The purpose of this study is to determine whether thymalfasin is safe and effective in patients who have sepsis

Our previous study reported that the 7-day treatment of Ta 1 demonstrated positive active effect as to the 28-day all-cause mortality and the augmentation of mHLA-DR (monocyte Human Leukocyte Antigen DR) at the secondary endpoint. Therefore, we intend to verify this finding through a randomized, double-blind and placebo-controlled clinical trial and the trail will include subjects with impaired immunologic functions.

Inclusion Criteria:

1. Age ≥ 18 and ≤85;

2. Signed informed consent signed;

3. Diagnosed as a sepsis according to the sepsis diagnosis criteria in "Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016": at least one acute severe organ dysfunction related to sepsis, and total SOFA scores ≥2;

4. Infected focus are confirmed or suspected and satisfy at least one of the followings:

   1. pathogenic microbes grow in blood or at aseptic locations

   2. presence of abscess or partially-infected tissues

   3. suspected infection identified by at least one of the following evidences:

      • leukocytes at normal aseptic locations
      • organic perforation (confirmed by imaging evidence, examination result or intestinal content leak during drainage)
      • Imaging evidence of pneumonia accompanied by purulent secretion
      • Related syndromes with high infection risk (cholangitis for example)

Exclusion Criteria:

1. History of organ or bone marrow transplantation;
2. Acute phase connective tissue diseases (such as rheumatoid diseases, systemic lupus erythematosus) and glomerulonephritis;
3. Under pregnancy or in suckling period;
4. Presence of hematologic malignancies;
5. The patient has received radiotherapy or chemotherapy within the past 30 days;
6. The patient is inclined to stop or cancel the artificial intervention for sustaining life, in other words, has abandoned treatment;
7. The patient has in the past 30 days received immunosuppressive drugs (tripterygium wilfordii, CellCept, cyclophosphamide, FK506, etc.) or received continuous treatment with prednisolone >10 mg/day (or the same dose of other hormones);
8. The patient could die of an underlying disease within 28 days or is in end-stage;
9. The patient has undergone CPR in the 72 hours before signing the informed consent and the neuromechanism has not fully recovered (GCS score ≤ 8);
10. The patient has in the past 30 days used thymosin or undergone certain clinical drug or instrument trials which could affect immunity (such as Xuebijing, ulinastatin and CRRT);
11. The patient has a medical history of allergy or intolerance to thymalfasin;
12. The source of infection cannot be contained, for example: infections that cannot be handled during surgical operations and drainage.