Condition aggravated; First dose  more than 25 days before second dose; Seizures; Had more seizures and side effects from the vaccine/her body went into side effects; She was tired and out of it; This spontaneous case was reported by a consumer and describes the occurrence of SEIZURE (Seizures) in a 65-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 029H21B and 050E21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Seizures (Patient had minor seizures twice a month).   On 02-Oct-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Dec-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 05-Dec-2021, the patient experienced INTENTIONAL PRODUCT USE ISSUE (First dose  more than 25 days before second dose). In December 2021, the patient experienced SEIZURE (Seizures) (seriousness criterion medically significant), VACCINATION COMPLICATION (Had more seizures and side effects from the vaccine/her body went into side effects) and FATIGUE (She was tired and out of it). On an unknown date, the patient experienced CONDITION AGGRAVATED (Condition aggravated). The patient was treated with CANNABIS ongoing since an unknown date for Seizure, at an unspecified dose and frequency. On 05-Dec-2021, INTENTIONAL PRODUCT USE ISSUE (First dose  more than 25 days before second dose) had resolved. At the time of the report, SEIZURE (Seizures) and CONDITION AGGRAVATED (Condition aggravated) outcome was unknown and VACCINATION COMPLICATION (Had more seizures and side effects from the vaccine/her body went into side effects) and FATIGUE (She was tired and out of it) was resolving.            No concomitant medication was reported. She got the second shot, and then got a seizure. Then in the late afternoon, her body went into [hard to describe] side effects, which were still there. She had to go lay down. It was really scary because she never had it. Last night. 14-Dec-2021, she had a seizure. She was tired and out of it. On top of that, she also had the other side effects that she had in the afternoon. She was worried that what if she has this for the rest of her life. It was a scary feeling if not sure if it will ever go away. On 15-Dec-2021, she was feeling better. She started taking cannabis for the seizures about 2 months ago. She will up the dosage on the cannabis. She states she waited for the second one because she was having a seizure once a week, which never happened to her. Company comment: This case concerns a 65-year-old, female patient with medical history of seizures (she had minor seizures twice a month), who experienced the unexpected serious AESI of seizure and non-serious event Condition aggravated. One episode of seizures occurred 9 days after the second dose of mRNA-1273 vaccine but is it not clear when the event onset was or if she had other episodes. The rechallenge was positive, since she referred that she had seizures after the first dose for 5 weeks and that seizures reappeared after the second dose, although she also referred using cannabis which could be a potential confounder. The mentioned medical history remains as a confounder. Intentional deviation from dosage regimen was reported by the patient. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and medical judgement.   This case was linked to MOD-2021-414466 (Patient Link).; Sender's Comments: This case concerns a 65-year-old, female patient with medical history of seizures (she had minor seizures twice a month), who experienced the unexpected serious AESI of seizure and non-serious event Condition aggravated. One episode of seizures occurred 9 days after the second dose of mRNA-1273 vaccine but is it not clear when the event onset was or if she had other episodes. The rechallenge was positive, since she referred that she had seizures after the first dose for 5 weeks and that seizures reappeared after the second dose, although she also referred using cannabis which could be a potential confounder. The mentioned medical history remains as a confounder. Intentional deviation from dosage regimen was reported by the patient. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and medical judgement.