Autoimmune Hemolytic Anemia, vaccines stirred up the antibodies; Severe anemia; This spontaneous case was reported by a consumer and describes the occurrence of AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune Hemolytic Anemia, vaccines stirred up the antibodies) and ANAEMIA (Severe anemia) in a 66-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 031M20A and 004M20A) for COVID-19 vaccination.     No Medical History information was reported.   On 07-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 07-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In March 2021, the patient experienced AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune Hemolytic Anemia, vaccines stirred up the antibodies) (seriousness criterion medically significant) and ANAEMIA (Severe anemia) (seriousness criterion medically significant). The patient was treated with FOLIC ACID for Autoimmune hemolytic anemia, at an unspecified dose and frequency. At the time of the report, AUTOIMMUNE HAEMOLYTIC ANAEMIA (Autoimmune Hemolytic Anemia, vaccines stirred up the antibodies) and ANAEMIA (Severe anemia) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In March 2021, Blood test: abnormal (abnormal) Blood test revealed severe anemia..     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Two weeks after the patient's 2nd shot, a routine blood test during a physical revealed severe anemia. Currently she is being monitored by a hematologist who has diagnosed the problem as Autoimmune Hemolytic Anemia. The patient says she's getting tested every few weeks and is being treated with folic acid supplements. No transfusion or steroids were prescribed so far. The doctor thinks that one explanation for the event is that the patient might have had COVID before producing natural antibodies. With the vaccines they were stirred up leading to the autoimmune reaction.  company comment: This is a spontaneous case concerning a 56-year-old, female patient with no relevant history, who experienced the unexpected serious event of autoimmune hemolytic anemia. The event occurred approximately 2 weeks after the second dose of mRNA-1273. The patient was asymptomatic and during a routine physical exam was detected severe anemia. She was referred to a hematologist who diagnosed Autoimmune hemolytic anemia. The HCP suggests that the patient might have had COVID-19 before and the antibodies boost produced by the vaccination led to the autoimmune reaction. The patient is being tested routinely and is being treated with folic acid. No transfusion, nor steroids were required to this point. The benefit-risk relationship of mRNA-1273 in not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 22-Nov-2021: Follow-up received contains HCP information, first dose and second dose details.; Sender's Comments: This is a spontaneous case concerning a 56-year-old, female patient with no relevant history, who experienced the unexpected serious event of autoimmune hemolytic anemia. The event occurred approximately 2 weeks after the second dose of mRNA-1273. The patient was asymptomatic and during a routine physical exam was detected severe anemia. She was referred to a hematologist who diagnosed Autoimmune hemolytic anemia. The HCP suggests that the patient might have had COVID-19 before and the antibodies boost produced by the vaccination led to the autoimmune reaction. The patient is being tested routinely and is being treated with folic acid. No transfusion, nor steroids were required to this point. The benefit-risk relationship of mRNA-1273 in not affected by this report.