they saw brain activity much more on EEG; She had no electrolytes in her body; she was throwing up; she stopped breathing; her heart stopped; she was sick all day; She started having seizures at hospital; she got sick; She threw up; threw her back out; This spontaneous case was reported by a patient family member or friend and describes the occurrence of RESPIRATORY ARREST (she stopped breathing), SEIZURE (She started having seizures at hospital), CARDIAC ARREST (her heart stopped), ELECTROENCEPHALOGRAM NORMAL (they saw brain activity much more on EEG), ILLNESS (she got sick), VOMITING (She threw up), BACK PAIN (threw her back out), ILLNESS (she was sick all day), VOMITING (she was throwing up) and ELECTROLYTE DEPLETION (She had no electrolytes in her body) in a 34-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. Unknown) for COVID-19 vaccination.     No Medical History information was reported.    On 27-Aug-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-Sep-2021, the patient experienced ILLNESS (she got sick) (seriousness criterion life threatening), VOMITING (She threw up) (seriousness criterion life threatening) and BACK PAIN (threw her back out) (seriousness criterion life threatening). In September 2021, the patient experienced SEIZURE (She started having seizures at hospital) (seriousness criteria hospitalization, medically significant and life threatening). On 21-Sep-2021, the patient experienced ILLNESS (she was sick all day) (seriousness criteria hospitalization and life threatening). On 21-Sep-2021 at 11:30 PM, the patient experienced RESPIRATORY ARREST (she stopped breathing) (seriousness criteria hospitalization, medically significant and life threatening), CARDIAC ARREST (her heart stopped) (seriousness criteria hospitalization, medically significant and life threatening) and VOMITING (she was throwing up) (seriousness criteria hospitalization and life threatening). On an unknown date, the patient experienced ELECTROENCEPHALOGRAM NORMAL (they saw brain activity much more on EEG) (seriousness criteria hospitalization and life threatening) and ELECTROLYTE DEPLETION (She had no electrolytes in her body) (seriousness criteria hospitalization and life threatening). The patient was hospitalized on 22-Sep-2021 due to CARDIAC ARREST, ILLNESS, RESPIRATORY ARREST and VOMITING. The patient was treated with FENTANYL at an unspecified dose and frequency; OXYCODONE at an unspecified dose and frequency; LEVETIRACETAM (KEPPRA XR) at an unspecified dose and frequency; LACOSAMIDE (VIMPAT) at an unspecified dose and frequency; Manual therapy (CPR started , EMR shocked her with pads,At hospital, placed her in induced coma and did a cooling) for Respiratory arrest; Manual therapy (CPR started, EMR shocked her with pads,At hospital, placed her in induced coma and did a cooling) for Cardiac arrest and Manual therapy (At hospital, they placed her in induced coma and did a cooling) for Vomiting. At the time of the report, RESPIRATORY ARREST (she stopped breathing), SEIZURE (She started having seizures at hospital), CARDIAC ARREST (her heart stopped), ELECTROENCEPHALOGRAM NORMAL (they saw brain activity much more on EEG), ILLNESS (she got sick), VOMITING (She threw up), BACK PAIN (threw her back out), ILLNESS (she was sick all day), VOMITING (she was throwing up) and ELECTROLYTE DEPLETION (She had no electrolytes in her body) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Electroencephalogram: abnormal (abnormal) saw brain activity much more on EEG. On 22-Sep-2021, Blood electrolytes: decreased (abnormal) no electrolytes in her body.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   No Concomitant medication provided. The patient had (unspecified) Hearth and Blood pressure treatment medication.  Company Comment: This case concerns a 34 year old female with no reported medical history , who experienced Serious, unexpected events of Illness, Vomiting and Back pain which occurred 14 days after vaccination with the 1st dose of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine ) . After 25 days after vaccination with the 1st dose she experienced serious unexpected events of Illness , Vomiting , respiratory arrest and Cardiac arrest  . On the 26th day post vaccination with the 1st dose she had Seiziures and Electrolyte depletion .  On an unkown date patient experienced  EEG normal (they saw brain activity much more on EEG increased activity   .  The re-challenge for this case is not applicable since the outcome of the events are unknown. The benefit-risk relationship of mRNA-1273 (Moderna Covid 19 Vaccine ) is not affected by this report.; Sender's Comments: This case concerns a 34 year old female with no reported medical history , who experienced Serious, unexpected events of Illness, Vomiting and Back pain which occurred 14 days after vaccination with the 1st dose of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine ) . After 25 days after vaccination with the 1st dose she experienced serious unexpected events of Illness , Vomiting , respiratory arrest and Cardiac arrest  . On the 26th day post vaccination with the 1st dose she had Seiziures and Electrolyte depletion .  On an unkown date patient experienced  EEG normal (they saw brain activity much more on EEG increased activity   .  The re-challenge for this case is not applicable since the outcome of the events are unknown. The benefit-risk relationship of mRNA-1273 (Moderna Covid 19 Vaccine ) is not affected by this report.