felt like was going to  pass out five times/two times blackout; develop a pretty large swollen in the side of the chest; a rash that expand from the chest  to their neck; This spontaneous case was reported by a consumer and describes the occurrence of LOSS OF CONSCIOUSNESS (felt like was going to  pass out five times/two times blackout) in a 34-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 028k21a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 29-Dec-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 29-Dec-2021, the patient experienced SWELLING (develop a pretty large swollen in the side of the chest) and RASH (a rash that expand from the chest  to their neck). On 31-Dec-2021, the patient experienced LOSS OF CONSCIOUSNESS (felt like was going to  pass out five times/two times blackout) (seriousness criterion medically significant). At the time of the report, LOSS OF CONSCIOUSNESS (felt like was going to  pass out five times/two times blackout) outcome was unknown and SWELLING (develop a pretty large swollen in the side of the chest) and RASH (a rash that expand from the chest  to their neck) had not resolved.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       No concomitant medication reported. No treatment information was provided.  The patient received the first dose of the Moderna COVID-19 vaccine on the 29Dec2021 (lot number 028k21a) and developed a pretty large swelling in the side of the chest and a rash that expand from the chest to the neck. Also on 31Dec2021, the patient felt like she was going to pass out five times and two times blackout. The report stated that the rash was still getting worst and the swelling from the chest was getting bigger and could be seen visually. The patient wanted to know what to do.  Company Comment: This spontaneous case concerns a 34-year-old, female patient with no medical history reported, who experienced the unexpected, serious event of loss of consciousness and other associated unexpected and expected, non-serious events. The non-serious events occurred on the same day after administration of the first dose of the Moderna mRNA-1273 vaccine. The event loss of consciousness occurred 2 days after administration of the first dose of the Moderna mRNA-1273 vaccine. Treatment information was not provided. The non-serious events had not resolved at the time of the report. The outcome of the event loss of consciousness was unknown at the time of the report. The rechallenge was not applicable as the events occurred after the first dose. The benefit-risk relationship of the Moderna mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a 34-year-old, female patient with no medical history reported, who experienced the unexpected, serious event of loss of consciousness and other associated unexpected and expected, non-serious events. The non-serious events occurred on the same day after administration of the first dose of the Moderna mRNA-1273 vaccine. The event loss of consciousness occurred 2 days after administration of the first dose of the Moderna mRNA-1273 vaccine. Treatment information was not provided. The non-serious events had not resolved at the time of the report. The outcome of the event loss of consciousness was unknown at the time of the report. The rechallenge was not applicable as the events occurred after the first dose. The benefit-risk relationship of the Moderna mRNA-1273 vaccine is not affected by this report.