China National Biotec Group (CNBG), a unit of state-owned pharmaceutical giant China National Pharmaceutical Group (Sinopharm), also said it had obtained emergency use approval for a coronavirus vaccine candidate in social media platform WeChat on Sunday.

CNBG, which has two vaccine candidates in phase 3 clinical trials, did not say which of its vaccines had been cleared for emergency use.

China has been giving experimental coronavirus vaccines to high-risk groups since July, and a health official told state media in an interview aired last week that authorities could consider modestly expanding the emergency use programme to try to prevent possible outbreaks during the autumn and winter.