Application and Research of Mesenchymal Stem Cells in Alleviating Severe Development of COVID-19 Infection

This study is to evaluate the safety and efficacy of umbilical cord mesenchymal stem cells Therapy for COVID-19.

Inclusion Criteria:Age 18-85 years;The diagnosis of COVID-19 infection was clinically classified as Moderate cases, and the criteria were based on Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 10)Having the relevant clinical manifestations of COVID-19 infection.Having one or more of the following etiological and serological examination resultsTested positive for Novel Coronavirus nucleic acidTested positive for Novel Coronavirus antigenNovel Coronavirus was isolated and cultured positiveNovel Coronavirus specific immunoglobulin G reaches a titration of at least 4-fold increase during convalescence compared with the acute phase.Moderate cases diagnostic criteria：Persistent high fever > 3 days or (and) cough, Tachypnea etc，but respiratory rate≧30 breaths/ min ,oxygen saturation > 93% on finger pulse oximeter taken at rest. Radiology shows the characteristic manifestations of COVID-19 pneumoniaThere are one or more of the following risk factors for the development of severe / critical severity:Patients over 65 years old, especially those who have not been vaccinated against novel coronavirusPatients with cardiovascular and cerebrovascular diseases (including hypertension), chronic lung disease, diabetes, chronic liver and kidney disease, tumors and other underlying diseases, as well as maintenance dialysisPatients with immune deficiency (such as AIDS, long-term use of corticosteroids or other immunosuppressive drugs resulting in immune dysfunction)Patients with Obesity (body mass index ≥30)late trimester of pregnancy and perinatal womenHeavy smoker.Exclusion Criteria:Patients with prior or present tumor history,or precancerous lesions confirmed by pathological examination.Patients with active acute myocardial infarction or acute cerebral infarction.Pregnant or lactating patients.Patients with poorly controlled mental illness.Patients addicted to alcohol or drugs.Patients Unable or unwilling to sign informed consent or poor compliance.Patients with active tuberculosis or influenza virus, adenovirus and other acute respiratory virus infection.Patients deemed unsuitable for stem cell therapy by clinicians.Patients enrolled in other clinical trials within 3 months.