Instituto Butantan, a state-owned biomedical research centre in Brazil, has delivered to the Brazilian Health Ministry another 3.3 million doses of CoronaVac, a vaccine against COVID-19 developed by Sinovac Biotech Ltd of China, Reuters reports, citing the government of the state of São Paulo.

The news agency says the delivery, made on Monday, means Instituto Butantan has now supplied the ministry with 20.6 million CoronaVac doses.

The report says Instituto Butantan is contracted to deliver 46 million doses by the end of April, and to deliver another 54 million by September.

Instituto Butantan and the Brazilian federal government are negotiating the supply of 30 million more doses, for delivery in the fourth quarter of this year, the report says.

At present Instituto Butantan simply puts the active ingredients of Coronavac in vials, but it expects to begin making doses from scratch next year, Reuters says.