China has already authorized emergency use of COVID-19 vaccines developed by domestic companies, a senior health official said on Saturday.

Zheng Zhongwei, head of China's COVID-19 vaccine development task force and an official at the National Health Commission, said the emergency use, which is in accordance with the Chinese vaccine management law, allows vaccine candidates to be used for a limited period of time among certain people at high risk of contracting the disease, such as medical workers, front-line pandemic control workers and Customs workers.

Applications for the emergency use of COVID-19 vaccines started on April 4, and after various discussions and evaluations, the central government approved the plan for their use on June 24 and authorized emergency use of the vaccines on July 22, he said in an interview with China Central Television.

This came after a series of measures were set out to ensure that emergency use of the vaccines is well regulated and monitored, he said.

To prevent a possible resurgence of the novel coronavirus pandemic in the autumn and winter, the scope of people allowed to be inoculated will be further increased to ensure that cities can maintain normal functions when a health crisis strikes, he said.

The price of the vaccines will be based on their costs, instead of market demand, Zheng said. "It's not to say that the companies cannot make a profit from the vaccines, but the fundamental rule is that the profit should be moderate and reasonable and based on the costs of making the vaccines."

The production capacity for the vaccines by domestic companies can meet the demand for emergency use and ongoing clinical trials, he added.

Yang Xiaoming, CEO of China National Biotec Group, a subsidiary of China National Pharmaceutical Group (Sinopharm), said the company has signed agreements with several countries on phase three clinical trials of the inactivated vaccine developed by the company over the past months.

"More than 20,000 people have been vaccinated," Yang said. "Vaccine safety is well guaranteed and its effectiveness is being closely monitored."

The launch ceremony of the phase three clinical trials in Argentina of the inactivated COVID-19 vaccine developed by the company was held in Beijing on Friday after CNBG obtained approval for the process.

The inactivated vaccine also received approval for phase three clinical trials in the United Arab Emirates on June 23, and in Peru and Morocco on Thursday.

On June 16, CNBG announced that the phase one and phase two clinical trials of its inactivated vaccine had demonstrated good performance in safety and effectiveness on vaccinated volunteers. No subjects showed serious adverse reactions, the company said.

According to the World Health Organization, by Aug 6, six vaccine candidates have started phase three clinical trials, with three developed by China.