IgA nephropathy; Microscopic hematuria; This literature-non-study case was reported in a literature article and describes the occurrence of IGA NEPHROPATHY (IgA nephropathy) in a 19-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.       The patient's past medical history included Microscopic hematuria (Underlying disease).   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) (seriousness criterion medically significant) and HAEMATURIA (Microscopic hematuria). At the time of the report, IGA NEPHROPATHY (IgA nephropathy) outcome was unknown and HAEMATURIA (Microscopic hematuria) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood albumin: 4.5g/dl Laboratories during presentation was 4.5 g/dl. On an unknown date, Blood creatinine: 0.96mg/dl Baseline 0.96 mg/dl and 0.76g/dl Laboratories during presentation was 0.76 g/dl. On an unknown date, Protein urine: 0.61 g/d Laboratories during presentation was 0.61 g/d. On an unknown date, Red blood cells urine: 11 20 /high power field (hpf) Laboratories during presentation was 11 20/HPF.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered IGA NEPHROPATHY (IgA nephropathy) and HAEMATURIA (Microscopic hematuria) to be possibly related.    No relevant concomitant medications were reported.  Treatment was reported as conservative.  Patient was presented with Gross hematuria symptom after 2 days after second dose and it resolved in 2 days.  Duration of remission before relapse was of 6 months. Follow up time was unknown. , Blood albumin, Blood creatinine, Protein urine and Red blood cells urine lab results were unknown.  This is a regulatory case concerning a 19 year-old, male patient with clinical history of Microscopic hematuria who experienced the unexpected serious event of IgA NEPHROPATHY and other non-serious event. The events occurred unknown days after two doses of COVID-19 vaccine.  The rechallenge is unknown as per no information is available at the time of the report. The benefit-risk relationship of Spikevax is not affected by this report.   This case was linked to MOD-2021-357261, MOD-2021-357609, MOD-2021-357610, MOD-2021-357611, MOD-2021-357612, MOD-2021-357613 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 20-Oct-2021: Follow up received by safety 22-Oct-2021 included an Email and does not contain any new information; Sender's Comments: This is a regulatory case concerning a 19 year-old, male patient with clinical history of Microscopic hematuria who experienced the unexpected serious event of IgA NEPHROPATHY and other non-serious event. The events occurred unknown days after two doses of COVID-19 vaccine.  The rechallenge is unknown as per no information is available at the time of the report. The benefit-risk relationship of Spikevax is not affected by this report.