passed out at home; not able to sleep; had no appetite; feeling lightheaded; temperature of 100°F; very tired; This spontaneous case was reported by a patient and describes the occurrence of LOSS OF CONSCIOUSNESS (passed out at home) in a 78-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 011a214 and 007m20a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Fruit allergy (avocados), Iodine contrast media allergy, Sulfonamide allergy (sulfa), Penicillin allergy and Cancer (taking prednisone diagnosis for Cancer was received before receiving the 1st dose of the Moderna COVID19 vaccine). Concomitant products included PREDNISONE for Cancer, ATORVASTATIN CALCIUM (STATIN [ATORVASTATIN CALCIUM]) for an unknown indication.   On 03-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 08-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In 2021, the patient experienced LOSS OF CONSCIOUSNESS (passed out at home) (seriousness criterion medically significant), INSOMNIA (not able to sleep), DECREASED APPETITE (had no appetite), DIZZINESS (feeling lightheaded), PYREXIA (temperature of 100°F) and FATIGUE (very tired). In 2021, LOSS OF CONSCIOUSNESS (passed out at home), INSOMNIA (not able to sleep), DECREASED APPETITE (had no appetite), DIZZINESS (feeling lightheaded), PYREXIA (temperature of 100°F) and FATIGUE (very tired) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Body temperature: 100°F.         It was reported that patient had the same symptoms and it went on for a month.  Treatment information was not provided.  Company comment: This spontaneous case concerns a 78-year-old male patient, with relevant medical history of cancer, who experienced the unexpected serious (medically significant) event of Loss of consciousness that occurred after receiving the second dose of mRNA-1273 vaccine in COVID-19 vaccination series. Latency could not be assessed as the exact date of onset of the event was not available. Patient had also received first (approximately 33 days prior to second dose), third and fourth dose of Moderna vaccine. It was reported that patient experienced similar events after receiving fourth dose. No further information on risk factors, additional medical history (site, type and stage of cancer), clinical course, investigations and treatment received were provided. The outcome of the event was recovered. Patients' medical history of cancer remains as a confounder for loss of consciousness. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-661329 (Patient Link).; Sender's Comments: This spontaneous case concerns a 78-year-old male patient, with relevant medical history of cancer, who experienced the unexpected serious (medically significant) event of Loss of consciousness that occurred after receiving the second dose of mRNA-1273 vaccine in COVID-19 vaccination series. Latency could not be assessed as the exact date of onset of the event was not available. Patient had also received first (approximately 33 days prior to second dose), third and fourth dose of Moderna vaccine. It was reported that patient experienced similar events after receiving fourth dose. No further information on risk factors, additional medical history (site, type and stage of cancer), clinical course, investigations and treatment received were provided. The outcome of the event was recovered. Patients' medical history of cancer remains as a confounder for loss of consciousness. The benefit-risk relationship of mRNA-1273 is not affected by this report.