anaphylactic shock; Felt like she was going to pass out and She passed out, but she was still awake; Weakness; Sick to her stomach; Vision darkness; Could not speak/ couldn't talk; Difficulty breathing/ couldn't breathe/ couldn't get deep breaths; Body felt hot/bosy was hot/the hottest I've ever been; Felt like she was drunk; Felt like liquid was going down her arm; tingling in my hands; dizziness; felt like my airways were closing up; Nausea; This spontaneous case was reported by a consumer and describes the occurrence of ANAPHYLACTIC SHOCK (anaphylactic shock) in a 29-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 028A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 05-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 05-Apr-2021, the patient experienced ANAPHYLACTIC SHOCK (anaphylactic shock) (seriousness criterion medically significant), PRESYNCOPE (Felt like she was going to pass out and She passed out, but she was still awake), ASTHENIA (Weakness), ABDOMINAL DISCOMFORT (Sick to her stomach), VISION BLURRED (Vision darkness), SPEECH DISORDER (Could not speak/ couldn't talk), DYSPNOEA (Difficulty breathing/ couldn't breathe/ couldn't get deep breaths), FEELING HOT (Body felt hot/bosy was hot/the hottest I've ever been), FEELING DRUNK (Felt like she was drunk), FEELING ABNORMAL (Felt like liquid was going down her arm), PARAESTHESIA (tingling in my hands), DIZZINESS (dizziness), OROPHARYNGEAL DISCOMFORT (felt like my airways were closing up) and NAUSEA (Nausea). On 05-Apr-2021, PRESYNCOPE (Felt like she was going to pass out and She passed out, but she was still awake), ASTHENIA (Weakness), ABDOMINAL DISCOMFORT (Sick to her stomach), VISION BLURRED (Vision darkness), SPEECH DISORDER (Could not speak/ couldn't talk), DYSPNOEA (Difficulty breathing/ couldn't breathe/ couldn't get deep breaths), FEELING HOT (Body felt hot/bosy was hot/the hottest I've ever been), FEELING DRUNK (Felt like she was drunk) and FEELING ABNORMAL (Felt like liquid was going down her arm) had resolved. At the time of the report, ANAPHYLACTIC SHOCK (anaphylactic shock), PARAESTHESIA (tingling in my hands), DIZZINESS (dizziness), OROPHARYNGEAL DISCOMFORT (felt like my airways were closing up) and NAUSEA (Nausea) outcome was unknown.        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.   Concomitant product included birth control.   Treatment information was not provided.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded. However, Further information has been requested.   Most recent FOLLOW-UP information incorporated above includes: On 10-Sep-2021: Follow-up information received on 10 Sep 2021: Added new events and facility information.; Sender's Comments: This case concerns a 29-year-old female patient with no previous relevant medical history, who experienced the expected event of Anaphylactic shock after mRNA- 1273 vaccine (Spikevax vaccine). The event occurred hours after the first dose of Spikevax. The rechallenge was not applicable since only information about one dose was disclosed. The event is consistent with the current understanding of the mechanism of action of the study medication. The benefit-risk relationship of Spikevax is not affected by this report. Clarification regarding confirmation of the diagnosis and information regarding treatment received has been requested.