Acute renal failure; his feet and ankles are very swollen like he was retaining fluid; cellulitis behind his right knee; dizziness; looked like hives; rash had spread all over his body; fever; pretty sick; rash around the injection site; This spontaneous case was reported by a consumer and describes the occurrence of ACUTE KIDNEY INJURY (Acute renal failure) and CELLULITIS (cellulitis behind his right knee) in a 54-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 040C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 21-Jul-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 21-Jul-2021, the patient experienced VACCINATION SITE RASH (rash around the injection site). On 23-Jul-2021, the patient experienced ILLNESS (pretty sick). On 24-Jul-2021, the patient experienced DIZZINESS (dizziness), URTICARIA (looked like hives), RASH (rash had spread all over his body) and PYREXIA (fever). On 26-Jul-2021, the patient experienced ACUTE KIDNEY INJURY (Acute renal failure) (seriousness criteria hospitalization and medically significant). On 29-Jul-2021, the patient experienced CELLULITIS (cellulitis behind his right knee) (seriousness criterion medically significant). On 08-Aug-2021, the patient experienced PERIPHERAL SWELLING (his feet and ankles are very swollen like he was retaining fluid). The patient was hospitalized from 25-Jul-2021 to 28-Jul-2021 due to ACUTE KIDNEY INJURY. The patient was treated with DOXYCYCLINE for Cellulitis, at an unspecified dose and frequency; DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) (intravenous) at an unspecified dose and frequency and NAPROXEN for Fever, at an unspecified dose and frequency. At the time of the report, ACUTE KIDNEY INJURY (Acute renal failure), CELLULITIS (cellulitis behind his right knee), ILLNESS (pretty sick), DIZZINESS (dizziness), URTICARIA (looked like hives), PERIPHERAL SWELLING (his feet and ankles are very swollen like he was retaining fluid), VACCINATION SITE RASH (rash around the injection site), RASH (rash had spread all over his body) and PYREXIA (fever) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 26-Jul-2021, Blood pressure measurement: 88 over 55 (abnormal) blood pressure was 88 over 55.         Concomitant medications were not reported by reporter.  Patient received first dose of Covid-19 vaccine on 23rd June 2021 (LOT#: 015C21A Exp date: Unknown)  Patient went to emergency room on Sunday where he did blood work and chest X-ray.  Patient was given steroids through IV as a treatment for the adverse events. Patient was in hospital until Wednesday and was receiving IV hydration and blood work to monitor his daily progress.  Company comment: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.  Based on the mechanism of action of mRNA-1273, a causal association between the event of  Right Knee Cellulitis and mRNA-1273 is assessed as unlikely related. Very limited information regarding the event of Acute Kidney Injury has been provided at this time, further information has been requested.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.  Based on the mechanism of action of mRNA-1273, a causal association between the event of  Right Knee Cellulitis and mRNA-1273 is assessed as unlikely related. Very limited information regarding the event of Acute Kidney Injury has been provided at this time, further information has been requested.