C3 GLOMERULONEPHRITIS; This spontaneous report was received from literature: This report concerned an 84-year-old female of an unspecified race and ethnicity. The objective of the study is to describe Mass vaccinations for coronavirus (COVID-19) are being administered worldwide. Even though vaccine is safe and effective, rare adverse events like thrombosis, thrombocytopenia, myocarditis, Guillain barre syndrome have been reported. Renal adverse events such as IgA nephropathy and minimal change disease are reported as well. A case of C3 glomerulonephritis (C3 GN) after Johnson & Johnson (J&J) vector COVID-19 vaccine. The patient's height, and weight were not reported. The patient's concurrent conditions included: diabetes, hypertension, and chronic kidney disease (Stage 3). The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin, and batch number and expiry were not reported) dose, start therapy date were not reported, 1 total administered for covid-19 prophylaxis. Age at time of vaccination 9 decade old. The batch number was not reported. Per procedure, no follow-up will be requested for this case. Concomitant medications included acetylsalicylic acid, amlodipine, carvedilol, clonidine, hydralazine, insulin and pantoprazole sodium sesquihydrate for drug used for unknown indication.  On an unspecified date (few weeks after vaccination), the patient experienced fatigue, shortness of breath, leg swelling and poor oral intake. In the emergency department, vitals were normal. She had bilateral lower extremities edema (C3 Glomerulonephritis). Laboratory data (dates unspecified) included: ANA (Antinuclear antibody) Positive, ANCA (Antineutrophil cytoplasmic antibody) Negative, Anti-dsDNA (anti-double stranded DNA) antibody Negative, Antineutrophil cytoplasmic antibody Positive, BUN (Blood urea nitrogen) (NR: not provided) 42 mg/dL, CPK (Blood creatine phosphokinase) (NR: not provided) 167 IU/L, Complement factor C3 Low, Complement factor C4 Normal, Negative, Creatinine (NR: not provided) 5.4 mg/dL, Creatinine 1.8, Hepatitis viral test Negative, Myeloperoxidase antibody test Positive, Protein urine (NR: not provided) 820 mg, Proteinase-3 antibody Negative, Renal biopsy C3 dominant glomerulonephritis with crescents and moderate interstitial fibrosis, Renal function test Worsened, SPEP (serum protein electrophoresis) Negative, Urine analysis positive for dysmorphic RBCs (Red blood cell), and Urine electrophoresis Negative. Concomitant medication Hydralazine was discontinued. With worsening renal parameters, patient was initiated on hemodialysis. Trial of Steroids and Cell Cept did not show any response and she remains on hemodialysis. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient had not recovered from c3 glomerulonephritis. The authors emphasized that, The C3 glomerulopathies are a group of rare kidney diseases characterized by complement dysregulation occurring in the glomerular microenvironment, which results in prominent complement C3 deposition. Most patients are treated with steroids in combination with either cyclophosphamide or Mycophenolate mofetil, the temporal association suggests an immune response to vaccine as a potential trigger.  This report was serious (Other Medically Important Condition). Sender's Comments: V0:  20221213115- C3 Glomerulonephritis. The event has a compatible/suggestive temporal relationship, is unlabeled, and is scientifically plausible. There is no information on any other factors potentially associated with the event. Therefore, this event is considered consistent with vaccine administration.