Disregarding accepted medical convention, two Chinese biotech firms have injected hundreds of thousands of Chinese with their new COVID-19 vaccines still undergoing clinical trials and that haven't been proven safe and effective.

China National Biotec Group Company (CNBG), a subsidiary of state-owned Sinopharm, and Sinovac Research and Development Co., Ltd. both admitted to highly irregular procedures that flout global medical guidelines. CNBG said it used two of its untested vaccines in these mass inoculations.

Starting late July, hundreds of thousands of Chinese were inoculated with both CNBG's vaccines. The secret inoculations were later acknowledged by the National Health Commission (NHC).

The agency said this vaccine was administered to medical staff, border inspection officials and other essential workers. Zheng Zhongwei, director of the NHC's science and technology development center, said the central government in Beijing authorized the "emergency use" of the vaccine on July 22.

He justified the decision to begin inoculating certain groups even as the vaccine is still being tested is "in line with the law."

On the other hand, Sinovac said it has inoculated 3,000 of its employees and their family members, including the CEO, with its candidate vaccine.

These acknowledgements means three made in China candidate vaccines have now been tested on the general population despite these vaccines remaining unproven.

NHC said the three vaccine candidates are still undergoing Phase 3 clinical trials, which involve testing a vaccine's safety and efficacy on tens of thousands of people.

Four of the 10 vaccine candidates currently undergoing phase 3 testing around the world are manufactured by Chinese pharmaceutical firms.

The Chinese vaccines are an inactivated vaccine from the Wuhan Institute of Biological Products; the CoronaVac vaccine from Sinovac being tested in Brazil and Russia; the Ad5-nCoV from CanSino Biologics being tested in Russia and one CNBG vaccine.

Six other COVID-19 vaccine candidates from other countries are also in phase 3, the final testing phase before vaccine production, according to the World Health Organization (WHO).

China's decision to approve the use of unproven vaccine candidates shows it has confidence in the vaccines' safety and efficacy, claims Zhao Dahai, a public health professor at Shanghai Jiao Tong University.

"It tells the world that we are not playing with the lives of the foreign volunteers taking part in the clinical trials," he said. "We are quite sure of their safety."

It is up to medical regulators in individual countries to determine whether to let the general public use a vaccine only after its testing is complete. Administering a vaccine candidate while clinical trials are incomplete are dangerous and might lead to loss of lives.