mRNA COVID-19 Vaccines Induced-Sudden Sensorineural Hearing Loss (SSNHL): Descriptive Analysis of French Pharmacovigilance Database (FPDB): An International Journal of Medical Toxicology and Drug Experience

ABSTRACT

Introduction: Several case reports and pharmacoepidemiological studies suggested a potential association between the mRNA) COVID-19 vaccine, tozinameran (Comirnaty) and elasomeran (Spikevax) and SSNHL. However, data remain controversed because of scarcity of this adverse effect (1,2). Objective: To assess an descriptive analysis of all spontaneous reporting of mRNA COVID-19 vaccines induced-Sudden Sensorineural Hearing Loss (SSNHL) to the French Pharmacovigilance system and to estimate the incidence of SSNHL reported cases. Methods: All cases of mRNA COVID-19 vaccines induced-SSNHL recorded in the FPDB from the beginning of the campaign of COVID19 vaccination in France until 2 February 2022 were included. Following data were collected demographic data (age, gender), risk factors, history of immunologic disease, other factors leading to SSNHL (trauma, infections,...), the range and the month of vaccination, the delay of onset of SSNHL, associated symptoms (dizziness and tinnitus), the degree of hearing loss and the outcome. Audiogramm and/or medical reports were requested in order to guarantee a better informativeness of data. All cases were reviewed by a staffincluding two pharmacologists and two otorhinolaryngologists. All cases with a delay onset[30 days were excluded. Cases were split in "well completed" and (non completed) based on the availability of audiogram and medical reports. Results: A total of 250 cases were recorded during this period for the 2 vaccines (60 Spikevax/190) (23 cases excluded because of other reasons or missed data). 226 cases were analyzed and will described according to over mentioned criteria, corresponding to 151 cases classed as "well completed" (31 Spikevax/120 Comirnaty). The estimated incidence of SSNHL was estimated as 0.18/100000 for serious cases for Comirnaty and 0.27/100000 for both serious and non serious cases for Spikevax. For Spikevax, the median age was 50 years with a sex ratio of 0.9, the half of cases occurred after D1, 5 cases of positive rechallenge and hearing loss was associated with tinnitus in 50% and dizziness in 21.6%. For Comirnaty, the median age was 56 years with a sex ratio of 0.8, 76% of cases occurred after D1, 1 case of positive rechallenge, associated with tinnitus in 84% and dizziness in 39% of cases. Conclusion: In our knowledge, it is the first study analysing all cases of mRNA vaccines-induced SSNHL supporting by audiogram analysis. This adverse effect remains rare but should be considered in patients with audio-vestibular risk factors. Other studies would be necessary in order to understand the mechanism which remains unclear.