instituto Butantan was in charge of the mass clinical testing of CoronaVac in Brazil, and it now finishes the production of doses meant for the Brazilian Health Ministry.

Mr Doria said Instituto Butantan expected to receive from China every week or 10 days shipments of the active ingredients for making CoronaVac.

The centre is building a factory in Brazil where it will begin producing the active ingredients next year, Reuters says.