Study explores new-onset tinnitus after COVID-19 vaccination

In a recent study published in The Laryngoscope, researchers assessed the incidence of new-onset tinnitus after coronavirus disease 2019 (COVID-19) vaccination.

The growing prevalence of vaccine hesitancy and anxiety about the messenger ribonucleic acid (mRNA) COVID-19 vaccine's side effects has become an important global health concern. As a result, throughout the COVID-19 pandemic, extensive research has been conducted on the adverse effects of COVID-19 vaccination. Recently, tinnitus has drawn attention as a possible side effect of the mRNA COVID-19 vaccine. Following COVID-19 vaccination, patients have reported the development of life-altering tinnitus that may be accompanied by hearing loss, thus drastically damaging a patient's quality of life.

About the study

In the present study, researchers determined the proportion of patients who experienced new-onset tinnitus within 21 days of receiving the COVID-19 vaccine compared to those who received influenza, polysaccharide pneumococcus, and Tdap (tetanus, diphtheria, and acellular pertussis) vaccines.

The TriNetX Analytics Network, a federated health research network, collected de-identified electronic health record (EHR) data from over 78 million patients across 45 health care organizations (HCOs) in the US. This data was employed to create a retrospective cohort design. In the US Collaborative Network of the TriNetX platform, there were 78,058,186 patients with any EHR.

Five patient groups were identified: (1) those who were administered the first mRNA COVID-19 vaccine dose between 15 December 2020 and 1 March 2022, (2) those who received their second mRNA COVID-19 vaccine dose between 15 December 2020 and 1 March 2022, (3) those who received the influenza vaccine between 1 January 2019 and 1 December 2019, (4) those who received Tdap vaccine between 1 January 2019 and 1 December 2019, and (5) those who received pneumococcal vaccine between 1 January 2019 and 1 December 2019.

The dates corresponding to the COVID-19 vaccination group ranged from the first day of COVID-19 vaccination in the US to a hypothetical date that provided a window of more than three weeks before the data was obtained. To rule out the likelihood of COVID-19 vaccination within these three groups, three additional common vaccination groups were evaluated throughout 2019.

The team defined a vaccination event as the first time a patient fulfilled the criteria in a specific time window, implying that the first COVID-19 dose was assessed in the first dose cohort. The COVID-19 second dosage group experienced precisely two documented vaccination procedures. The diagnosis of tinnitus in a patient with no prior history of the condition was referred to as new-onset tinnitus.

Results

The study results showed that within 21 days of receiving their first and second dose of the mRNA COVID-19 vaccine, 0.038% of the 2,575,235 participants and 0.031% of the 1,477,890 participants were diagnosed with tinnitus. Following the second dose of the COVID-19 vaccine, there was a decreased likelihood of experiencing tinnitus than following the first dose. Compared to the influenza group, tinnitus was reported by 998,991 influenza vaccine patients and 1,009,935 first-dose COVID-19 vaccine patients. Furthermore, there were 720 cases of a new diagnosis of tinnitus in the influenza group and 374 cases in the first dose COVID-19 group.

As compared to the Tdap cohort, there were a total of 444,708 Tdap vaccine patients and 444,721 first-dose COVID-19 vaccine patients. These included 314 cases of a new tinnitus diagnosis in the Tdap group and 133 new tinnitus cases in the first dose COVID-19 group. in the case of the polysaccharide pneumococcal vaccine group, the team found 153,344 pneumococcal vaccine patients compared to 154,825 patients who received their first dose of the COVID-19 vaccine. Among these, there were 132 cases of a new encounter diagnosis of tinnitus in the pneumococcal vaccine patients, while 79 tinnitus cases occurred in the first dose COVID-19 group.

In comparing the COVID-19 second dose group, 1,516,282 patients received the second dose of the COVID-19 vaccine, while 1,516,282 patients received the first dose. These included 465 cases of a new diagnosis of tinnitus in the COVID-19 second dose group and 577 new tinnitus cases in the COVID-19 first dose group.

Overall the study findings showed that patients had a higher chance of experiencing tinnitus after receiving Tdap, influenza, and pneumococcus vaccines than after the first dose of the COVID-19 vaccine.

Written by

Bhavana Kunkalikar

Bhavana Kunkalikar is a medical writer based in Goa, India. Her academic background is in Pharmaceutical sciences and she holds a Bachelor's degree in Pharmacy. Her educational background allowed her to foster an interest in anatomical and physiological sciences. Her college project work based on ‘The manifestations and causes of sickle cell anemia’ formed the stepping stone to a life-long fascination with human pathophysiology.