China's Sinovac coronavirus vaccine candidate appears safe, slightly weaker in elderly

Chinese firm Sinovac Biotech Ltdsaid on Monday its coronavirus vaccine candidate appeared to be safe for older people, according to preliminary results from an early to mid-stage trial, while the immune responses triggered by the vaccine were slightly weaker than younger adults.Health officials have been concerned about whether experimental vaccines could safely protect the elderly, whose immune systems usually react less robustly to vaccines, against the virus that has led to nearly 890,000 dea