State-backed vaccine developer China National Biotec Group Co. said one of its shots is effective in preventing COVID-19 in 79.3 per cent of people, allowing it to apply for authorization to market the inoculation for use in the general population.

The interim data shows the vaccine, which is already authorized for emergency use in China, is safe and people who took the shots in the trial all generated high levels of antibodies, according to a statement posted on the website of Beijing Biological Products Institute Co., a subsidiary of CNBG’s parent Sinopharm.

The rate for the vaccine -- one of two developed by CNBG -- meets the minimum standard of 50 per cent efficacy set by U.S. regulators for emergency authorization of COVID vaccines. However, vaccines using cutting-edge messenger RNA technology from Moderna Inc. and Pfizer Inc. have produced far better results, reducing symptomatic COVID cases by well over 90 per cent in giant trials.

The rate announced Wednesday for the CNBG shot is also lower than what was reported from trials in the United Arab Emirates, which put the protection level at 86 per cent.

A state-owned drugmaker that has a dominant share of China’s vaccine market, CNBG in April was among the world’s first to push experimental shots to the crucial final stage of human testing. The company’s research institutes developed two shots using an inactivated version of the virus to stimulate immune response, an approach widely adopted by many of the existing vaccines used to prevent illness around the world.

Such vaccines have the advantage of easier storage and distribution as they don’t need to be frozen -- unlike the experimental mRNA vaccines being developed by Pfizer and Moderna. CNBG’s shots can be stored at normal refrigerator temperatures, making distribution to rural areas and developing countries easier.

CNBG has vaccine supply agreements with several developing countries including Malaysia, Brazil, Pakistan and the UAE, according to public reports compiled by Bloomberg. Leading Western developers like AstraZeneca Plc and Pfizer have inked agreements with far more countries.

Despite the fact that China’s vaccines haven’t yet received regulatory approval for widespread use, doses have already been given to hundreds of thousands of people in China under an emergency-use program in place since mid-year. That has raised concern among scientists of potential risks in using shots whose safety has yet to be thoroughly studied.