by Ingrid Hein, Staff Writer, MedPage Today December 16, 2022
Sudden sensorineural hearing loss (SSNHL) was not associated with receipt of COVID-19 vaccination, a register-based country-wide retrospective cohort study in Finland showed.
Among 5.5 million Finnish residents, the adjusted incidence rate ratios (aIRRs) of SSNHL with the Pfizer-BioNTech mRNA COVID vaccine’s three doses were 0.8 (95% CI 0.6-1.0), 0.9 (95% CI 0.6-1.2), and 1.0 (95% CI 0.7-1.4), respectively, compared with incidence before the pandemic, reported Petteri Hovi, MD, PhD, of the Finnish Institute for Health and Welfare in Helsinki, and colleagues.
“Within the COVID-19 vaccinated population, the incidence of SSNHL did not show a temporal pattern associated with vaccination, and the incidences during the main risk periods were similar to the incidences before vaccination and those after the main risk periods,” they noted in JAMA Otolaryngology-Head & Neck Surgery.
The crude incidences of SSNHL from 0 to 54 days following the first COVID vaccine dose were:
“The main [0 to 54 days] and secondary risk periods [≥55 days] following the second and third vaccinations showed no significant differences to the pre-epidemic unvaccinated time in the adjusted analysis,” Hovi and team wrote. “The point estimates for the aIRRs varied between 0.7 and 1.2, and all confidence intervals included 1.”
In addition, the researchers found no association between increased incidence of SSNHL and SARS-CoV-2 infection in the main risk period (aIRR 1.1, 95% CI 0.7-1.8), nor in the secondary risk period (aIRR 1.1, 95% CI 0.7-1.6), “both suggesting no significant change in the incidence of SSNHL compared with the uninfected time.”
SSNHL, a rare, severe condition, affects about 5 to 20 per 100,000 people per year in high-income countries, Hovi and team said. Hearing recovers in 40% to 60% of cases over a period of a few weeks.
A previous population-based study out of Israel suggested a possible association between increased risk of SSNHL and the Pfizer vaccine, but Hovi and team noted that confounding was likely. Meanwhile, a U.S. study using data from CDC’s Vaccine Adverse Events Reporting System showed no association.
Hovi and colleagues included 5.5 million Finnish residents in their study conducted from January 2019 to April 20, 2022. Residents who had a diagnosis of SSNHL from 2015 to 2018 were excluded.
Before the COVID pandemic began in Finland, 18.7 per 100,000 people had received a diagnosis of SSNHL annually.
Analyses were adjusted for calendar time, sex, age, diabetes, cardiovascular disease, other chronic diseases, and the number of primary care visits.
The researchers noted that some people may have been misclassified as uninfected when they may have been infected, but not confirmed by a test. Another limitation is that SSNHL was defined according to the diagnostic decision of clinicians and not a standardized predefined definition.
“Clearly, future research should be based on objective findings that fulfill international criteria for SSNHL, and all included audiograms should be reevaluated,” they wrote. “Studies with more detailed clinical data would be needed to reproduce this study with a more objective diagnosis of sudden hearing loss.”
Ingrid Hein is a staff writer for MedPage Today covering infectious disease. She has been a medical reporter for more than a decade. Follow
Disclosures
Hovi reported no disclosures.
Lead author Nieminen reported being employed by the Finnish Institute for Health and Welfare, which received research funding from Sanofi Pasteur, GSK, and Pfizer, and also reported receiving funding from Sanofi Pasteur outside the submitted work. A co-author reported serving as the secretary of the Finnish National Immunization Technical Advisory Group.
Primary Source
JAMA Otolaryngology-Head & Neck Surgery
Source Reference: Nieminen TA, et al “Sudden hearing loss following vaccination against COVID-19” JAMA Otolaryngol Head Neck Surg 2022; DOI: 10.1001/jamaoto.2022.4154.
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