By Erin Mendell

A Chinese drug regulator gave provisional approval to a Covid-19 vaccine developed by a state-owned company, an official at the agency said, providing a green light for mass inoculation roughly a year after the pandemic first emerged in central China.

The National Medical Products Administration, the country's top drug regulator, approved the vaccine Wednesday evening, Deputy Commissioner Chen Shifei said Thursday. A Beijing-based drug-development unit of China National Pharmaceutical Group Co., known more commonly as Sinopharm, said earlier Wednesday that its shot was found to be 79% effective in protecting against Covid-19 in interim Phase 3 clinical trials overseas.

The vaccine, along with two other homegrown candidates, was earlier approved for emergency use in China. Beijing grants conditional approvals for vaccines that haven't completed clinical trials if it is deemed to be urgent to cope with public health emergencies. The new approval is the first allowing for broader use of a coronavirus vaccine in the country.

Sinopharm has started mass production of the newly approved vaccine, Mao Junfeng, an official at the Ministry of Industry and Information Technology, said Thursday.

Drugmakers must still submit final results after they receive conditional approval. Mr. Chen, the regulatory official, said authorities will keep a close eye on Sinopharm to ensure it carries out its Phase 3 trial as planned.

Under the latest emergency-use campaign, which comes as the Lunar New Year holiday in February approaches, some provinces and cities including Shanghai and Shenzhen have rolled out vaccinations for what authorities have described as key groups: workers in cold-chain logistics, health care, customs, airports, markets, public transport and people traveling abroad. Authorities have been urging people to get inoculated, though it isn't mandatory.

Since that campaign started on Dec. 15, China has inoculated more than three million people with the two-dose shots, Zeng Yixin, vice-minister of China's National Health Commission, said Thursday. During the campaign--and during an earlier vaccination push that took place outside of the clinical trial process beginning in July--less than 1.1% of recipients had a mild fever, and more severe side effects such as allergic reactions were detected in fewer than two out of a million cases.

China plans to inoculate as many as 50 million people ahead of the Lunar New Year holiday with vaccines from Sinopharm and Chinese company Sinovac Biotech Ltd., which also has an experimental vaccine authorized for emergency use, people familiar with the matter said in December.

China has five vaccine candidates in the final stage of clinical trials in 16 countries, according to Xu Nanping, vice minister of China's Ministry of Science and Technology.

A statement on the new Sinopharm results showing 79% efficacy, posted online on Wednesday by subsidiary Beijing Biological Products Institute Co., didn't say which countries they were based on. It also didn't offer details on how the efficacy rate was determined, such as how many participants received a placebo or vaccine.

Detailed data will be released later, a Sinopharm official said Thursday.

Raffaele Huang contributed to this article.

Write to Erin Mendell at erin.mendell@wsj.com

(END) Dow Jones Newswires

12-31-20 0033ET