The superpower launched a vaccine emergency use program in July, offering three experimental shots developed by a unit of state pharmaceutical giant China National Pharmaceutical Group (Sinopharm) and US-listed Sinovac Biotech.

A fourth COVID-19 vaccine being developed by CanSino Biologics was approved for use by the Chinese military in June.

Aiming to protect essential workers and reduce the likelihood of a resurgence, the vaccines are also grabbing attention in the global scramble by governments to secure supplies, potentially helping reframe China's perceived role in the pandemic.

Beijing has not released official data on the uptake in domestic targeted groups, which include medical, transport and food market workers.

But China National Biotec Group (CNBG), the Sinopharm unit developing two of the emergency use vaccines, and Sinovac have confirmed at least tens of thousands of people have been inoculated.

Additionally, CNBG said it had given hundreds of thousands of doses; one of its vaccines requires an individual receive two or three shots to be inoculated.

Beijing has engaged a public, top-down approach to endorse the experimental vaccines and foster community support.

Among those lining up for shots early on were the chief executives of Sinovac and Sinopharm and the military's research chief.

The chief biosafety expert at the Chinese Center for Disease Control and Prevention (CDC) revealed this week she too had been injected in April as she announced the potential that at least some of the vaccines would be ready for public use as early as November.

"So far, among the people who who were vaccinated, no one has been sick with the disease," Guizhen Wu said on state TV.

"So far, (the vaccination scheme) works very well. No side effect occurred."

Wu's comments were broadly in line with comments by CNBG last week that none of tens of thousands of people who travelled to high-risk countries and regions after being vaccinated had been infected and there was "no case of obvious adverse reaction".

China's approach runs counter to that of many Western countries, where experts have warned against authorising the emergency use of vaccines that have not completed testing, citing a lack of understanding about longer-term efficacy and potential side effects.

Anna Durbin, a vaccine researcher at Johns Hopkins University, described China's emergency use program as "very problematic," saying it was impossible to judge efficacy without a clinical trial standard control group.

Russia is one of the few other countries to authorise the use of an experimental vaccine, making its own "Sputnik V" vaccine mandatory for certain groups including teachers.

India is considering emergency authorisation for a vaccine, particularly for the elderly and people in high-risk workplaces.

Australian Associated Press