Four cases of audio-vestibular disorders related to immunisation with SARS-CoV-2 mRNA vaccines.

Objective: To gain medical insight into the clinical course and safety of otolaryngologic disorders following immunisation with severe acute respiratory coronavirus (SARS-CoV-2) mRNA-based vaccines.

Design: Case description.

Study Sample: We report four cases of transient audio-vestibular symptoms, which occurred shortly after inoculation of two BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna®) vaccines.

Results: Hearing loss was unilateral in all cases and recovered at least partially: it was associated with persistent gait instability in two cases, after 1 and 7 months. Trigger mechanisms underpinning audio-vestibular impairment remain uncertain. Immune tolerance mechanisms with off-target innate activation of T-lymphocytes may be involved in vestibulocochlear nerve disorders, as for other cranial nerves involvement.

Conclusions: The occurrence of audio-vestibular manifestations following mRNA-based vaccines needs ENT monitoring to support their causality in such rare vaccine-related adverse events. Audio-vestibular disorders appeared of transitory nature, including hearing loss, and should not deter further efforts in large-scale vaccination campaigns against SARS-CoV-2.