This spontaneous case was reported by a consumer and describes the occurrence of DELIRIUM (1 week to the day of booster, had sudden delirium state / was literally speaking gibberish / difficulty remembering / was unaware of what I was doing/was unaware where I was) in a 61-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 027H21B, 020B21A and 044A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below. Concurrent medical conditions included Connective tissue disorder (Mixed Connective Tissue Disorder.) since 1993. Concomitant products included ESTROGENS CONJUGATED (PREMARIN) and GABAPENTIN (NEURONTIN) for an unknown indication. On 18-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 100 microgram. On 19-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 100 microgram. On 03-Dec-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 50 microgram. In December 2021, the patient experienced DELIRIUM (1 week to the day of booster, had sudden delirium state / was literally speaking gibberish / difficulty remembering / was unaware of what I was doing/was unaware where I was) (seriousness criterion medically significant). On an unknown date, the patient experienced FEELING ABNORMAL (foggy/not clear in head), AMNESIA (have short term memory) and FATIGUE (feeling tired). The patient was treated with CLOPIDOGREL BISULFATE (PLAVIX) ongoing since an unknown date for Stroke, at an unspecified dose and frequency. In December 2021, DELIRIUM (1 week to the day of booster, had sudden delirium state / was literally speaking gibberish / difficulty remembering / was unaware of what I was doing/was unaware where I was) had resolved. At the time of the report, FEELING ABNORMAL (foggy/not clear in head), AMNESIA (have short term memory) and FATIGUE (feeling tired) had not resolved. Initially her HCP thought she had a mini stroke and prescribed Plavix, but she did not have stroke (confirmed with consumer). Patient has no allergies to (medications, food and other products). The patient had no ever COVID + test or diagnosis. Recent change in status reported as not worsening. Patient had no other vaccines given within 1 month prior to Moderna COVID-19 vaccine (type, brand, lot, route, dose #). Also, patient has not experienced a similar event in the past. COMPANY COMMENT: This spontaneous case concerns a 61-year-old, female patient with no relevant medical history, who experienced unexpected serious (seriousness criterion medically significant) event of delirium, which occurred unspecified day after third dose (reported as booster dose) of mRNA- 1273 vaccine, other non-serious events amnesia, fatigue and feeling abnormal also reported. It is reported that HCP thought that patient had mini stroke and prescribed Plavix, but she did not have stroke. The benefit-risk relationship of mRNA-1273 is not affected by this report. Sender's Comments: This spontaneous case concerns a 61-year-old, female patient with no relevant medical history, who experienced unexpected serious (seriousness criterion medically significant) event of delirium, which occurred unspecified day after third dose (reported as booster dose) of mRNA- 1273 vaccine, other non-serious events amnesia, fatigue and feeling abnormal also reported. It is reported that HCP thought that patient had mini stroke and prescribed Plavix, but she did not have stroke. The benefit-risk relationship of mRNA-1273 is not affected by this report.