Brown out and Fainted / turned yellow and blue; sweating profusely; nauseous; Interchange of vaccine products; This spontaneous case was reported by a consumer and describes the occurrence of SYNCOPE (Brown out and Fainted / turned yellow and blue) in a 31-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 060H21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Previously administered products included for COVID-19 vaccination: Johnson and Johnson vaccine on 11-Apr-2021. Past adverse reactions to the above products included No adverse event with Johnson and Johnson vaccine.    On 19-Dec-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 19-Dec-2021, the patient experienced SYNCOPE (Brown out and Fainted / turned yellow and blue) (seriousness criterion medically significant), HYPERHIDROSIS (sweating profusely), NAUSEA (nauseous) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). The patient was treated with EPINEPHRINE for Adverse event, at an unspecified dose and frequency. On 19-Dec-2021, SYNCOPE (Brown out and Fainted / turned yellow and blue), HYPERHIDROSIS (sweating profusely), NAUSEA (nauseous) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) had resolved.            No concomitant product use was provided by the reporter. The patient had received a primary vaccine series of the Johnson and Johnson vaccine on 11APR2021 (lot number 203A21A).   Within 1-2 minutes period after he got the booster dose he started sweating profusely, got nauseous and started to get a brown out like how before to faint. At 10-12 minutes after the shot he fainted. The vaccination providers said he had turned yellow and blue. He was administered epinephrine, and his vitals stabilized shortly after. He went home and hydrated. He was feeling ok now, and had not experienced that since.   Company comment: This spontaneous case concerns a 31-year-old male patient with no medical history reported, who experienced the unexpected serious (medically significant) event of Syncope after mRNA- 1273 Moderna vaccine, booster dose of the vaccination schedule. Interchange of vaccine products was captured since the patient received initial schedule of vaccination with Johnson and Johnson vaccine. Syncope occurred approximately 10-12 minutes after the booster dose of mRNA- 1273 vaccine. Hyperhidrosis and Nausea were experienced immediately after vaccination as prodromes. Very limited information is available at this moment regarding medical assessment of the event. Treatment with Adrenaline was administered and the patient recovered. Vasovagal syncope can occur after vaccination. However, since the patient was given adrenaline, the event might have been assessed as an allergic reaction / anaphylaxis. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a 31-year-old male patient with no medical history reported, who experienced the unexpected serious (medically significant) event of Syncope after mRNA- 1273 Moderna vaccine, booster dose of the vaccination schedule. Interchange of vaccine products was captured since the patient received initial schedule of vaccination with Johnson and Johnson vaccine. Syncope occurred approximately 10-12 minutes after the booster dose of mRNA- 1273 vaccine. Hyperhidrosis and Nausea were experienced immediately after vaccination as prodromes. Very limited information is available at this moment regarding medical assessment of the event. Treatment with Adrenaline was administered and the patient recovered. Vasovagal syncope can occur after vaccination. However, since the patient was given adrenaline, the event might have been assessed as an allergic reaction / anaphylaxis. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.