Sudden Sensorineural Hearing Loss and COVID-19 vaccines
Until January 10th 2023, the Netherlands Pharmacovigilance Centre Lareb received 109 reports of Sudden Sensorineural Hearing Loss (SSNHL) following COVID-19 vaccination. Based on the reports, no conclusion can be made about a possible relationship between SSNHL and the COVID-19 vaccines. Therefore, Lareb recommends more research.
Sudden sensorineural hearing loss (SSNHL) is commonly defined as an acute onset (<72 hr) hearing loss of 30 dB or greater over at least three contingent audiometric frequencies. Possible causes of SSNHL are infections, autoimmune diseases, neoplasms, ototoxic drugs, trauma, vascular-, psychiatric-, metabolic- and neurologic disorders. Most cases however, remain idiopathic.
Lareb reports
In the majority of the reports of SSNHL occurred within 10 days after vaccination. SSNHL has been reported after administration of all types of COVID-19 vaccines. Treatment - mainly prednisone - was prescribed in 82 cases (75.2%) and an audiogram was performed in 48 cases (44.0%). 20% of the patients had recovered from SSNHL, whereas 50% of the patients was not recovered at the time of reporting.
Number of reports not higher than expected
The total number of reports received is compared to the background incidence rates of SSNHL. The number of reports was not higher than expected based on the background incidence rates. Only after the first dose of the Pfizer vaccine in women between 18-34 years old the number of reports was higher than expected. This only counts for a very small proportion of reports (3 of the 109), so no conclusion can be drawn about the relationship of SSNHL and the COVID-19 vaccines. Therefore, Lareb recommends more research.