fatigue; lost a lot of weight; having problems with their heart; seizures; migraine; 3rd dose: 19Aug2021 1st booster: 21Oct2021 024C21A; This spontaneous case was reported by a patient and describes the occurrence of SEIZURE (seizures), MIGRAINE (migraine), FATIGUE (fatigue), WEIGHT DECREASED (lost a lot of weight) and CARDIAC DISORDER (having problems with their heart) in a 73-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 024C21A, 043L20A and 025L20A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy (codeine) and Rheumatoid arthritis.   On 09-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 19-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 21-Oct-2021, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In May 2022, received fifth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In 2021, the patient experienced MIGRAINE (migraine) (seriousness criterion hospitalization). On an unknown date, the patient experienced SEIZURE (seizures) (seriousness criteria hospitalization and medically significant), FATIGUE (fatigue) (seriousness criterion hospitalization), WEIGHT DECREASED (lost a lot of weight) (seriousness criterion hospitalization), CARDIAC DISORDER (having problems with their heart) (seriousness criterion hospitalization) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (3rd dose: 19Aug2021 1st booster: 21Oct2021 024C21A). The patient was treated with LEVETIRACETAM (KEPPRA [LEVETIRACETAM]) at an unspecified dose and frequency and OXYCODONE HYDROCHLORIDE (OXYCONTIN) at an unspecified dose and frequency. At the time of the report, SEIZURE (seizures), MIGRAINE (migraine) and FATIGUE (fatigue) had not resolved and WEIGHT DECREASED (lost a lot of weight), CARDIAC DISORDER (having problems with their heart) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (3rd dose: 19Aug2021 1st booster: 21Oct2021 024C21A) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Magnetic resonance imaging: Lungs are clear and brain had an MRI which were clear.. On an unknown date, Weight: went from 185 to 132 pounds.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered SEIZURE (seizures), MIGRAINE (migraine), FATIGUE (fatigue), WEIGHT DECREASED (lost a lot of weight) and CARDIAC DISORDER (having problems with their heart) to be related. No further causality assessment was provided for INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (3rd dose: 19Aug2021 1st booster: 21Oct2021 024C21A).    No concomitant medications were reported. Patient believed their side effects were related to the booster. Patient had been seizures without warning, lost a lot of weight. Patient had extreme migraine and was being treated for migraines. After booster in 2022, patient ended up in ICU in Aug2022 and had been extremely sick. Patient woke in the ICU in Dec2022 and Jan2022. Patient just got out of the ICU about 5 days ago. Patient had problems with her heart and had a lot of fatigue. Patient was battling a terrible headache all the time. Patient was extremely fatigued and had blank spots from their last seizures. Patient started to have migraines after the third dose, but the last dose kicked patient's butt. HCP was going to start patient on some injections next week. The symptom of migraine was reported as headache.  Company comment: This is a spontaneous case regarding a 73-year-old female patient, with concurrent medical condition of rheumatoid arthritis, who received 5 doses of mRNA-1273 vaccine and experienced unexpected and serious (hospitalization and medically significant) event of seizure (AESI) and unexpected and serious (hospitalization) events of migraine, fatigue, weight loss and cardiac disorder. According to the report, patient started having migraines after the third dose but the last dose made it worse. She experienced seizures since getting the booster dose and has been in the ICU three times. First hospitalization occurred 3 months after receiving the fifth dose. Second and third hospitalization occurred 7 months an 8 months after receiving fifth dose, respectively. Patient also lost a lot of weight, had unspecified problems with her heart and experienced a lot of fatigue. She stated that brain MRI  was normal and lungs were clear. HCP prescribed Keppra and Oxycontin and a treatment with unspecified injections was going to start next week. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.