Potential side effect/ Delayed reaction/ Always has something but they do wane on and off; Hypersenstivity reaction; This spontaneous case was reported by a consumer and describes the occurrence of VACCINATION COMPLICATION (Potential side effect/ Delayed reaction/ Always has something but they do wane on and off) and HYPERSENSITIVITY (Hypersenstivity reaction) in a 23-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 076C21A, 013L20A and 013L20A) for COVID-19 vaccination.     Previously administered products included for an unreported indication: FLUARIX (Vaccine Manufacturer-GlaxoSmithKline  Body site: Left Arm Dose number: 1) on 22-Oct-2021. Concurrent medical conditions included Allergy to antibiotic (Antibiotics - type unknown Generalized rash. when patient  was a child at the time). Concomitant products included CALCIUM from 08-Nov-2021 to an unknown date, ASCORBIC ACID (VITAMINE C) from 08-Nov-2021 to an unknown date, SERTRALINE, COLECALCIFEROL (VITAMINE D3), CYANOCOBALAMIN (VITAMINE B12) and PROBIOTICS NOS for an unknown indication.   On 13-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 02-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 25-Oct-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 05-Nov-2021 at 9:00 AM, the patient experienced HYPERSENSITIVITY (Hypersenstivity reaction). On an unknown date, the patient experienced VACCINATION COMPLICATION (Potential side effect/ Delayed reaction/ Always has something but they do wane on and off). The patient was treated with METHYLPREDNISOLONE (oral) from 10-Nov-2021 to 15-Nov-2021 for Hives, at a dose of 4mg taper over 6 days; DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) (oral) ongoing from 07-Oct-2021 for Itch, at a dose of 2x night and CETIRIZINE HYDROCHLORIDE (ZYRTEC [CETIRIZINE HYDROCHLORIDE]) (oral) ongoing from 07-Oct-2021 for Rash, at a dose of 1 or 2 morning. On 15-Nov-2021, HYPERSENSITIVITY (Hypersenstivity reaction) had resolved. At the time of the report, VACCINATION COMPLICATION (Potential side effect/ Delayed reaction/ Always has something but they do wane on and off) outcome was unknown.            It was reported that on Friday 05-Nov-2021 I noticed intense itchiness on head, neck, and shoulders in the morning and it persisted on and off throughout the day. The same occurred the next morning. On Sunday 07-Nov-2021 the itch spread over the entire body along with redness and hives. Full body includes face, scalp, palms, feet, and everything else. Patient had felt no relief with Benadryl (oral and topical) nor with colloidal oatmeal treatments. Patient had went to Urgent care and was told to continue taking Benadryl. Patient was prescribed Prednisone but urged not to take it. On Monday 08-Nov-2021 the rash persisted. Patient had started taking Zyrtec in addition to Benadryl. Patient added Vitamin C and Calcium to daily medication. The rash persisted on 09-Nov-2021 again so patient returned to Urgent Care (at a different location) and was told to take Zyrtec and Pepcid in the mornings followed by Benadryl at night. Patient was also given a prescription for Methylprednisolone tapered over 6 days and instructed to take it if patient could not take the rash anymore. The doctor also recommended patient to see an allergist to get to the root of the breakout. On Wednesday 10-Nov-2021. Patient had started taking Methylprednisolone, carefully as instructed. Patient had started feeling the hives waning on Saturday 13-Nov-2021 and eventually becoming minimal on 15-Nov-2021 with a few patches on the neck in the morning.    This case was linked to MOD-2021-385740 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 12-Nov-2021: Follow-up received: Reporter's details, patient's demographics, 1st and 2nd dose details updated and event was updated. On 15-Nov-2021: Significant follow up received :- Added  medical history,event hypersensitivity, concomitant and treatment medications.