could barely walk from bedroom to kitchen; hives; difficulty breathing; extreme dizziness; pruritus; rash; nausea; chest tightness; This spontaneous case was reported by an other health care professional and describes the occurrence of CHEST DISCOMFORT (chest tightness), DYSPNOEA (difficulty breathing), PRURITUS (pruritus), RASH (rash) and NAUSEA (nausea) in a 25-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 26L20A) for COVID-19 vaccination.     Concurrent medical conditions included Asthma, Psoriatic arthritis since 2014, Celiac disease since 2016, Colitis since 2018, Throat infection (Cobblestone throat) since 2004, Psoriasis, Allergic reaction to antibiotics (omnicef) since 01-Oct-2005, Hay fever and Allergic reaction to antibiotics (vancomycin-hives) since 08-Oct-2014. Concomitant products included SALBUTAMOL (ALBUTEROL HFA) for Asthma, CLOBETASOL PROPIONATE for Psoriasis.   On 30-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 02-Jan-2021, the patient experienced CHEST DISCOMFORT (chest tightness), RASH (rash) and NAUSEA (nausea). On 05-Jan-2021, the patient experienced DYSPNOEA (difficulty breathing) and PRURITUS (pruritus). The patient was treated with DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) (intravascular) 07-Jan-2021 for Antihistamine therapy, at a dose of 50 mg; DEXAMETHASONE (DECADRON [DEXAMETHASONE]) (intravascular) 07-Jan-2021 for Steroid therapy, at a dose of 10 mg; PREDNISOLONE (oral) from 07-Jan-2021 to 15-Jan-2021 at a dose of 5 mg twice a day and MECLIZINE HCL (oral) from 07-Jan-2021 to 12-Jan-2021 at a dose of 25 mg twice a day. On 15-Jan-2021, CHEST DISCOMFORT (chest tightness), DYSPNOEA (difficulty breathing), PRURITUS (pruritus), RASH (rash) and NAUSEA (nausea) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 07-Jan-2021, Blood pressure measurement: 157 mmHg (High) 112. On 07-Jan-2021, Body temperature: 99.7 (High) 99.7. On 07-Jan-2021, Heart rate: 136 (High) 136. On 07-Jan-2021, Respiratory rate: 18 (normal) 18. On 26-Jan-2021, Tryptase: 4.3mcg/l (Inconclusive) reference range :less than 11.0mcg/l.   mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was withdrawn on an unknown date.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   On 07-Jan-2021, the patient was seen in the emergency room and hives worsened and developed shortness of breath. All of patient's symptoms have subsided by 17-Jan-2021. The dizziness is the only symptom that had lasted that long. All other symptoms had improved after the IV Benadryl (diphenhydramine) and decadron (dexamethasone), in addition to the prednisone.   Most recent FOLLOW-UP information incorporated above includes: On 28-Jun-2021: Events updated.; Sender's Comments: This case concerns a 25 year old female who developed nonserious unexpected event of dizziness approximately 5 days after first dose of mRNA-1273.  She developed nonserious unlisted events of hives, heart rate increased, and unsteady gate a few days later. She was seen on the ER and treated with IV Benadryl and IV Decadron. Outcome of the events was not provided at the time of this report. Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded.