Li Zhiji, a 36-year-old volunteer, receives the recombinant novel coronavirus (COVID-19) vaccine inoculation in Wuhan, Central China's Hubei province, on March 24, 2020. The first batch of 108 volunteers arrived in Wuhan to receive inoculations after a clinical trial of the novel coronavirus vaccine in China kicked off on March 16. All recipients will be under a 14-day quarantine after vaccination. [Photo by Zhu Xingxin/chinadaily.com.cn]

China has so far approved clinical trials for three vaccines to combat the novel coronavirus, a senior official with the Ministry of Science and Technology said on Tuesday.

The first COVID-19 vaccine in the country, developed by a team led by Chen Wei, academician at the Chinese Academy of Engineering, completed the first phase of clinical trials by the end of last month and started calling up volunteers for the second phase on Thursday, according to Wu Yuanbin, director of the Ministry's bureau for social development.

"This is the first COVID-19 vaccine worldwide to go into the second phase of clinical trials," Wu said.

Over the past two days, the National Medical Products Administration has approved clinical tests for two inactivated vaccines for the novel coronavirus.

The two vaccines were developed by Wuhan Institute of Biological Products under the China National Pharmaceutical Group, and Beijing-based Sinovac Research and Development Co.

Inactivated vaccines have advantages of a relatively mature production process, controllable quality standards and wider protection range, and can be used for large-scale vaccination.

Attenuated vaccines, recombinant vaccines and nucleic acid-based vaccines are also being promoted and are expected to apply for clinical trials in April and May, Wu said. 

As for when the vaccine will be available for the public, Wu noted the fastest-developing domestic vaccines, such as adenovirus vector vaccine, have kicked off the second phase of clinical trials while waiting for the third.

"We will decide when to put the vaccine in use based on the results of clinical trials, and go through approval procedures," Wu added.