No association was found between COVID-19 vaccination and the occurrence of sudden sensorineural hearing loss (SSNHL), according to a cross-sectional, population-based study published in JAMA Otolaryngology–Head & Neck Surgery.

Previous research from Israel found cases where SSNHL occurred within weeks of patients receiving their first dose of the Pfizer COVID-19 vaccine between December 2020 and April 2021. However, the benefits of the COVID-19 vaccine outweigh its potential link to SSNHL, the researchers stated. These findings prompted the current study researchers to explore whether this potential association does, in fact, exist. Additionally, they examined whether emerging patterns in incident reports of the Centers for Disease Control and Prevention (CDC) Vaccine Adverse Events Reporting System (VAERS) during the initial 7 months of the US SARS-CoV-2 vaccination campaign — between December 14, 2020, and July 16, 2021— imply a link between COVID-19 vaccination and SSNHL.

The current analysis was carried out in 2 phases. In the initial phase, VAERS was queried for reports of SSNHL following SARS-CoV-2 vaccination in the 7-month study period. Cases that represented probable SSNHL were compiled, with the use of such search terms as deafness, deafness bilateral, deafness unilateral, deafness neurosensory, hypoacusis, and sudden hearing loss chosen as adverse events for data extraction.

A total of 555 incident reports in VAERS met the definition of probable SSNHL (mean time to symptom onset, 6 days; range, 0 to 21 days) over the period studied, which represented an annualized incidence estimate of 0.6 to 28.0 cases of SSNHL per 100,000 individuals per year. Of these incidents, 305 occurred among women and 250 occurred among men. The mean participant age was 54 years (range, 15 to 93 years).

Of the 3 manufacturers of the COVID-19 vaccines, 305 of the incidents involved the Pfizer-BioNTech vaccine, 222 involved the Moderna vaccine, and 28 involved the Janssen/Johnson & Johnson vaccine. The VAERS reporting rate of probable SSNHL was similar across the vaccine manufacturer groups (ie, 0.16 cases per 100,000 doses administered of both the Pfizer-BioNTech vaccine and the Moderna vaccine; 0.22 cases per 100,000 doses administered of the Janssen/Johnson & Johnson vaccine).

Additionally, a multi-institutional case series was performed to better understand the clinical profiles of patients who reported SSNHL following COVID-19 vaccination. Overall, 21 patients were identified across the study sites. Of these individuals, 13 were women; the mean age was 61 years (range, 23 to 92 years). Of the 21 patients, 6 had a history of autoimmune disease. Mean time to onset of SSNHL in the patients in the case series was 6 days (range, 0 to 15 days) following vaccination; 6 of the cases occurred at 7 days following vaccination. Of these 21 patients, 18 received treatment—9 with intratympanic steroids, 5 with oral corticosteroids, and 4 with both. A total of 14 patients had posttreatment audiometric data available, 8 of whom reported improvement after receiving treatment.

A major limitation of the case series is its lack of a comparison group (ie, a group that comprised patients who did not receive the COVID-19 vaccine but nevertheless experienced SSNHL within that same time frame).

“These results suggest that there is no association between vaccination and the development of SSNHL among adults who received a COVID-19 vaccine,” the researchers concluded. Additional prospective studies are warranted, to identify any potential links between COVID-19 vaccination and SSNHL in certain individuals.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Article originally appeared on Neurology Advisor