Kangzhong (Beijing) Biotechnology Co., Ltd.

(1) Preliminarily determine the positive judgment criteria for D-EC to provide a basis for determining the final positive judgment criteria for Phase III clinical studies; (2) Determine the dose used in Phase III clinical studies; (3) Evaluate the safety and dose of D-EC in clinical use, and the correlation between the incidence of adverse reactions and D-EC.

The purpose of the trial is to evaluate the safety and tolerability of recombinant Mycobacterium tuberculosis fusion protein (D-EC) for human studies

Primary study objectives: (1) To evaluate the safety and tolerability of skin test Mycobacterium tuberculosis antigen (D-EC) in human studies; (2) To evaluate the correlation between the incidence of adverse reactions to the clinical dose of D-EC and D-EC. Secondary study objectives: (1) To evaluate the correlation between D-EC and three test reagents, TB-PPD and IGRA, in subjects with normal chest imaging and pulmonary tuberculosis aged 66 to 75 years; (2) To evaluate the correlation between D-EC and two test reagents, IGRA, in healthy subjects aged 3 to 17 years and patients with respiratory diseases including tuberculosis;