China’s Vaccine Front-Runner Aims to Beat Covid the Old-Fashioned Way

Many of the 200-plus Covid-19 vaccine projects under way around the world are focused on new technologies—inoculations based on messenger RNA, for example, or genetically modified cold viruses. The company developing one of China’s leading vaccine candidates, by contrast, is betting that humanity’s best chance may lie with a shot not too different from the kind that’s been in use for hundreds of years.

Beijing-based Sinovac Biotech Ltd., a company with a strong medical track record but a turbulent corporate history, began final-stage trials in July on CoronaVac. It relies on an inactive version of the novel coronavirus to teach human immune systems to recognize and destroy the real thing. In terms of timing, the company was ahead of most other potential vaccines, including the new models meant to facilitate strong protection and fast production. Sinovac’s candidate has a good chance of entering commercial production almost as quickly as Moderna Inc.’s mRNA vaccine, or the genetically modified shot being developed by the University of Oxford and AstraZeneca Plc.