Change in epilepsy semiology; This literature-non-study case was reported in a literature article and describes the occurrence of EPILEPSY (Change in epilepsy semiology) in a 23-year-old male patient who received SPIKEVAX NOS (SPIKEVAX NOS) for COVID-19 prophylaxis.   The patient's past medical history included Trauma (Patient has a history of non-accidental trauma at the age of 1 and developed epilepsy.). Concurrent medical conditions included Epilepsy. Concomitant products included OXCARBAZEPINE for Seizure prophylaxis.    In February 2021, the patient received second dose of SPIKEVAX NOS (SPIKEVAX NOS) (unknown route) 1 dosage form. On 04-Mar-2021,  after starting SPIKEVAX NOS (SPIKEVAX NOS), the patient experienced EPILEPSY (Change in epilepsy semiology) (seriousness criteria hospitalization and medically significant). The patient was treated with TOPIRAMATE (TOPIRAMATE EXTENDED RELEASE) at a dose of 125 milligram once a day and TOPIRAMATE (TOPIRAMATE EXTENDED RELEASE) at a dose of 150 milligram once a day. In May 2021, EPILEPSY (Change in epilepsy semiology) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Electroencephalogram: patient previous work-up included routine EEG's that demonstrated abundant left occipital interictal discharges and rare left temporal epileptiform discharges and captured two seizures of this described semiology with generalized onset and a third seizure with left hemispheric onset. On an unknown date, Magnetic resonance imaging head: showed ventricular enlargement due to diffuse parenchymal loss as well as signal abnormality in the bilateral occipital lobes.     For SPIKEVAX NOS (SPIKEVAX NOS) (Unknown), the reporter considered EPILEPSY (Change in epilepsy semiology) to be related.    Patient typical seizures were described as nystagmus towards the left followed by loss of awareness and behavioral arrest. These seizures occurred 2-4 times a month. Based on the data and described semiology, it was felt that the patient had seizures arising from the occipital region. On March 4, 2021, one week after receiving the second dose of the Moderna COVID19 vaccination, the patient started having a new seizure semiology that consisted of brief gaze deviation to the left followed by forced gaze deviation to the right with associated right head version. This then progressed to a bilateral upper extremity tonic seizure and then a bilateral asymmetric tonic seizure. Patient was evaluated in the Epilepsy Monitoring Unit. Patient was discharged with Topiramate ER and remained seizure free at his follow-up appointment 2 months later.   Author concluded that the Moderna COVID 19 vaccination may temporarily change the seizure semiology of epilepsy patients. Although the exact mechanism is unclear, it appears that in this case there was propagation of an alternative pathway in the epileptogenic network. More data is needed for our post-vaccination patients with epilepsy.  Company Comment: This is a literature non-study case concerning a 23-year-old, male patient with relevant medical history of epilepsy, who experienced the serious (due to medically significant) unexpected, AESI of Epilepsy, reported as "Change in epilepsy semiology after COVID 19 vaccine administration".  The event occurred one week after the second dose of SPIKEVAX COVID-19 VACCINE NOS. The patient has a history of non-accidental trauma at the age of 1 and developed epilepsy. His typical seizures were described as having nystagmus towards the left followed by loss of awareness and behavioral arrest, 2-4 times a month. Based on the semiology, EEG and MRI findings, it was felt that the patient was having seizures arising from the occipital region. His anti-seizure medication regimen included Oxcarbazepine 600mg daily and Topiramate ER 125 mg daily. One week after receiving the second dose of the Moderna COVID19 vaccination, the patient started having a new seizure semiology that consisted of brief gaze deviation to the left followed by forced gaze deviation to the right with associated right head version. This then progressed to a bilateral upper extremity tonic seizure and then a bilateral asymmetric tonic seizure. He was evaluated in the Epilepsy Monitoring Unit and the EEG captured two seizures of this described semiology with generalized onset and a third seizure with left hemispheric onset. He was discharged with Topiramate ER 150 mg daily and remained seizure free at his follow-up appointment 2 months later. The outcome of the event was reported as resolved. The authors stated that although the exact mechanism is unclear, it appears that in this case there was propagation of an alternative pathway in the epileptogenic network. The mentioned medical history remains as a confounder. The benefit-risk relationship of SPIKEVAX COVID-19 VACCINE NOS vaccine is not affected by this report.