Staff members work in a laboratory in Wuhan, central China's Hubei Province, Feb. 13, 2020. (Xinhua/Xiong Qi)

According to clinical results, 12 to 24 hours after the patients received the treatment, they have shown improved clinical symptoms.

BEIJING, Feb. 14 (Xinhua) -- China has developed convalescent plasma to treat patients who are infected with the novel coronavirus (COVID-19), according to the China National Biotec Group.

The company said they have collected plasma from some recovered patients to prepare therapeutic products including convalescent plasma and immune globulin.

After strict blood biosafety tests, virus inactivation and antiviral activity tests, they have successfully developed convalescent plasma for clinical treatment and have used it to treat critically ill patients.

The company has set up a team to use special equipment to collect plasma from recovered patients in Wuhan since Jan. 20.

Three critically ill patients in a hospital in the Jiangxia District of Wuhan received convalescent plasma treatment on Feb. 8. Currently, more than 10 critically ill patients have received the treatment, according to the company.

According to clinical results, 12 to 24 hours after the patients received the treatment, they have shown improved clinical symptoms, with main inflammatory indexes decreased significantly and some key indexes such as blood oxygen saturation improving comprehensively.