The first clinical trial of the novel coronavirus vaccine in China has begun, and photos and videos of volunteers taking part in the project began to circulate on social media over the weekend.

The phase 1 clinical trial for recombinant novel coronavirus vaccine was registered on March 17, according to the Chinese Clinical Trial Registry. The COVID-19 vaccine was jointly developed by the Institute of Biotechnology, the Academy of Military Medical Sciences of the People's Liberation Army and Tianjin-based CanSino Biologics Inc.

The trial is being conducted on 108 healthy adults ages of 18 to 60 in two medical facilities in the former epicenter of the virus, Wuhan, Hubei province. The trial is expected to be completed by Dec 31, according to the registry.

It is thought to be the first China-made novel coronavirus vaccine being tested on humans. As a subunit vaccine, it contains only a fragment of the pathogen to stimulate a protective immune response.

Scientists around the world have raced to develop a vaccine, with trials already underway or about to start in China, the United States and Europe.

On March 15, scientists at Kaiser Permanente Washington Health Research Institute began the first vaccine trial in the US. In the United Kingdom, researchers at Oxford University will begin testing their vaccine on animals next week and hope to begin human trials by April.

The Chinese team, led by senior bioengineer Major General Chen Wei, has worked almost around the clock since late January to develop a vaccine candidate with sound scientific data, said Yu Xuefeng, chairman and CEO of CanSino Biologics Inc.

This vaccine candidate is built on the company's technology that was successfully applied to develop the vaccine against Ebola virus infection. Results from preclinical animal studies show that the vaccine candidate can induce a strong immune response. Preclinical animal safety studies demonstrated a good safety profile, Yu said.

On Saturday, Ren Chao, a volunteer from Wuhan, posted a video clip showing him being injected with the vaccine candidate on Friday on the Chinese video-sharing platform Douyin. "It's all worth it if my participation can help people not having to wear masks and seeing each other's smile," he wrote in the post.

Ren said he heard volunteers were needed for the clinical trial of the vaccine on March 17 and underwent full medical examinations the next day. "It's something that I'm proud of. Of course, I feel a little bit nervous about the trial, but I trust the scientists," he said on Sunday.

On Thursday, a female volunteer posted two photos of her being injected with the vaccine candidate on China's Twitter-like social media platform Sina Weibo. "I want to do something out of the ordinary, and I'm prepared to face the possible complications," Science and Technology Daily newspaper quoted her as saying on Saturday.

The volunteers will receive a series of follow-up examinations in the six months after being injected to see if their bodies have generated an antibody to the virus, according to the registry.