Graves' Disease Following COVID-19 Vaccination: A Population-based, Matched Case-control Study.

Objective: Multiple cases and case series reported Graves' disease (GD) following coronavirus disease 2019 (COVID-19) vaccination. We aimed to determine whether COVID-19 vaccination was associated with the incidence of GD.

Methods: We analyzed data from Clalit Health Services, the largest healthcare organization in Israel, which insures 4.7 million patients. A population-based, matched, case-control study was performed. Cases were defined as adult patients diagnosed with GD between December 2020 and November 2022. Each case was matched with controls in a 1:2 ratio. Each control was assigned an index date, which was identical to that of their matched case, defined as the date of GD diagnosis. Time between vaccination date and the diagnosis of GD or index date was assessed.

Results: A total of 726 patients with GD were matched with 1452 controls. The study patients and controls have received similar proportions of the COVID-19 vaccine [at least 1 dose: 80% (581/726) vs 77.8% (1129/1452), P = .22, respectively]. In a univariate analysis, at least 1 dose of the COVID-19 vaccine was not associated with the incidence of GD [odds ratio 95% confidence interval: 1.15 (.92-1.43)]. The mean time between first COVID-19 vaccination and the diagnosis of GD for cases or index date for controls was not significantly different [275.69 days (SD 144.37) for cases compared to 275.45 days (SD 145.76) for controls].

Conclusion: Our study found no association between COVID-19 vaccination and the incidence of GD.