The defence from Sinovac Chief Executive Officer Yin Weidong at a press briefing in Beijing on Jan 13 followed growing confusion as trials conducted in Brazil, Indonesia and Turkey released four different efficacy rates for the same vaccine.
Chinese vaccine developer Sinovac Biotech Ltd. said that the low efficacy rate of 50.38% from its final-stage trial in Brazil is due to trial participants being medical workers facing a high risk of contracting Covid-19.
In contrast, western vaccines like that developed by Pfizer Inc. and BioNTech SE were tested among volunteers including people from the general population, some of whom were less exposed to the virus in their daily lives compared to medical workers.
