Brazil is in talks to buy an additional 20 million doses of the coronavirus vaccine developed by China’s Sinovac Biotech, the governor of Sao Paulo told Reuters in an interview, in a show of confidence in the Chinese shot.

The order, which has not been previously reported, will come on top of the 100m doses of the vaccine, known as CoronaVac, already secured by Sao Paulo’s Butantan biomedical institute, Governor Joao Doria said.

Doria, governor of the country’s wealthiest and most populous state, has been the driving force behind CoronaVac’s testing and rollout in Brazil, bolstering his presidential ambitions and feeding a rivalry with President Jair Bolsonaro.