Experts say side effect of vaccine tolerable, dismiss pessimism
Despite skepticism and pessimism from Western media, vaccine experts advised the public not to panic over the side effects revealed in the preliminary results of a Chinese-developed coronavirus vaccine as the adverse reactions exposed are tolerable and the vaccine is under constant optimization.
The appeal came after some Western media hyped the side effect ratio reported in early-stage clinical trials of the Ad5-nCoV recombinant novel coronavirus vaccine.
The vaccine against COVID-19, jointly developed by a military research team and Chinese biopharmaceutical firm CanSino Biologics, received approval for limited military use on June 29. The vaccine candidate became the first in the world to disclose complete phase one clinical trials results and declare a dual immune response in the recipients in May.
However, around 87 percent of the 108 participants reported at least one adverse reaction within the first seven days following vaccination.
Adverse reactions are common after vaccination, and the released instances were not considered clinically significant by medical professionals. It is not powerful evidence that the vaccine failed to protect people, Tao Lina, a Shanghaibased vaccine expert, told the Global Times on Tuesday.
A CNN report in May cited US medical experts saying that the results released by Chinese research team were not a good safety sign and they recommended that the CanSino researchers to give up their efforts.
“Calling to halt the trial is unreasonable as China is showing promise of developing a successful vaccine against the coronavirus,” Tao said.
At least 19 vaccine candidates have entered clinical evaluations worldwide with seven of them from China, according to World Health Organization data updated on Monday.
The Ad5-nCoV vaccine is now under a collaborative plan to enter phase three clinical trials in Canada, and its phase two clinical trials results will be released soon, according to CanSino Biologics.
A Beijing-based immunologist who required anonymity told the Global Times on Tuesday that the vaccine needs to be improved to lower the adverse reactions, but he emphasized that it is still too early to finally determine the vaccine’s safety and efficacy as the phase two results are not yet released.