lost most of the hearing in my good ear/been unable to hear from her right (good) ear; people were talking and I couldn't understand anything when people were talking, she could not understand what they were saying. The words were not clear; All of a sudden, when she got up in the morning, she couldn't hear anything; This spontaneous case was reported by a consumer and describes the occurrence of SUDDEN HEARING LOSS (All of a sudden, when she got up in the morning, she couldn't hear anything) and DEAFNESS (lost most of the hearing in my good ear/been unable to hear from her right (good) ear) in a 78-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 091D21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Deafness left ear. Concomitant products included COLECALCIFEROL (VITAMIN D3), FLUOXETINE HYDROCHLORIDE (PROZAC), ATORVASTATIN, METOPROLOL, ATORVASTATIN CALCIUM (LIPITOR), ZOLPIDEM TARTRATE (AMBIEN), LORAZEPAM (ATIVAN) and CETIRIZINE HYDROCHLORIDE (ZYRTEC ALLERGY) for an unknown indication.    On 25-Oct-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 18-Nov-2021, the patient experienced SUDDEN HEARING LOSS (All of a sudden, when she got up in the morning, she couldn't hear anything) (seriousness criterion medically significant) and HYPOACUSIS (people were talking and I couldn't understand anything when people were talking, she could not understand what they were saying. The words were not clear). On an unknown date, the patient experienced DEAFNESS (lost most of the hearing in my good ear/been unable to hear from her right (good) ear) (seriousness criterion medically significant). At the time of the report, SUDDEN HEARING LOSS (All of a sudden, when she got up in the morning, she couldn't hear anything), DEAFNESS (lost most of the hearing in my good ear/been unable to hear from her right (good) ear) and HYPOACUSIS (people were talking and I couldn't understand anything when people were talking, she could not understand what they were saying. The words were not clear) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 19-Nov-2021, Acoustic stimulation tests: hearing has gone down to 50% of original (abnormal) Hearing has gone down to 50% of original.         No treatment information was reported.  Company comment: This case concerns a 78 year old female with relevant medical history of Deafness in the left ear, who experienced Serious ( medically significant  ) unexpected events of Sudden hearing Loss , Deafness and non-serious unexpected event of hypoacusis which occurred  25 days after vaccination with the 3rd dose ( booster dose) of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine). Acoustic stimulation test was done which showed that the hearing went down by 50% in the right  ear. The re-challenge for this case is not applicable since the events outcome were reported as unknown and the events reported occurred on the 3rd dose ( booster dose ) and no additional doses will be given. The age of the patient and the condition of hearing loss in the L ear is a confounder for this case . ( elderly patients are prone to hearing loss as a result of aging) . The benefit -risk relationship of mRNA -1273 ( Moderna Covid 19 Vaccine) is not affected by this report.; Sender's Comments: This case concerns a 78 year old female with relevant medical history of Deafness in the left ear, who experienced Serious ( medically significant  ) unexpected events of Sudden hearing Loss , Deafness and non-serious unexpected event of hypoacusis which occurred  25 days after vaccination with the 3rd dose ( booster dose) of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine). Acoustic stimulation test was done which showed that the hearing went down by 50% in the right  ear. The re-challenge for this case is not applicable since the events outcome were reported as unknown and the events reported occurred on the 3rd dose ( booster dose ) and no additional doses will be given. The age of the patient and the condition of hearing loss in the L ear is a confounder for this case . ( elderly patients are prone to hearing loss as a result of aging) . The benefit -risk relationship of mRNA -1273 ( Moderna Covid 19 Vaccine) is not affected by this report.