The chairman of Chinese biopharmaceutical company Sinovac Biotech (Sinovac), Yin Weidong, said on 13 January 2021 that the company's unit, Sinovac Life Sciences, could double annual production capacity of its CoronaVac COVID-19 vaccine to one billion doses by February 2021, Reuters news agency reported on Wednesday.

Yin told a press conference that over seven million doses of CoronaVac vaccine, one of the three China has included in its emergency vaccination programme, have so far been supplied to regions, including the city of Beijing and Guangdong province.

While the first phase of Sinovac Life Sciences' existing production line can make 500 million CoronaVac doses in one year, another with annual capacity of 500 million doses could become operational by February, Yin said.

Researchers in Brazil on Tuesday released new efficacy data for the vaccine, for which there have been varying rates of success from trial sites in three countries.

However, Yin said that trials in different countries are designed differently, but the CoronaVac doses being tested came from the same batch.

"These Phase III clinical trial results are sufficient to prove that CoronaVac vaccine's safety and effectiveness are good around the world," Yin was quoted as saying.

An official of China's National Health Commission told reporters that China has given over 10 million COVID-19 doses so far, Reuters added.