Autoimmune hemolytic anemia; Off label use; This study case was reported in a literature article and describes the occurrence of AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune hemolytic anemia) in a 41-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Concurrent medical conditions included Central retinal vein occlusion and Hypertension. Concomitant products included ASPIRIN [ACETYLSALICYLIC ACID] for Central retinal vein occlusion, METOPROLOL SUCCINATE for Hypertension.    In March 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune hemolytic anemia) (seriousness criteria hospitalization prolonged, medically significant and life threatening) and OFF LABEL USE (Off label use). The patient was hospitalized on sometime in March 2021 due to AUTOIMMUNE HAEMOLYTIC ANAEMIA. The patient was treated with RITUXIMAB for Autoimmune hemolytic anemia, at a dose of 1000 milligram; RITUXIMAB for Autoimmune hemolytic anemia, at a dose of 1000 mg; PREDNISONE (oral) for Autoimmune hemolytic anemia, at a dose of 1 mg/kg once a day; IMMUNOGLOBULINS NOS (IMMUNE GLOBULIN) (intravenous) for Autoimmune hemolytic anemia, at a dose of 1 gram per kilogram and MYCOPHENOLATE MOFETIL (oral) for Autoimmune hemolytic anemia, at a dose of 1000 milligram twice a day. At the time of the report, AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune hemolytic anemia) outcome was unknown and OFF LABEL USE (Off label use) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2019, Haemoglobin (12 g/dl-16 g/dl): 7.3 g/dl (Low) 7.3 g/dL. On an unknown date, Alanine aminotransferase (7  u/l-33  u/l): 50 u/l (High) 20 days after vaccination: 50U/L, 139 u/l (High) 35 days after vaccination: 139 U/L and 41u/l (High) 77 days after vaccination: 41U/L. On an unknown date, Antinuclear antibody: weakly positive at 1:80 (Positive) ANA was weakly positive at 1:80. On an unknown date, Aspartate aminotransferase (9 u/l-32 u/l): 40 u/l (High) 20 days after vaccination: 40 U/L, 181 u/l (High) 35 days after vaccination: 181 U/L and 23 u/l (normal) 77 days after vaccination: 23 U/L. On an unknown date, Bilirubin conjugated (0-0.4 mg/dl): 0.8 mg/dl (High) 20 days after vaccination: 0.8 mg/dL and 0.6mg/dl (High) 35 days after vaccination: 0.6 mg/dl. On an unknown date, Blood albumin (3.3 g/dl-5.0 g/dl): 4 g/dl (normal) 20 days after vaccination: 4 g/dl, 4.5 g/dl (normal) 35 days after vaccination: 4.5 g/dl and 4.1 g/dl (normal) 77 days after vaccination: 4.1 g/dl. On an unknown date, Blood alkaline phosphatase (30 iu/liter-100 iu/liter): 70 iu/liter (normal) 20 days after vaccination: 70 IU/liter, 78 iu/liter (normal) 35 days after vaccination: 78 IU/liter and 63 iu/liter (normal) 77 days after vaccination: 63 IU/liter. On an unknown date, Blood bicarbonate (23 mmol/l-32 mmol/l): 26 mmol/l (normal) 20 days after vaccination: 26 mmol/l, 24 mmol/l (normal) 35 days after vaccination: 24 mmol/l and 26 mmol/l (normal) 77 days after vaccination: 26 mmol/l. On an unknown date, Blood bilirubin (0.0 mg/dl-1.0 mg/dl): 3.7 mg/dl (High) 20 days after vaccination: 3.7 mg/dL, 3.9 mg/dl (High) 35 days after vaccination: 3.9 mg/dL and 0.9 mg/dl, (normal) 77 days after vaccination: 0.9 mg/dL. On an unknown date, Blood calcium (8.5 mg/dl-10.5 mg/dl): 9 mg/dl (normal) 20 days after vaccination: 9 mg/dl, 9 mg/dl (normal) 35 days after vaccination: 9 mg/dl and 8.5 mg/dl (normal) 77 days after vaccination: 8.5 mg/dl. On an unknown date, Blood chloride (98 mmol/liter-108 mmol/liter): 105 mmol/liter (normal) 20 days after vaccination: 105 mmol/liter, 100 mmol/liter (normal) 35 days after vaccination: 100 mmol/liter and 103 mmol/liter (normal) 77 days after vaccination: 103 mmol/liter. On an unknown date, Blood creatinine (0.60 mg/dl-1.50 mg/dl): 0.70 mg/dl (normal) 20 days after vaccination: 0.70 mg/dl, 0.77 mg/dl (normal) 35 days after vaccination: 0.77 mg/dl and 0.62 mg/dl (normal) 77 days after vaccination: 0.62 mg/dl. On an unknown date, Blood glucose (70 mg/dl-100 mg/dl): 95 mg/dl (normal) 20 days after vaccination: 95 mg/dl, 150 mg/dl (High) 35 days after vaccination: 150 mg/dl and 147 mg/dl (High) 77 days after vaccination: 147 mg/dl. On an unknown date, Blood lactate dehydrogenase (100 u/liter-210 u/liter): 746 u/liter (High) 20 days after vaccination: 746 U/liter, 3095 u/liter (High) 35 days after vaccination: 3095 U/liter and 317 u/liter (High) 77 days after vaccination: 317 U/liter. On an unknown date, Blood potassium (3.4 mmol/liter-5.0 mmol/liter): 4.0 mmol/liter (normal) 20 days after vaccination: 4.0 mmol/liter, 4.1 mmol/liter (normal) 35 days after vaccination: 4.1 mmol/liter and 4.1 mmol/liter (normal) 77 days after vaccination: 4.1 mmol/liter. On an unknown date, Blood pressure measurement: 133/78 mm hg (normal) 133/78 mm Hg. On an unknown date, Blood smear test: abnormal (abnormal) A peripheral blood film revealed numerous spherocytes, reticulocytes, and nucleated RBCs.. On an unknown date, Blood sodium (135 mmol/liter-145 mmol/liter): 137 mmol/liter (normal) 20 days after vaccination: 137 mmol/liter, 137 mmol/liter (normal) 35 days after vaccination: 137 mmol/liter and 139 mmol/liter (normal) 77 days after vaccination: 139 mmol/liter. On an unknown date, Blood urea (8 mg/dl-25 mg/dl): 18 mg/dl (normal) 20 days after vaccination: 18 mg/dl, 26 mg/dl (High) 35 days after vaccination: 26 mg/dl and 15 mg/dl (normal) 77 days after vaccination: 15 mg/dl. On an unknown date, Body temperature: 96.9f (Low) 96.9F. On an unknown date, Coombs direct test: negative (Negative) The direct antiglobulin test (DAT) was negative for IgG and C3d, though an eluate prepared from the patient's red blood cells (RBCs) was reactive against all test cells., negative (Negative) Repeat DAT was again negative using routine polyspecific, IgG and C3 reagents in tube testing (Gamma-clone, Immucor, Norcross, GA). Despite the negative DAT, antibody was eluted from the patient's RBCs that demonstrated strong (3+) panreactivity when tested in the gel system. and positive (Positive) A subsequent DAT performed using gel cardsrather than Gamma-clonewas positive (2+) for IgG. Further testing demonstrated the presence of a cold autoantibody that was reactive (3+) at 37 degrees. On an unknown date, Cytomegalovirus test: negative (Negative) Negative. On an unknown date, Epstein-Barr virus test: negative (Negative) Negative. On an unknown date, Flow cytometry: did not reveal a monoclonal b cell or t-cell Flow cytometry did not reveal a monoclonal B cell or T-cell population. On an unknown date, HIV test: negative (Negative) Negative. On an unknown date, Haematocrit (36 %-46 %): 19.5% (Low) 20 days after vaccination: 19.5%, 21.9% (Low) 35 days after vaccination: 21.9% and 31.6% (Low) 77 days after vaccination: 31.6%. On an unknown date, Haemoglobin (12 g/dl-16 g/dl): 14g/dl (normal) Her baseline hemoglobin was 14 g/dL, last assessed two years prior, 7.1 g/dl (Low) 7.1 g/dL, 7.3 g/dl (Low) 7.3 g/dL, 8.0 g/dl (Low) 8.0 g/dL and 10.9 g/dl (Low) 10.9 g/dL. On an unknown date, Haptoglobin (>10 mg/dl-Unknown): <8 mg/dl (Low) 20 days after vaccination: <8 mg/dL, <10?mg/dl (Low) 35 days after vaccination: <10?mg/dL and <10 mg/dl (Low) 77 days after vaccination: <10 mg/dL. On an unknown date, Heart rate: 79 beats/min (normal) 79 beats/min. On an unknown date, Hepatitis B virus test: negative (Negative) Negative. On an unknown date, Immunology test: normal (normal) Normal limit. On an unknown date, Influenza virus test: negative (Negative) Negative. On an unknown date, Mean cell volume (80 fl-100 fl): 93 fl (normal) 20 days after vaccination: 93 fL, 109 fl (High) 35 days after vaccination: 109 fL and 103.9fl (High) 77 days after vaccination: 103.9fL. On an unknown date, Oxygen saturation: 98% (normal) oxygen saturation 98% on room air. On an unknown date, Platelet count (150000 per/µl-400000 per/µl): 204000 per/µl (normal) 20 days after vaccination: 204000 per/µl, 142000 per/µl (Low) 35 days after vaccination: 142000 per/µl and 238000 per/µl (normal) 77 days after vaccination: 238000 per/µl. On an unknown date, Protein total (6 g/dl-8.3 g/dl): 7.6 g/dl (normal) 20 days after vaccination: 7.6 g/dl, 7.5 g/dl (normal) 35 days after vaccination: 7.5 g/dl and 6.8 g/dl (normal) 77 days after vaccination: 6.8 g/dl. On an unknown date, Red cell distribution width (11.5%-14.5%): 20.7% (High) 20 days after vaccination: 20.7%, 31.5% (High) 35 days after vaccination: 31.5 and 15.9% (High) 77 days after vaccination: 15.9%. On an unknown date, Respiratory rate: 18 breaths/min (normal) 18 breaths/min. On an unknown date, Respiratory syncytial virus test: negative (Negative) Negative. On an unknown date, Reticulocyte count (0.7%-2.5%): 15.5% (High) 20 days after vaccination: 15.5%, >30% (High) 35 days after vaccination: >30% and 12.4% (High) 77 days after vaccination: 12.4%. On an unknown date, SARS-CoV-2 antibody test: negative (Negative) Testing for antibodies to the SARS-CoV-2 virus, performed 11 weeks after receipt of a single dose of the vaccine, was negative. On an unknown date, White blood cell count (4500 per/µl-13000 per/µl): 15000 per/µl (High) 20 days after vaccination: 15000 per/µl, 19000 per/µl (High) 35 days after vaccination: 19000 per/µl and 8860 per/µl (normal) 77 days after vaccination: 8860 per/µl.     mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was temporarily withheld on an unknown date.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune hemolytic anemia) and OFF LABEL USE (Off label use) to be possibly related.    Patient received her first dose of the SARS-CoV-2 mRNA-1273 vaccine in Mar-2021. Seven days after vaccination, she noted fatigue and dark urine. Twenty days after vaccination, she was admitted to another hospital. The patient continued to feel unwell, and two days following discharge from the other hospital (35 days after vaccination), she presented to another hospital with persistent fatigue and dyspnea on exertion. The patient worked as an attorney and lived with her husband and three children. She had no personal or family history of autoimmune disease. On admission to hospital, the patient was in mild distress. She was discharged home on hospital day 14 (49 days after receiving the vaccine). She was given two additional weekly doses of rituximab (1,000 mg) as an outpatient, and corticosteroids and MMF were tapered.Author informed that there was a strong clinical suspicion that the SARS-CoV-2 mRNA vaccine was the inciting event for the AIHA based on the chronology of events, the atypical autoantibody profile, and the absence of other causes. Patient's initial DAT was negative when tested with Gammaclone (Immucor) anti-IgG reagent, which does not recognize IgG4 or some types of IgG3, but positive when a reagent that detects all IgG isotypes (gel system, Ortho) was used during the elution studies. These unusual findings suggest that the warm (IgG) autoantibody consisted of an atypical subtype of either IgG4 or IgG3. Workup also revealed the presence of a cold autoantibody with a thermal amplitude of 37°C, indicating that our patient may have developed a mixed warm/cold AIHA, which comprise approximately 8% of cases of AIHA. Author concluded that patient developed a robust AIHA one week after receiving her first dose of the SARS-CoV-2 mRNA vaccine. Although causation cannot be proven, the temporal relationship in the absence of an alternative cause argues in favor of de-novo vaccine-induced AIHA.    Most recent FOLLOW-UP information incorporated above includes: On 29-Sep-2021: Follow up received by safety on 30-Sep-2021 included an Email received from team and does not contain any new information.; Sender's Comments: This case concerns a 41-year-old female patient with  no relevant medical history, who experienced the serious  unexpected event Autoimmune hemolytic anemia. The event occurred approximately 7 days after the first dose of mRNA-1273 Moderna vaccine. The rechallenge was not applicable, as a second dose of the vaccine was deferred. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.