Hearing loss and tinnitus associated with COVID-19 vaccines: An analysis from the national pharmacovigilance database in Malaysia

To compare the reporting pattern of hearing loss and tinnitus across different vaccines brands used in Malaysia (BNT162b2, CoronaVac, ChAdOx1, Ad5.CoV2-S and BBIBP-CorV). This retrospective study included all reports of hearing loss and tinnitus occurring after COVID-19 vaccination that were received in the national pharmacovigilance database, QUEST, from February 24, 2021 through July 31, 2022. Reports given causality consistent or indeterminate were included. There were 21 cases of hearing loss, with overall reporting rate of 0.29 cases per million doses. The rate was similar across BNT162b2, CoronaVac and ChAdOx1. For tinnitus, 35 cases were reported, with the overall reporting rate of 0.49 cases per million doses, and the highest rate was reported for ChAdOx1. For both events, most cases aged 30 to 49 years. No gender disparity was observed. Both events were mainly reported to have occurred after the primary doses, with a median time-to-onset of two days. There were no statistically significant differences in the reporting patterns for both events across BNT162b2, CoronaVac and ChAdOx1 by age group, gender, race, and dose number. Despite the low reporting rates and insufficient evidence to confirm its relationship, hearing loss and tinnitus following vaccinations should not be ignored due to its disabling potential and impact on one's quality of life. Continual reporting is encouraged for better signal characterization in the future.