Since december 2019, acute respiratory disease due to 2019 novel coronavirus (2019-nCoV) emerged in Wuhan city and rapidly spread throughout China. There is no confirmed antivirus therapy for 2019-nCoV infection. Natural killer (NK) cells are innate lymphocytes that may serve as useful effectors against danger infection. The purpose of this clinical investigation is to evaluate the safety and efficiency of NK Cells in combination with standard therapy for pneumonia patients infected with 2019-nCoV.

Inclusion Criteria:

• 1. Male or female, aged at 18 years-65 years old
• 2. Pneumonia that is judged by chest radiograph or computed tomography
• 3. Laboratory confirmation of NCP infection by reverse-transcription polymerase chain reaction(RT-PCR) from any diagnostic sampling source

Exclusion Criteria:

• 1. Pregnancy or breastfeeding
• 2. Known HIV, HBV or HCV infection
• 3. Patients with malignant tumor, other serious systemic diseases and psychosis
• 4. Patients who are participating in other clinical trials
• 5. Inability to provide informed consent or to comply with test requirements