The southern Chinese city of Shenzhen has started rolling out free coronavirus vaccines for workers and students looking to travel overseas.

Five community health centers in Shenzhen have been designated as vaccination centers for the free service for locals. The city has so far vaccinated around 140,000 people involved at-risk environments such as cold chain logistics or frontline epidemic control.

Officials say the inoculations will expand to other members of the public once vaccines receive approval for general use and there's sufficient supply. In one community health facility in Nanshan District, around 400 applicants made appointments on the first day registration was available. 

"I was working in a company in Japan before the pandemic. The situation still isn't good in Japan, so receiving this vaccine will allow me to feel a lot safer. I think China has the best control over the virus globally, so I'm confident about the vaccine that I'm taking," said a vaccine recipient.

Although the inoculation only takes a few seconds to complete, recipients must stay in an observation room for 30 minutes after getting jabbed. They then must wait for another 14 to 28 days for the second shot in order to complete the vaccination.

"I am going to continue my studies in Britain. I've waited here for 15 minutes and I don't feel anything irregular. I feel a lot safer after the inoculation, but no matter what, I will still keep myself indoors and take preventive measures when I get to the UK," said another vaccine recipient.

A number of countries have been rushing to develop safe vaccines, as the pandemic has claimed 1.7 million lives worldwide. But medics say only those fit to receive an injection should consider taking a COVID-19 vaccine. In the U.S., one American medical worker who fainted after receiving the Moderna vaccine later revealed she had a history of allergies.

China now has 15 vaccine candidates in clinical trials, with five of them in Phase 3 trials; there has been few complications so far, say the companies. 

"We are using the vaccine developed by Sinovac, and we have thousands of vials in storage. Vaccination against COVID-19 just started, but the number of those getting inoculated in Shenzhen alone has reached 140,000. We have witnessed cases of mild allergic reactions and have handled them well. But serious adverse reactions, such as shock and organ damage, have not been reported," said Song Shuyi, director of the Dachong Community Health Service Center.

Medics say it generally takes a month for the vaccine to take effect, and it can remain active for a year if the virus doesn't mutate. They also stressed those who have received the vaccine should still take preventive measures to avoid infection.

All the photos were provided by CGTN's Li Huishan