The corona pandemic is a continuing global challenge due to Corona Virus 2019 (COVID-19).

The purpose of the study is to confirm the accepted hypothesis from the recommendations of The European Society for Blood and Marrow Transplantation, that the vaccine for COVID-19 is safe and has good efficacy in immunocompromised patients after a bone marrow transplant from a donor / cellular therapy.

The study population will be allogeneic bone marrow transplant patients and those who have received CART therapy - immunocompromised patients who are vaccinated with COVID-19 in a commercial preparation, regardless of the study.

The following procedures are routinely performed before receiving the vaccine in the bone marrow transplant unit -

1. Blood count and lymphocyte subgroup counts before vaccination (up to 48 hours before vaccination).
2. Evaluation of GVHD activity and accompanying toxicity.
3. Receipt of a letter confirming the vaccination to the HMO.
4. One-week follow-up after vaccination including blood count, complete chemistry, GVHD evaluation, and review of adverse reactions that may be vaccine-related.
5. Referral for a second dose of the vaccine.
6. One week follow-up after vaccination including blood count, complete chemistry, GVHD evaluation, review of side effects that may be vaccine related.

The following procedures are performed only as part of the study -

1. Serology test (IgG AntiS) two weeks after the second dose of the vaccine to test the effectiveness of the vaccine.

   Cell separation two weeks after the second vaccination and execution -

2. ELISpot test to test for the release of interferon gamma in response to the stimulation of cells separated with the SARS-COV-2 virus peptides (stimulation with S peptides to evaluate vaccine response, and stimulation with M peptides as a control).

All data collected in the study will be typed into Excel and analyzed using SPSS version 25.0. Continuous data will be described using averages and standard deviations, and categorical data will be described using prevalence and percentages.

The distribution of the continuous variables will be presented using an outline graph and will be examined using the Kolmogorov Smirnov test.

An attempt will be made to perform subgroup analysis (depending on the frequency of the groups in the sample) for the patient group:

Patients after bone marrow transplantation with acute GVHD Patients after bone marrow transplantation with chronic GVHD Patients after bone marrow transplantation without immunosuppressive therapy Patients after Cell Therapy (CART) Patients lack primary immunization

Inclusion Criteria:

• Patients aged 18 and over
• Patient sex - male and female
• Bone marrow transplant from a donor (sibling or unrelated) or after cell therapy (CART) at least 3 months before vaccination.
• Patients with primary immunodeficiency syndrome.
• Patients who are able to sign an informed consent form

Exclusion Criteria:

• Patients under 18 years of age
• Patients who are unable to give informed consent
• Patients with acute GVHD who require steroid therapy above 0.5 mg / kg or who have been diagnosed in the last month.
• Patients with chronic GVHD who require steroid therapy above 0.5 mg / kg
• Patients treated with rituximab / immunoglobulins / mesenchymal cells during the last month.
• Patients whose disease is not completely cured and receive dedicated treatment for the disease.
• Patients receiving maintenance treatment for the underlying disease (excluding TKIs such as sorfenib, midostaurin, guiltritinib or cranolinib).
• Patients who have previously had COVID19.
• Patients with severe allergy to one of the vaccine components.

70 patients after allogeneic bone marrow transplant or after CART therapy and 40 patients with a primary immunodeficiency.