China's COVID-19 vaccine phase-two trial effective on subjects: researcher

China: The phase-two clinical trial of the COVID-19 vaccine candidate created by the Chinese Academy of Military Medical Sciences(AMMS) and Chinese biotech company CanSino Biologics has found that it is safe and can induce an immune response, according to research published in The Lancet medical journal on Monday.

The Lancet published the results of phase-one and phase-two clinical trials of a similar adenovirus vectored vaccine developed by scientists at Oxford University and biotech company AstraZeneca on Monday. That vaccine also demonstrated success in safety and potency against COVID-19.

An adenovirus vectored vaccine works by using a weakened common cold virus to introduce genetic material from the novel coronavirus into the human body. The idea is to train the body to produce antibodies that recognize the coronavirus spike protein and fight it off.

"The phase II trial was initiated on April 12 in the city of Wuhan. We've applied the methods of randomization, comparison and double-blind. The 508 participants were assigned to the placebo group and the vaccine group randomly. The purpose is to prove our vaccine's immunogenicity and safety in a larger population," said Hou Lihua, a researcher from AMMS.

Ninety-five percent of participants in the high dose group and 91 percent in the low dose group had either T-cell or antibody immune responses 28 days after receiving the vaccine. T-cells can directly target and kill invading pathogens, making them a key part of the human immune response. For the first time, the research team released the vaccine's immune effects for people over the age of 55.

"During this phase of clinic trial, we've found that the older population are having a weaker immunogenicity compared with younger population between the age of 18 to 54. But its safety level is very high. For the next step, we will further evaluate the immunizing dose and immunization schedule for older people," said Hou. CanSino, the developer of the vaccine, is in talks on launching phase-three trials in several foreign countries