passed out/unconscious for approximately 20 minutes; This spontaneous case was reported by a consumer and describes the occurrence of LOSS OF CONSCIOUSNESS (passed out/unconscious for approximately 20 minutes) in a 49-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 027H21B, 002C21A and 026B21A) for COVID-19 vaccination.     No medical history was provided by the reporter.  Concomitant products included ESCITALOPRAM OXALATE (LEXAPRO) for an unknown indication.   On 07-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 05-May-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 01-Dec-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 03-Dec-2021, after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced LOSS OF CONSCIOUSNESS (passed out/unconscious for approximately 20 minutes) (seriousness criterion medically significant). On 03-Dec-2021, LOSS OF CONSCIOUSNESS (passed out/unconscious for approximately 20 minutes) had resolved.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   The patient stated that on 03-Dec-2021, he was out having lunch and passed out. He stated he was uncoscious for approximately 20 minutes. An ambulance was called, and he was taken to the emergency room. The patient had a series of tests performed while in the hospital and all the test results came back normal.  He was discharged approximately 5 hours later with no treatment medications. No hospitalization required. The caller stated he was discharged and he mentioned the E.R. doctor did not know what caused him to pass out. The patient had no history of passing out.  No treatment information was provided.  Company comment: This case concerns a 49-year-old male patient with no medical history, who experienced the serious unexpected event of Loss of consciousness which occurred two days following the administration of the booster dose of the mRNA-1273 vaccine. Reportedly, the patient suddenly passed out and was unconscious for approximately 20 minutes. The patient was taken to the emergency room and had a series of unspecified tests, but all the test results came back normal. The patient recovered and was discharged approximately 5 hours later with no treatment medications. The reason for the reported event remained unknown. The re-challenge is not applicable as the event occurred following the third (booster) dose. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This case concerns a 49-year-old male patient with no medical history, who experienced the serious unexpected event of Loss of consciousness which occurred two days following the administration of the booster dose of the mRNA-1273 vaccine. Reportedly, the patient suddenly passed out and was unconscious for approximately 20 minutes. The patient was taken to the emergency room and had a series of unspecified tests, but all the test results came back normal. The patient recovered and was discharged approximately 5 hours later with no treatment medications. The reason for the reported event remained unknown. The re-challenge is not applicable as the event occurred following the third (booster) dose. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.