A COVID-19 mRNA vaccine developed by a company in east China's Shanghai was approved for clinical trials by the Center for Drug Evaluation on Monday. With volunteers for the first phase of trials now selected, the company is preparing for the manufacturing of the vaccine. Established in 2016, Stemirna Therapeutics is the first company in Shanghai to get approval for clinical trials of its experimental COVID-19 mRNA vaccine. Phase-I clinical trials are being carried out among 120 healthy volunteers to evaluate safety, tolerability and reaction. Volunteers will receive two shots with a 21-day interval.