China has offered experimental coronavirus vaccines to aviation industry workers, according to a regulatory notice seen by Reuters, in a push to inoculate high-risk groups to prevent a possible resurgence as economies reopen.

China, which has four COVID-19 vaccines in the final stage of human trials, launched the emergency use vaccine program in July, hoping to boost the immunity of groups such as border inspectors or medical industry workers.

Frontline workers at Chinese airlines, airports, China National Aviation Fuel Group, and TravelSky Technology Limited will be provided a candidate vaccine voluntarily, the notice from China's aviation regulator shows.

The Civil Aviation Administration of China has asked these sectors and firms to compile a list of personal information of employees willing to take the vaccine, the notice adds.

The vaccination is "in response to a possible second wave of infections erupting in the fall and winter, and to the huge pressure facing our work of preventing imported cases as western countries reopen despite the pandemic", according to the notice.

While the regulator did not immediately respond to a Reuters request for comment, several staffers at Air China, China Southern Airlines, and Juneyao Airlines confirmed they had received such a notice.

Juneyao said it had submitted a list of employees willing to take the vaccine. The other airlines did not immediately reply to requests for comments.

It is not clear yet which candidate vaccine will be given and how many people will be vaccinated.

At least two experimental vaccines, one from Sinovac Biotech Ltd and the other from China National Biotec Group, have been approved for emergency use in China.

No vaccine has yet passed final, large-scale trials to prove it is effective enough to protect people from contracting the virus that has led to over 860,000 deaths globally.