Couldn't walk straight/off balance spells. Spent 4 weeks lying down most of the time; Something is swollen; Inflammed; Vertigo; Felt like had a temperature; horrible headaches / headaches come and go; Headaches Like a migraine; Lots of pressure on her head/Headache feels like head is on lots of pressure,; Heart racing; Lost balance/off balance spells. Spent 4 weeks lying down most of the time; Dizzy spell for about 3x / dizzy; myalgia; vaccination site pain; 79-day gap of both doses; Feels a little warm; This spontaneous case was reported by a consumer and describes the occurrence of BALANCE DISORDER (Lost balance/off balance spells. Spent 4 weeks lying down most of the time), DIZZINESS (Dizzy spell for about 3x / dizzy), HEAD DISCOMFORT (Lots of pressure on her head/Headache feels like head is on lots of pressure,), PALPITATIONS (Heart racing) and FEELING HOT (Feels a little warm) in a 76-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 00621A and 007M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Migraine, Allergy to plants (trees and shrubs(no medication taken for this)) and Kidney disorder. Concomitant products included ELETRIPTAN HYDROBROMIDE (RELPAX) for Migraine, LEVOTHYROXINE SODIUM (LEVOTHYROXIN) for Thyroid disorder, ESTROGENS CONJUGATED (PREMARIN) for an unknown indication.   On 16-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 07-May-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 12-May-2011,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced FEELING HOT (Feels a little warm). On 16-Feb-2021, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (79-day gap of both doses). On 07-May-2021, the patient experienced BALANCE DISORDER (Lost balance/off balance spells. Spent 4 weeks lying down most of the time), DIZZINESS (Dizzy spell for about 3x / dizzy), PALPITATIONS (Heart racing), MYALGIA (myalgia) and VACCINATION SITE PAIN (vaccination site pain). On 08-May-2021, the patient experienced HEAD DISCOMFORT (Lots of pressure on her head/Headache feels like head is on lots of pressure,), MIGRAINE (Headaches Like a migraine), PYREXIA (Felt like had a temperature) and HEADACHE (horrible headaches / headaches come and go). On an unknown date, the patient experienced GAIT DISTURBANCE (Couldn't walk straight/off balance spells. Spent 4 weeks lying down most of the time), SWELLING (Something is swollen), INFLAMMATION (Inflammed) and VERTIGO (Vertigo). The patient was treated with PARACETAMOL (TYLENOL) on 08-May-2021 for Adverse event, at a dose of 1 UNK and ELETRIPTAN HYDROBROMIDE (RELPAX) for Adverse event, at a dose of 1 dosage form as required. On 07-May-2021, PALPITATIONS (Heart racing), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (79-day gap of both doses) and VACCINATION SITE PAIN (vaccination site pain) had resolved. On 09-May-2021, MYALGIA (myalgia) had resolved. At the time of the report, BALANCE DISORDER (Lost balance/off balance spells. Spent 4 weeks lying down most of the time), DIZZINESS (Dizzy spell for about 3x / dizzy) and HEADACHE (horrible headaches / headaches come and go) had resolved, HEAD DISCOMFORT (Lots of pressure on her head/Headache feels like head is on lots of pressure,), FEELING HOT (Feels a little warm), MIGRAINE (Headaches Like a migraine), SWELLING (Something is swollen) and INFLAMMATION (Inflammed) outcome was unknown and VERTIGO (Vertigo) had not resolved.        mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosing remained unchanged.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   This case was linked to MOD-2021-123848 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 15-Jun-2021: Non-significant follow up appended