The present invention provides methods for preventing, treating, or reducing the severity of sepsis, severe sepsis or septic shock, including bacterial, viral, and fungal infections, and including infections of more complex etiology. The invention involves the administration of an alpha thymosin peptide regimen. In certain embodiments, the alpha thymosin peptide regimen is scheduled or timed with respect to potential, expected and/or diagnosed sepsis, severe sepsis or septic shock. In certain embodiments, the patient is immunodeficient or immunocompromised, and/or the patient is hospitalized or scheduled for hospitalization, such that the regimen of alpha thymosin peptide helps to protect the patient from, or reduce the severity of, sepsis, severe sepsis or septic shock.
