China's CanSino defends coronavirus vaccine candidate after experts cast doubt

Scientists outside the company have expressed concern that the effectiveness of CanSino's candidate Ad5-nCoV, which is based on a common cold virus that many people have been exposed to, could be limited. Ad5-nCoV, still in final-stage trials, has been approved for use in the Chinese military.

China's CanSino Biologics Inc said on Wednesday expert opinion on its high-profile coronavirus vaccine candidate should not be followed "blindly" without sufficient clinical trial data. Scientists outside the company have expressed concern that the effectiveness of CanSino's candidate Ad5-nCoV, which is based on a common cold virus that many people have been exposed to, could be limited. They said existing antibodies against the common cold virus might undermine Ad5-nCoV.

"Vaccine development is a practice-based science, and we should not blindly follow experts," Zhu Tao, chief scientific officer, said during an investor conference. Ad5-nCoV, still in final-stage trials, has been approved for use in the Chinese military.