BEIJING - China National Biotec Group (CNBG) said on Wednesday it has completed construction of a new plant for coronavirus vaccines, doubling its capacity to more than 200 million doses a year, as it prepares late-stage trials of its potential COVID-19 shots.

CNBG, a unit of the state-owned China National Pharmaceutical Group (Sinopharm), has two COVID-19 vaccine candidates in human trials and plans a large-scale Phase 3 human testing in the United Arab Emirates. 

Its newly built plant in Wuhan, the epicentre of China's coronavirus outbreak that started last year, has annual capacity of more than 100 million doses, and adds to its Beijing-based facility whose construction was completed in April.

These plants were built "at a war-time speed", the company said in a post on Chinese social media WeChat.

No vaccine against a virus that has killed over half a million people has been approved for commercial use yet.

But developers globally have been rushing to get factories ready for large-scale production.

The Coalition for Epidemic Preparedness Innovation, an influential foundation which is backing nine candidates including those developed by Inovio and Moderna, said it has identified manufacturers with capacity to produce four billion doses a year and is confident of making two billion by the end of 2021. 

Another Chinese vaccine developer Sinovac started around end-March to build a coronavirus vaccine plant, which it hopes will be ready this year and capable of making up to 100 million shots a year. 

(Reporting by Roxanne Liu and Ryan Woo; Editing by Miyoung Kim & Simon Cameron-Moore) ((hongkong.newsroom@thomsonreuters.com; (8610)6627-1277; Reuters Messaging: roxanne.liu@thomsonreuters.com))