blood sugar was 42 (very low); severe nausea; severe vomiting; abdominal pain; headache; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of BLOOD GLUCOSE DECREASED (blood sugar was 42 (very low)), NAUSEA (severe nausea), VOMITING (severe vomiting) and ABDOMINAL PAIN (abdominal pain) in a 37-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 001B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Type 1 diabetes mellitus. Concomitant products included ALUMINIUM HYDROXIDE, MAGNESIUM CARBONATE, AMPHETAMINE, DEXTROAMPHETAMINE HYDROCHLORIDE, TESTOSTERONE (ANDROGEL), APIXABAN, ACETYLSALICYLIC ACID (BABY ASPIRIN), BACLOFEN, BICTEGRAVIR SODIUM, EMTRICITABINE, TENOFOVIR ALAFENAMIDE FUMARATE (BIKTARVY), BECLOMETASONE DIPROPIONATE (BECLOMETHASONE AERONATIV), VITAMIN B12 NOS, DICLOFENAC SODIUM, DILTIAZEM, DOCUSATE SODIUM, VITAMIN D2, FERROUS GLUCONATE, FLUCONAZOLE, FUROSEMIDE, POTASSIUM CHLORIDE (LASIX + K), GLUCAGON, GABAPENTIN, HYDROCORTISONE, HYDROXYZINE, IBUPROFEN, INSULIN ASPART, EMPAGLIFLOZIN (JARDIANCE), KETOCONAZOLE, LIFITEGRAST (XIIDRA), LINACLOTIDE (LINZESS), LISINOPRIL, LORAZEPAM, MECLIZINE HCL, MORPHINE, NITROFURANTOIN (MACRODANTIN), ONDANSETRON, DOMPERIDONE, OXYCODONE, PANTOPRAZOLE, MACROGOL 3350 (MIRALAX), POTASSIUM CLAVULANATE, PROPRANOLOL HYDROCHLORIDE (PROPANOLOL BOEHRINGER), ROSUVASTATIN, SEMAGLUTIDE (OZEMPIC), SILDENAFIL CITRATE (VIAGRA CONNECT), SULFASALAZINE, INSULIN GLARGINE (TOUJEO), CARIPRAZINE HYDROCHLORIDE (VRAYLAR) and ZALEPLON (SONATA ADAMED) for an unknown indication.    On 18-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 18-Mar-2021, the patient experienced BLOOD GLUCOSE DECREASED (blood sugar was 42 (very low)) (seriousness criterion hospitalization prolonged), NAUSEA (severe nausea) (seriousness criterion hospitalization prolonged), VOMITING (severe vomiting) (seriousness criterion hospitalization prolonged), ABDOMINAL PAIN (abdominal pain) (seriousness criterion hospitalization prolonged) and HEADACHE (headache). The patient was hospitalized on 18-Mar-2021 due to ABDOMINAL PAIN, BLOOD GLUCOSE DECREASED, NAUSEA and VOMITING. At the time of the report, BLOOD GLUCOSE DECREASED (blood sugar was 42 (very low)), NAUSEA (severe nausea), VOMITING (severe vomiting), ABDOMINAL PAIN (abdominal pain) and HEADACHE (headache) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Computerised tomogram: Negative.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       Treatment information was provided as patient took two doses of emergency glucagon for low blood sugar.  In hospital the patient was treated with 3 rounds of glucagon, ondansetron hydrochloride and pain medications for the abdominal pain.; 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.