A health worker shows a dose of the Chinese vaccine Sinopharm Covid-19 in a vaccination center in the Jordanian capital Amman on January 13, 2021.

Khalil Mazraawi | AFP | Getty Images

BEIJING – Sinopharm, a state-owned giant in coronavirus vaccine development in China, announced that its chairman resigned from the board on Tuesday.

The company cited personal reasons for Li Zhiming’s resignation, according to a release made for the Hong Kong-listed company. Li Hui, a member of the board of directors and the audit committee of Sinopharm subsidiary China National Medicines Corp., also resigned Tuesday for personal reasons.

In late December, Chinese authorities approved a vaccine being developed for general launch by a Beijing-based subsidiary of Sinopharm. According to state media, the vaccine had a 79.34% effectiveness after a Phase 3 test.

In early December, the United Arab Emirates said the vaccine was 86% effective.

There was no direct indication that the resignation was due to vaccination work. The company did not immediately respond to CNBC’s email request for comment.

Different countries have published different results on the effectiveness of a coronavirus vaccine from another Chinese company, Sinovac.

A WHO team is working with manufacturers of Covid-19 vaccines from Chinese pharmaceutical companies Sinovac and Sinopharm “to assess compliance with international quality manufacturing practices prior to a possible emergency listing by the WHO,” said WHO Director General Tedros Adhanom Ghebreyesus earlier this week.