Revaccination with different COVID-19 vaccine; Interchange of vaccine products; She thought she passed out; Seizure; sick; body stiff/ body got clunched; turned red; Jaw clunched; really bad side effect; felt like not breathing; might be an allergic reaction; nausea; This spontaneous case was reported by a consumer and describes the occurrence of LOSS OF CONSCIOUSNESS (She thought she passed out) and SEIZURE (Seizure) in a 65-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 013B22) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Previously administered products included for Product used for unknown indication: Pfizer Biontech (Dose 1) on 01-Jul-2021, Pfizer Biontech (Dose 2) on 28-Jul-2021 and Pfizer Biontech (Dose 3) on 15-Dec-2021. Past adverse reactions to the above products included No adverse event with Pfizer Biontech, Pfizer Biontech and Pfizer Biontech. Concurrent medical conditions included Penicillin allergy, Sulfonamide allergy, Arrhythmia (Started 15 years ago, and no recent change in status such as improvement or worsening), Pre-diabetic (after having Covid-19 her Dr diagnosed her with diabetes type 2 and no recent change in status such as improvement or worsening) since 1995 and Type 2 diabetes mellitus (diagnosed after having COVID-19). Concomitant products included ATORVASTATIN, ALPRAZOLAM (XANAX) and CALCIUM CARBONATE, COLECALCIFEROL (CALCIUM + VITAMIN D [CALCIUM CARBONATE;COLECALCIFEROL]) for an unknown indication.    On 23-Jul-2022, the patient received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 23-Jul-2022, the patient experienced LOSS OF CONSCIOUSNESS (She thought she passed out) (seriousness criterion medically significant), SEIZURE (Seizure) (seriousness criterion medically significant), ILLNESS (sick), MUSCULOSKELETAL STIFFNESS (body stiff/ body got clunched), ERYTHEMA (turned red), JAW DISORDER (Jaw clunched), IMMUNISATION REACTION (really bad side effect), DYSPNOEA (felt like not breathing), HYPERSENSITIVITY (might be an allergic reaction) and NAUSEA (nausea). On an unknown date, the patient experienced COVID-19 IMMUNISATION (Revaccination with different COVID-19 vaccine) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). At the time of the report, LOSS OF CONSCIOUSNESS (She thought she passed out), SEIZURE (Seizure), ILLNESS (sick), MUSCULOSKELETAL STIFFNESS (body stiff/ body got clunched), ERYTHEMA (turned red), JAW DISORDER (Jaw clunched), IMMUNISATION REACTION (really bad side effect), DYSPNOEA (felt like not breathing), HYPERSENSITIVITY (might be an allergic reaction) and NAUSEA (nausea) was resolving and COVID-19 IMMUNISATION (Revaccination with different COVID-19 vaccine) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 13-Mar-2021, SARS-CoV-2 test: (Positive) Positive.         Concomitant medications also included Natropol 100 mg.  The patient  received fourth dose as a booster from Moderna on 23-Jul-2022, that night she got sick, her body went stiff, her body got clunched, she felt like she was not breathing, she said it was a really bad side effect, got nausea, she thought she passed out, her jaw clunched, she turned red, her husband said she had a seizure and while trying to help her she almost took one finger out of him. She said she was afraid of taking the new booster. The patient's brother in law, who has a Phd, said that that might be an allergic reaction to one of the components (liquid agents) of the vaccine that transports mRNA.  Treatment information was not provided.  Company Comment: This spontaneous case concerns a 65-year-old female patient with no relevant medical history reported, who experienced the unexpected serious (medically significant) AESI of Seizure and unexpected serious (medically significant) event of Loss of consciousness which occurred on the same day after the fourth dose of mRNA-1273 vaccine in covid-19 vaccination series. After the vaccination patient got sick, her body went stiff and got clunched, felt like not breathing, she said it was a bad side effect, got nausea, she thought she passed out, her jaw clunched, she turned red, and her husband said she had a seizure. Additionally, Covid-19 immunisation and Interchange of vaccine products is also noted in this case as the patient received three doses with covid-19 vaccine Pfizer Biontech prior to the current vaccination. No further information on clinical course, investigations and treatment received was available in the report. The outcome of the events was reported as resolving. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.; Sender's Comments: This spontaneous case concerns a 65-year-old female patient with no relevant medical history reported, who experienced the unexpected serious (medically significant) AESI of Seizure and unexpected serious (medically significant) event of Loss of consciousness which occurred on the same day after the fourth dose of mRNA-1273 vaccine in covid-19 vaccination series. After the vaccination patient got sick, her body went stiff and got clunched, felt like not breathing, she said it was a bad side effect, got nausea, she thought she passed out, her jaw clunched, she turned red, and her husband said she had a seizure. Additionally, Covid-19 immunisation and Interchange of vaccine products is also noted in this case as the patient received three doses with covid-19 vaccine Pfizer Biontech prior to the current vaccination. No further information on clinical course, investigations and treatment received was available in the report. The outcome of the events was reported as resolving. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.