BEIJING — Sinopharm, a state-owned giant in China's coronavirus vaccine development, announced its chairman left the board Tuesday. The company cited personal reasons for Li Zhiming's resignation, according to a filing for the Hong Kong-listed company. Li Hui, a director and audit committee member of Sinopharm subsidiary China National Medicines Corp. also resigned Tuesday due to personal reasons, a separate filing disclosed. In late December, Chinese authorities approved a vaccine developed by a Beijing-based subsidiary of Sinopharm for general launch. The company said the vaccine had efficacy of 79.34% after a phase three test, according to state media. Earlier in December, the United Arab Emirates said the vaccine was 86% effective. There was no direct indication the resignations came as a result of vaccine-related work.