Study investigates new-onset tinnitus after COVID-19 vaccination

In a recently published study in The laryngoscoperesearchers examined the incidence of new-onset tinnitus after vaccination against coronavirus disease 2019 (COVID-19).

The growing prevalence of vaccination hesitation and fear of the side effects of messenger ribonucleic acid (mRNA) COVID-19 vaccine has become a major global public health concern. As a result, extensive research into the side effects of the COVID-19 vaccination has been conducted throughout the COVID-19 pandemic. Recently, tinnitus has attracted attention as a possible side effect of the mRNA COVID-19 vaccine. Following the COVID-19 vaccination, patients have reported developing life-changing tinnitus, which can accompany hearing loss, drastically affecting a patient’s quality of life.

About the study

In the present study, the 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 pneumococcal, and Tdap vaccines ( tetanus, diphtheria and acellular pertussis).

The TriNetX Analytics Network, a federated healthcare research network, collected anonymized electronic health record (EHR) data from over 78 million patients in 45 healthcare organizations (HCOs) across the United States. This data was used to create a retrospective cohort design. There were 78,058,186 patients with EHR in the US Collaborative Network of the TriNetX platform.

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

The data 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 received. To rule out the likelihood of COVID-19 vaccination within these three groups, three additional joint vaccination groups were evaluated during 2019.

The team defined a vaccination event as the first time a patient met the criteria in a specific time window, implying that the first COVID-19 dose was assessed in the first dose cohort. The second COVID-19 dosing group experienced exactly two documented vaccination events. A diagnosis of tinnitus in a patient with no history of the condition was termed new-onset tinnitus.

Results

Study results showed that within 21 days of receiving the first and second doses of mRNA COVID-19 vaccine, 0.038% of 2,575,235 participants and 0.031% of 1,477,890 participants were diagnosed with tinnitus. After the second dose of the COVID-19 vaccine, the likelihood of developing tinnitus was lower than after the first dose. Compared to the influenza group, tinnitus was reported by 998,991 influenza vaccine patients and 1,009,935 patients with first-dose COVID-19 vaccine. In addition, there were 720 cases of new tinnitus diagnosis in the influenza group and 374 cases in the first-dose COVID-19 group.

Compared to the Tdap cohort, there were a total of 444,708 Tdap vaccine patients and 444,721 first-dose COVID-19 vaccine patients. This 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 new encounter diagnosis of tinnitus in the pneumococcal vaccine patients, while 79 tinnitus cases occurred in the first-dose COVID-19 group.

Comparing the second COVID-19 dose group, 1,516,282 patients received the second dose of the COVID-19 vaccine while 1,516,282 patients received the first dose. Among them were 465 cases of a new tinnitus diagnosis in the second COVID-19 dose group and 577 new tinnitus cases in the first COVID-19 dose group.

Overall, study results showed that patients who received Tdap, influenza, and pneumococcal vaccines were more likely to develop tinnitus than those who received the first dose of the COVID-19 vaccine.