Chinese academician Chen Wei’s team unveils first-phase clinical result of COVID19 vaccine

The first clinical trial of a # COVID19 vaccine developed by the Chinese research team of academician Chen Wei announced the latest successful result on May 22, which has attracted worldwide attention on China’s fast-track vaccine.

The Ad5 vectored COVID-19 vaccine was approved to go into clinical trial after it passed the clinical research registration review on March 16. Since then, 108 volunteers have received a shot in the first phase of the trial and 508 volunteers had started the second phase of the trial by April 25.

Wang Junzhi, an academician of the Chinese Academy of Engineering, said at a State Council press conference on April 14 that there will be a third phase and based on the results, scientists will decide whether the vaccine is safe for mass usage.

Wang said the third phase will involve an even bigger sample of hundreds of people and it will require a longer time to observe how the vaccine protects the population from the virus.

Chen’s team was the first to publish the results of a phase-one clinical trial in the world. The results were positive, as most subjects induced rapid T-cell responses. On the 28th day after vaccination, most of the subjects had developed cellular responses or virus-neutralizing antibodies.

However, at the same time, Professor Zhu Fengcai, deputy director of the Jiangsu Provincial Center for Disease Control and Prevention, and a co-author of the paper on The Lancet, said the pre-existing immunity of Ad5 may slow the rapid immune response to SARS-CoV-2 and reduce the peak response.

In addition, high levels of Ad5 pre-existing immunity may also have a negative impact on the durability of the vaccine-induced immune response.

“The challenge of developing a COVID-19 vaccine is unprecedented, and the ability to induce an immune response does not necessarily indicate that the vaccine can completely protect humans from SARS-CoV-2 infection. We still have a lot of work to do before it enters the market,” Chen said.