This spontaneous case was reported by a patient and describes the occurrence of LOSS OF CONSCIOUSNESS (she also passed out the same night after receiving this vaccine/she also passed out the same night after receiving this vaccine/she states the symptoms lasted about an hour and then after she vomited, they subsisted) in a 65-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 00CM21A and 026D21A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below. Previously administered products included for Drug use for unknown indication: Johnson & Johnson (Dose-1 and Lot number-202A21A) on 11-Apr-2021. Past adverse reactions to the above products included No adverse event with Johnson & Johnson. On 26-Oct-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 09-Apr-2022, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 09-Apr-2022, the patient experienced LOSS OF CONSCIOUSNESS (she also passed out the same night after receiving this vaccine/she also passed out the same night after receiving this vaccine/she states the symptoms lasted about an hour and then after she vomited, they subsisted) (seriousness criterion medically significant), VOMITING (Felt like vomiting/she states the symptoms lasted about an hour and then after she vomited, they subsisted) and CHILLS (Chills ). In April 2022, LOSS OF CONSCIOUSNESS (she also passed out the same night after receiving this vaccine/she also passed out the same night after receiving this vaccine/she states the symptoms lasted about an hour and then after she vomited, they subsisted) and CHILLS (Chills) had resolved. At the time of the report, VOMITING (Felt like vomiting/she states the symptoms lasted about an hour and then after she vomited, they subsisted) outcome was unknown. For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments. Patient had no allergies. No relevant concomitant medications were reported. As per report patient had never tested positive for Covid-19. No treatment medication reported. Company comment: This spontaneous case concerns a 65 year old female patient without a reported medical history who experienced the unexpected, serious (medically significant) event of Loss of consciousness which occurred the same night after receiving the dose of mRNA1273 as third dose of COVID-19 vaccine. It should also be noted that the patient received the a dose of COVID-19 vaccine from a different manufacturer (Johnson and Johnson) 11 months 29 days prior to the latest dose of mRNA1273 (interchange of vaccine products) and did not result in any adverse reaction. The patient started having chills and felt like vomiting a few hours post vaccination. She was also reported to have passed out the same night after vaccination. The patient states that the symptoms lasted for about an hour and after vomiting the condition subsided. Further details regarding the clinical course and treatment were not provided. The benefit-risk relationship of mRNA-1273 is not affected by this report. Sender's Comments: This spontaneous case concerns a 65 year old female patient without a reported medical history who experienced the unexpected, serious (medically significant) event of Loss of consciousness which occurred the same night after receiving the dose of mRNA1273 as third dose of COVID-19 vaccine. It should also be noted that the patient received the a dose of COVID-19 vaccine from a different manufacturer (Johnson and Johnson) 11 months 29 days prior to the latest dose of mRNA1273 (interchange of vaccine products) and did not result in any adverse reaction. The patient started having chills and felt like vomiting a few hours post vaccination. She was also reported to have passed out the same night after vaccination. The patient states that the symptoms lasted for about an hour and after vomiting the condition subsided. Further details regarding the clinical course and treatment were not provided. The benefit-risk relationship of mRNA-1273 is not affected by this report.