Sudden hearing loss and COVID-19 vaccine: A potential signal?

ABSTRACT

Introduction: Vaccination against COVID-19 appears to be a promising approach to mitigate this pandemic. The French agency of medicinal products (ANSM) issued a signal concerning cases of sudden hearing loss (SHL) following vaccination with elasomeran (Spikevax® Moderna) [1] and AZD1222 (Vaxzevria® AstraZeneca) [2]. SHL is defined as a sensorineural hearing loss ≥30 dB within 72 hours [3]. We aimed to investigate the potential signal of SHL associated with COVID-19 vaccines. Material and methods: We queried VigiBase® (World Health Organization pharmacovigilance database), for all reports of "Sudden Hearing Loss" (MedDRA Preferred Term) related to "COVID-19 vaccine" (Active Ingredient), from 1967 to December 30, 2021 [4]. Disproportionality analysis was based on the Reporting Odds Ratio (ROR) with its 95% Confidence Interval (CI) and the Information Component (IC). A positive IC025 is statistically needed to confirm the detection of a signal [5]. Results: In VigiBase®, 1,602 cases of COVID-19 vaccine-associated SHL were collected. Tozinameran (Pfizer-BioNTech) was mostly notified with 1,053 (65.7%) reports, followed by elasomeran (Moderna, 281, 17.5%), AZD1222 (AstraZeneca, 217, 13.5%), and JNJ 78436735 (Janssen, 43, 2.7%). Most cases concerned women (885, 55.2%), with a median age of 51 years, and 827 (51.6%) were considered serious. The association of COVID-19 vaccines and SHL showed significant disproportionality, with a ROR of 7.4 (95% CI 6.9-7.9) and an IC025>0. Tozinameran reached the strongest ROR (8.2;95% CI 7.6-8.8), followed by elasomeran (4.6;95% CI 4.0-5.2), JNJ-78436735 (3.0;95% CI 2.2-4.0), and AZD1222 (2.7;95% CI 2.3-3.1), all with IC025>0. Discussion/Conclusion: Significant disproportionality was identified for COVID-19 vaccines and SHL. Even though this adverse drug event may rely on an inflammatory mechanism, causality cannot be established by this pharmacovigilance study. However, this finding may strengthen the signals issued by ANSM, concerning elasomeran and AZD1222. SHL following COVID-19 vaccination might be evoked and treated as soon as possible.