(Yicai Global) Sept. 10 -- A coronavirus vaccine candidate being co-developed by CanSino Biologics and a research team with China’s Academy of Military Medical Sciences has caused no serious side effects so far, according to the firm’s chief scientist.

The adenovirus type-5 vectored Ad5-nCoV vaccine had not led to any serious adverse reactions as of Sept. 8, The Paper reported, citing Dr. Zhu Tao, who spoke at an investor forum yesterday.

Zhu’s comments came as late-stage clinical trials of an experimental coronavirus vaccine developed by AstraZeneca and Oxford University were halted yesterday after a participant fell ill. Further tests on the volunteer will be carried out before those trials can resume.

AstraZeneca’s vaccine is based on the chimpanzee virus, which the body’s immune system reacts to when it is first identified, Dr. Zhu said. The adenovirus used by CanSino is present in the human body itself, so humans are more tolerant of it.

As for the reported 9 percent adverse reaction rate for CanSino’s jab, Zhu said that it refers to very mild side effects, with only one case in Phase II clinical trials. Phase II involved 508 participants, according to previous reports.

Preserved between 2 to 8 degrees Celsius, the Ad5-nCoV vaccine can be given via intramuscular injection or through the mucous membrane and is expected to remain effective for two years, Zhu said. A single dose is as effective as two shots of inactivated vaccine. 

The vaccine, developed by CanSino and a team led by Dr. Chen Wei, a researcher at the Academy of Military Medical Sciences of the People’s Liberation Army and a member of the Chinese Academy of Engineering, has finished second phase clinical tests. Phase-III is underway in countries including Saudi Arabia and Peru.

Phase-III’s initial results are expected to be available after three to six months, the Tianjin-based company’s chief financial officer said on Sept. 1.

Editor: Peter Thomas