IgA nephropathy flare; IgA nephropathy flare; high-grade fever (Tmax of 39F) and chills; This literature-non-study case was reported in a literature article and describes the occurrence of IGA NEPHROPATHY (IgA nephropathy flare) and CONDITION AGGRAVATED (IgA nephropathy flare) in a 28-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.       No Medical History information was reported.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced IGA NEPHROPATHY (IgA nephropathy flare) (seriousness criterion medically significant), CONDITION AGGRAVATED (IgA nephropathy flare) (seriousness criterion medically significant) and PYREXIA (high-grade fever (Tmax of 39F) and chills). The patient was treated with LOSARTAN for IgA nephropathy, at a dose of 100 mg daily. At the time of the report, IGA NEPHROPATHY (IgA nephropathy flare), CONDITION AGGRAVATED (IgA nephropathy flare) and PYREXIA (high-grade fever (Tmax of 39F) and chills) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Biopsy: abnormal (abnormal) IgA nephropathy (classification  M1 E0 S1 T0 C1). On an unknown date, Body temperature: 39f (High) experienced high-grade fever (Tmax of 39F). On an unknown date, Haemoglobin urine: high (High) Workup revealed elevated hemoglobin in his urine. On an unknown date, Investigation: 1g/day Not started with steroids as urine protein excretion was below 1g/day.. On an unknown date, Physical examination: normal (normal) Physical examination did not reveal any crackles in his lungs or lower extremity edema.. On an unknown date, Proteinuria: 500 milligram per day 500mg per day and 925 milligram per day 925mg/24hr. On an unknown date, Red blood cells urine: abnormal (abnormal) 10-20 RBCs per high power field. On an unknown date, Urine analysis: 828mg/g Spot urine analysis revealed urine protein creatinine ratio of 828mg/g.. On an unknown date, White blood cells urine: negative (Negative) Workup revealed no WBCs.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered IGA NEPHROPATHY (IgA nephropathy flare), CONDITION AGGRAVATED (IgA nephropathy flare) and PYREXIA (high-grade fever (Tmax of 39F) and chills) to be possibly related.    Concomitant product use was not provided by the reporter.   Treatment information was not provided.  Patient experienced high-grade fever and chills. Next morning, he again experienced high-grade fevers and on the same night. On his visit to the clinic, patient was feeling back to normal. His vital signs were within normal limits.  Company Comment: This case concerns a 28-year-old, male patient with a history of IgA nephropathy, who experienced the unexpected serious AESI event of IgA nephropathy and the non-serious event of condition aggravated (IgA nephropathy flare), associated with non-serious event pyrexia. The event occurred at an unknown time after the second dose of Moderna COVID-19 vaccine. The rechallenge was not applicable since the events happened after the second dose and no additional dosing is expected. The medical history of IgA nephropathy and concurrent pyrexia remain as confounders. The benefit-risk relationship of Moderna COVID-19 vaccine is not affected by this report.     Reporter did not allow further contact; Sender's Comments: This case concerns a 28-year-old, male patient with a history of IgA nephropathy, who experienced the unexpected serious AESI event of IgA nephropathy and the non-serious event of condition aggravated (IgA nephropathy flare), associated with non-serious event pyrexia. The event occurred at an unknown time after the second dose of Moderna COVID-19 vaccine. The rechallenge was not applicable since the events happened after the second dose and no additional dosing is expected. The medical history of IgA nephropathy and concurrent pyrexia remain as confounders. The benefit-risk relationship of Moderna COVID-19 vaccine is not affected by this report.   Case was assessed as serious due to important medical event and medical judgement.