* participation in any other clinical trial of an experimental agent treatment * active gvhd or history of gvhd * history of car-t-cell therapy * covid-19 who ordinal scale ≥6 * anticipated life-expectancy \<72 hours * expected duration of hospital stay \<72 hours * sepsis-induced leukopenia or thrombocytopenia (leukocytes \<1,000/µl or platelets \<50,000/µl). if the cytopenias result from underlying hematologic disease or its treatment this will not be regarded as exclusion criterion * ct pneumonia score ≥13 \[50\] * any steroids ≥1 mg/kg prednisolon-equivalent/kg bw, besides 6 mg dexamethasone i.v. or p.o. 1x/d as soc for covid-19 * pregnant or breast feeding * any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study * therapeutic donor lymphocyte infusion (dli) less than 100 days prior to imp infusion * known hypersensitivity to iron dextran * known pre-existing human anti-mouse antibodies (hamas) * ontraindication against mandatory protocol-inherent comedication(s): antihistamine and/or acetaminophen * failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: * oral hormonal contraception ('pill') * dermal hormonal contraception * vaginal hormonal contraception (nuvaring®) * contraceptive plaster * long-acting injectable contraceptives * implants that release progesterone (implanon®) * tubal ligation (female sterilization) * intrauterine devices that release hormones (hormone spiral) * double barrier methods * this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). * persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator * legally incapacitated persons * persons held in an institution by legal or official order

* participation in any other clinical trial of an experimental agent treatment * active gvhd or history of gvhd * history of car-t-cell therapy * covid-19 who ordinal scale ≥6 * anticipated life-expectancy \<72 hours * expected duration of hospital stay \<72 hours * sepsis-induced leukopenia or thrombocytopenia (leukocytes \<1,000/µl or platelets \<50,000/µl). if the cytopenias result from underlying hematologic disease or its treatment this will not be regarded as exclusion criterion * ct pneumonia score ≥13 \[50\] * any steroids ≥1 mg/kg prednisolon-equivalent/kg bw, besides 6 mg dexamethasone i.v. or p.o. 1x/d as soc for covid-19 * pregnant or breast feeding * any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study * therapeutic donor lymphocyte infusion (dli) less than 100 days prior to imp infusion * known hypersensitivity to iron dextran * known pre-existing human anti-mouse antibodies (hamas) * ontraindication against mandatory protocol-inherent comedication(s): antihistamine and/or acetaminophen * failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: * oral hormonal contraception ('pill') * dermal hormonal contraception * vaginal hormonal contraception (nuvaring®) * contraceptive plaster * long-acting injectable contraceptives * implants that release progesterone (implanon®) * tubal ligation (female sterilization) * intrauterine devices that release hormones (hormone spiral) * double barrier methods * this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). * persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator * legally incapacitated persons * persons held in an institution by legal or official order

participation in any other clinical trial of an experimental agent treatment active gvhd or history of gvhd history of car-t-cell therapy covid-19 who ordinal scale ≥6 anticipated life-expectancy <72 hours expected duration of hospital stay <72 hours sepsis-induced leukopenia or thrombocytopenia (leukocytes <1,000/µl or platelets <50,000/µl). if the cytopenias result from underlying hematologic disease or its treatment this will not be regarded as exclusion criterion ct pneumonia score ≥13 [50] any steroids ≥1 mg/kg prednisolon-equivalent/kg bw, besides 6 mg dexamethasone i.v. or p.o. 1x/d as soc for covid-19 pregnant or breast feeding any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study therapeutic donor lymphocyte infusion (dli) less than 100 days prior to imp infusion known hypersensitivity to iron dextran known pre-existing human anti-mouse antibodies (hamas) ontraindication against mandatory protocol-inherent comedication(s): antihistamine and/or acetaminophen failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: oral hormonal contraception ('pill') dermal hormonal contraception vaginal hormonal contraception (nuvaring®) contraceptive plaster long-acting injectable contraceptives implants that release progesterone (implanon®) tubal ligation (female sterilization) intrauterine devices that release hormones (hormone spiral) double barrier methods this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator legally incapacitated persons persons held in an institution by legal or official order

participation in any other clinical trial of an experimental agent treatment active gvhd or history of gvhd history of car-t-cell therapy covid-19 who ordinal scale ≥6 anticipated life-expectancy <72 hours expected duration of hospital stay <72 hours sepsis-induced leukopenia or thrombocytopenia (leukocytes <1,000/µl or platelets <50,000/µl). if the cytopenias result from underlying hematologic disease or its treatment this will not be regarded as exclusion criterion ct pneumonia score ≥13 [50] any steroids ≥1 mg/kg prednisolon-equivalent/kg bw, besides 6 mg dexamethasone i.v. or p.o. 1x/d as soc for covid-19 pregnant or breast feeding any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study therapeutic donor lymphocyte infusion (dli) less than 100 days prior to imp infusion known hypersensitivity to iron dextran known pre-existing human anti-mouse antibodies (hamas) ontraindication against mandatory protocol-inherent comedication(s): antihistamine and/or acetaminophen failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: oral hormonal contraception ('pill') dermal hormonal contraception vaginal hormonal contraception (nuvaring®) contraceptive plaster long-acting injectable contraceptives implants that release progesterone (implanon®) tubal ligation (female sterilization) intrauterine devices that release hormones (hormone spiral) double barrier methods this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator legally incapacitated persons persons held in an institution by legal or official order

- participation in any other clinical trial of an experimental agent treatment for covid-19 - covid-19 who ordinal scale ≥6 - anticipated life-expectancy <72 hours - expected duration of hospital stay <72 hours - leukocytes <1000/µl or platelets <50.000/µl unless resulting from underlying disease or it's treatment - ct pneumonia score ≥13 [50] - any other steroids ≥ 1mg/kg prednisolone-equivalent/kg bw, besides 6mg dexamethasone i.v. or p.o. 1x/d (standard of care) - pregnant or breast feeding - any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study - failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: - oral hormonal contraception ('pill') - dermal hormonal contraception - vaginal hormonal contraception (nuvaring®) - contraceptive plaster - long-acting injectable contraceptives - implants that release progesterone (implanon®) - tubal ligation (female sterilization) - intrauterine devices that release hormones (hormone spiral) - double barrier methods this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). - persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator - legally incapacitated persons - persons held in an institution by legal or official order [not yet final]

- participation in any other clinical trial of an experimental agent treatment for covid-19 - covid-19 who ordinal scale ≥6 - anticipated life-expectancy <72 hours - expected duration of hospital stay <72 hours - leukocytes <1000/µl or platelets <50.000/µl unless resulting from underlying disease or it's treatment - ct pneumonia score ≥13 [50] - any other steroids ≥ 1mg/kg prednisolone-equivalent/kg bw, besides 6mg dexamethasone i.v. or p.o. 1x/d (standard of care) - pregnant or breast feeding - any serious medical condition or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the subject's safe participation in and completion of the study - failure to use highly-effective contraceptive methods. the following contraceptive methods with a pearl index lower than 1% are regarded as highly-effective: - oral hormonal contraception ('pill') - dermal hormonal contraception - vaginal hormonal contraception (nuvaring®) - contraceptive plaster - long-acting injectable contraceptives - implants that release progesterone (implanon®) - tubal ligation (female sterilization) - intrauterine devices that release hormones (hormone spiral) - double barrier methods this means that the following are not regarded as safe: condom plus spermicide, simple barrier methods (vaginal pessaries, condom, female condoms), copper spirals, the rhythm method, basal temperature method, and the withdrawal method (coitus interruptus). - persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator - legally incapacitated persons - persons held in an institution by legal or official order [not yet final]