Sudden sensorineural hearing loss after receiving an inactivated viral vaccine, Sinopharm: Two-case report

The prevalence of Coronavirus Disease 2019 is a global threat. Due to the high mortality rate caused by this disease, the vaccination is mandatory to protect patients against it and reduce the mortality. Rapid development and widespread use of vaccines have raised the possibility of adverse side effects over the course of administration and follow-up. In this study, we investigated an adverse event of sudden sensorineural hearing loss in two patients receiving first dose of Sinopharm, an inactivated viral vaccine. Both patients experienced sudden hearing loss in their left ear some days after receiving the first dose of the Sinopharm and had normal otoscopic examinations in both ears and mild to severe sensorineural hearing loss was reported in the left ear. After imaging evaluation with magnetic resonance imaging which showed no pathologic points. Two patients were treated with prednisolone and valacyclovir. Both patients experienced response and had good prognosis in their follow-up. Our study showed that there is no direct evidence of an association between Coronavirus Disease 2019 vaccination. A viral infection can cause sudden sensorineural hearing loss and should be considered as a possible side effect after vaccination. Although the number of side effects reported in clinical trials has been very low, long-term follow-up of patients is needed to assess the vaccine's safety, given the incidence of these cases.