BRASILIA, Oct 19 (Reuters) - An experimental vaccine against COVID-19 developed by China's Sinovac Biotech proved to be safe after its two doses were applied to volunteers in Brazil, according to preliminary results of a late stage clinical trial by Sao Paulo's Butantan Institute.

The institute's director Dimas Covas said on Monday that Coronavac was the safest of the vaccines being tested in Brazil, though data on how effective it is in protecting people against the new coronavirus is not ready yet.

(Reporting by Anthony Boadle; Editing by Christian Plumb)