The vaccine, developed by CanSino Biological Inc. and the Beijing Institute of Biotechnology, was tested in 108 healthy, uninfected adults aged 18 to 60 in Wuhan, China — the original ground zero of the pandemic.
All the participants received injections at low, middle or high doses, and no “serious” side effects were reported, researchers said.
Almost half of vaccine recipients reported fever, with 44% reporting fatigue and 39% reporting a headache. Overall, 9% of patients reported side effects that were severe enough to have potentially “prevented activity.”
These side effects are “not a good safety sign,” said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia.
Experts also suggested the vaccine did not elicit a strong immune response; all the doses, even the “low” dose, were actually very high, Offit said.