passed out; left arm went completely numb upon injection, numb on site; lost grip on her left side; left arm is sore all the time/left arm flares up when she's using her arm; heart rate dropped to 33 beats per minute; thought she was going to die; This spontaneous case was reported by a consumer and describes the occurrence of LOSS OF CONSCIOUSNESS (passed out) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   In January 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In February 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced LOSS OF CONSCIOUSNESS (passed out) (seriousness criterion medically significant) and HEART RATE DECREASED (heart rate dropped to 33 beats per minute). an unknown date, the patient experienced HYPOAESTHESIA (left arm went completely numb upon injection, numb on site), GRIP STRENGTH DECREASED (lost grip on her left side), PAIN IN EXTREMITY (left arm is sore all the time/left arm flares up when she's using her arm) and FEELING ABNORMAL (thought she was going to die). At the time of the report, LOSS OF CONSCIOUSNESS (passed out), GRIP STRENGTH DECREASED (lost grip on her left side), PAIN IN EXTREMITY (left arm is sore all the time/left arm flares up when she's using her arm), HEART RATE DECREASED (heart rate dropped to 33 beats per minute) and FEELING ABNORMAL (thought she was going to die) outcome was unknown and HYPOAESTHESIA (left arm went completely numb upon injection, numb on site) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Heart rate: heart rate dropped to 33 beats per minute.         Concomitant drugs were not reported.  It was reported that additional laboratory/diagnostic tests of EKG were done; however, the outcomes/results of the tests were not provided.  Treatment details were not given.  Reporter's friend had received Moderna vaccine and on behalf of her friend reporter has reported this case. The reporter stated that the first dose was the one the patient had the problem with.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.  Company Comment: This spontaneous case concerns a female patient, of unknown age, with no medical history reported, who experienced the unexpected, serious (medically significant) event of loss of consciousness and other unexpected, non-serious events. The event loss of consciousness and the non-serious event heart rate decreased occurred 1 day after receiving the first dose of the mRNA-1273 vaccine. The other non-serious events occurred unknown number of days after receiving the first dose of the mRNA-1273 vaccine. Of note, the vaccination date and event onset dates were not provided, hence, the onset latency could not be assessed. It was reported that the patient's left arm went 'completely numb upon injection, numb on site' and she lost grip on her left side. Her left arm was sore all the time and flared up when she used her arm. The patient's heart rate dropped to 33 beats per minute and she passed out. She also thought that she was going to die. An Electrocardiogram was done, however, the result was not provided. The patient was also seen by a neurologist, however, no details were provided regarding the consultation or other diagnostic test/s. Treatment information was not provided. At the time of the report, the left arm numbness had resolved while the outcomes of the other events were unknown. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a female patient, of unknown age, with no medical history reported, who experienced the unexpected, serious (medically significant) event of loss of consciousness and other unexpected, non-serious events. The event loss of consciousness and the non-serious event heart rate decreased occurred 1 day after receiving the first dose of the mRNA-1273 vaccine. The other non-serious events occurred unknown number of days after receiving the first dose of the mRNA-1273 vaccine. Of note, the vaccination date and event onset dates were not provided, hence, the onset latency could not be assessed. It was reported that the patient's left arm went 'completely numb upon injection, numb on site' and she lost grip on her left side. Her left arm was sore all the time and flared up when she used her arm. The patient's heart rate dropped to 33 beats per minute and she passed out. She also thought that she was going to die. An Electrocardiogram was done, however, the result was not provided. The patient was also seen by a neurologist, however, no details were provided regarding the consultation or other diagnostic test/s. Treatment information was not provided. At the time of the report, the left arm numbness had resolved while the outcomes of the other events were unknown. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.