Difficulty in Recruitment

To explore the efficacy and safety of Umbilical cord mesenchymal stem cells in the treatment of long COVID-19

Inclusion Criteria:

1. The age ranges from 18 to 85 (inclusive), regardless of gender.
2. Patients with Confirmed SARS-CoV-2 infection, according to the consensus of the Chinese diagnostic criteria for COVID-19 (Tentative tenth Edition).
3. Patients with symptoms of long COVID-19 3 months from the onset of COVID-19, lasting for at least 2 months, and the symptoms cannot be explained by other diseases.
4. Be expected to live longer than 1 year.
5. Volunteer to participate in this clinical study and sign the written informed consent.

Exclusion Criteria:

1. Those who are using immunosuppressive drugs or long-term immunosuppressive drugs after organ transplantation.
2. T lymphocyte abnormality, HIV positive.
3. Highly allergic or have a history of severe allergy.
4. Pregnant and lactating women.
5. Patients with severe autoimmune disease history;
6. Patients with uncontrolled chronic diseases or serious complications;
7. Patients with malignant tumors;
8. Patients with pulmonary embolism, acute coronary syndrome, cerebral embolism or at high risk of thromboembolism;
9. Patients with severe organ dysfunction
10. Other situations that the researchers think are not suitable for participating in this study