China has revealed the inoculations of 22.8 million Chinese with indigenously developed COVID-19 vaccines since it first clandestinely began immunizations in July 2020. This number is the world's largest.

The revelation was made by the National Health Commission (NHC), the executive department that formulates China's national health policy, which also said those vaccinated thus far belong to "essential groups."

"Overall, the work is progressing in a smooth and orderly manner," said NHC vice director Dr. Zeng Yixin Wednesday.

NHC earlier said China intends to vaccinate some 50 million citizens before the Lunar New Year, which starts Feb. 12. It said priority in vaccinations is being given to essential groups such as workers in medical, transport and food services, employees and students going abroad.

In December, China began vaccinating high-risk groups as the more dangerous winter months set in and expects to produce more than 1 billion doses of its three candidate vaccines this year. Since July, however, China had unofficially vaccinated millions of Chinese with these vaccines despite these vaccines' safety and efficacy not being proven by Phase 3 clinical trials.

Zeng said Chinese working in health care, customs, wholesale and seafood markets, public transportation, and the cold-chain industry will be among the first to be inoculated. He said that as the temperatures grow much colder in winter and spring, China will have to struggle harder to prevent the spread of COVID-19. Under these conditions, vaccinating key population groups will greatly boost prevention efforts.

Zeng said the December vaccinations were the first step in China's COVID-19 vaccination plan. Vaccination programs for senior citizens, people with underlying diseases, and the general public will be carried out in late 2021 after China's COVID-19 vaccines enter the market and production ramps-up.

Despite the absence of phase 3 trial data, NHC said the emergency use of the three COVID-19 vaccines showed no severe adverse effects on those inoculated. In late November, China said it had vaccinated close to a million of its citizens since July.

Dr. Zheng Zhongwei, director of the NHC's science and technology development center, said NHC authorized the emergency use of China's vaccines July 22. He justified the decision to begin inoculating certain groups even as the vaccine is still undergoing phase-3 testing as "in line with the law."

Those vaccinated were medical staff, border inspection officials and other essential workers.