seizures or seizure like activity; chest pains; hypotension; Severe lethargy; Dysphagia; This spontaneous case was reported by an other health care professional and describes the occurrence of SEIZURE (seizures or seizure like activity) in a 94-year-old female patient who received mRNA-1273.815 (SPIKEVAX 2023-2024) (batch no. 8058877) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Unspecified protein-calorie malnutrition, Osteoarthritis, Generalised muscle weakness, Difficulty in walking (DIFFICULTY IN WALKING, NOT ELSEWHERE CLASSIFIED), Cognitive disorder (COGNITIVE COMMUNICATION DEFICIT), Mobility decreased, Anxiety disorder, Hyperlipidemia, Essential hypertension, Atherosclerosis of renal artery, Gastroesophageal reflux disease (GASTRO-ESOPHAGEAL REFLUX DISEASE WITHOUT ESOPHAGITIS), Allergic rhinitis, Pain in joint involving lower leg, Acute cerebellar ataxia, Fracture due to osteoporosis (AGE-RELATED OSTEOPOROSIS WITH CURRENT PATHOLOGICAL FRACTURE, RIGHT FEMUR), Insomnia NOS, Constipation, Occlusion carotid, Osteoporosis (AGE-RELATED OSTEOPOROSIS WITHOUT CURRENT PATHOLOGICAL FRACTURE), COVID-19, Anemia, unspecified, Vitamin D deficiency and Behavior disorder (UNSPECIFIED SEVERITY, WITH OTHER BEHAVIORAL DISTURBANCE). Previously administered products included for Product used for unknown indication: Pfizer Bivalent (Dose 5 Lot no - GH9703 Expiry date - 10/21/22) on 22-Sep-2022. Past adverse reactions to the above products included No adverse event with Pfizer Bivalent. Concurrent medical conditions included Oropharyngeal dysphagia (DYSPHAGIA, OROPHARYNGEAL PHASE), Hypothyroidism, Primary hyperparathyroidism, Fracture due to osteoporosis (OTHER INTERVERTEBRAL DISC DEGENERATION, LUMBAR REGION), Dementia, Sulfonamide allergy (Sulfa) and Agitation. Concomitant products included LORAZEPAM (ATIVAN) for Agitation, BUSPIRONE HYDROCHLORIDE for Anxiety, MIRTAZAPINE (REMERON) for Appetite fluctuation, BENAZEPRIL HYDROCHLORIDE (LOTENSIN [BENAZEPRIL HYDROCHLORIDE]) for Hypertension, MULTIPLE VITAMINS WITH MINERALS for Nutritional support, TRAMADOL HYDROCHLORIDE (TRAMADOL HCL A) for Pain, CALCIUM CARBONATE, COLECALCIFEROL (CALCIUM CARBONATE AND VITAMIN D) and ONDANSETRON HYDROCHLORIDE (ZOFRAN [ONDANSETRON HYDROCHLORIDE]) for an unknown indication.    On 11-Jun-2023, the patient received sixth dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (Intramuscular use) 1 dosage form. On 11-Aug-2023, the patient experienced HYPOTENSION (hypotension), LETHARGY (Severe lethargy) and DYSPHAGIA (Dysphagia). On an unknown date, the patient experienced SEIZURE (seizures or seizure like activity) (seriousness criterion medically significant) and CHEST PAIN (chest pains). At the time of the report, SEIZURE (seizures or seizure like activity) and CHEST PAIN (chest pains) outcome was unknown and HYPOTENSION (hypotension), LETHARGY (Severe lethargy) and DYSPHAGIA (Dysphagia) had not resolved.        The action taken with mRNA-1273.815 (SPIKEVAX 2023-2024) (Intramuscular use) was unknown.   For mRNA-1273.815 (SPIKEVAX 2023-2024) (Intramuscular use), the reporter did not provide any causality assessments.   This case refers to patient 5 out of 9 patients reported.   Patient had dose 1 on 02-Mar-2021, dose 2 on 03-Apr-2021, dose 3 on 28-Oct-2021 lot 012F21A (Expiry date: 13-Nov-2021) on 06-Oct-2022 and dose 4 on 27-Jun-2022 Lot 017B22A (Expiry date: 27-Jul-2022).   It was reported that 9 patients who had adverse events after getting the Spikevax vaccine had common adverse events - chest pains, hypo or hypertension and seizures or seizures like activity.  Treatment medication was not reported.   This case was linked to US-MODERNATX, INC.-MOD-2023-749140 (E2B Linked Report).  Company Comment: This is a spontaneous case concerning a 94-year-old female patient with relevant medical history of Unspecified protein-calorie malnutrition, Osteoarthritis, Generalised muscle weakness, Difficulty in walking, Cognitive disorder, Mobility decreased, Anxiety disorder, Hyperlipidemia, Essential hypertension, Atherosclerosis of renal artery, Gastroesophageal reflux disease, Acute cerebellar ataxia, Insomnia NOS, Occlusion carotid, Anemia, unspecified, Vitamin D deficiency and Behavior disorder,  among others, and concurrent  Oropharyngeal dysphagia, Hypothyroidism, Primary hyperparathyroidism, Dementia among others, who experienced the serious (due to medically significant) unexpected, AESI of Seizures, among other non-serious events. The event Seizure occurred on an unknown date after a dose of mRNA-1273.815 vaccine, received as the sixth dose of COVID-19 vaccination schedule, and the rest of the events Chest pain, Hypotension, Lethargy and Dysphagia occurred on the same day after the vaccine administration. It was reported that the patient presented hypotension, severe lethargy and dysphagia, he received supportive treatment, BP improved, he was still lethargic and continued with dysphagia. Clinical course, additional supportive diagnostic procedures, and treatment were not provided. The patient's advanced age and mentioned medical history and multiple concurrent comorbidities remains as confounders. The benefit-risk relationship of mRNA-1273.815 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 10-Nov-2023: Live significant follow-up received. Lot number updated. Reference number added. On 10-Nov-2023: Live follow-up received with significant information with vaccine details. On 10-Nov-2023: Live follow-up received with significant information. On 13-Nov-2023: Live follow-up received by safety on 14-Nov-2023 included: reference numbers and narrative was updated. On 13-Nov-2023: Live Significant follow up added. Reporter was added. Patient age group added.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-749140:Master case