Graves' hyperthyroidism following COVID-19 vaccination: a multicenter case series and literature review

Since the introduction of COVID-19 vaccination, cases of Graves' disease (GD) occurring shortly after immunization have been reported. This study compared the clinical, biochemical and imaging features of GD diagnosed after vaccination with those of other newly diagnosed GD cases.

A multicenter retrospective case series was conducted in three university hospitals in Brussels, Belgium. Adults diagnosed with de novo GD between 1 January 2021 and 31 October 2022 were included. Patients were categorized into three groups according to vaccination status and timing of disease onset: early-onset GD (≤30 days) after COVID-19 vaccination, later-onset GD (>30 days), and GD in unvaccinated individuals. A literature review of peer-reviewed case reports and case series of de novo GD following COVID-19 vaccination was also performed.

A total of 160 patients were included: 17 with early-onset post-vaccination GD, 57 with later-onset disease, and 86 unvaccinated at GD diagnosis. No significant differences were observed between the three groups with respect to biochemical, imaging or initial treatment characteristics. Age differed significantly between groups, with patients in the later-onset group being older (p = 0.002). The literature review identified 51 published cases of de novo GD following COVID-19 vaccination, most occurring within the first weeks after vaccination.

In this multicenter retrospective series, GD diagnosed after COVID-19 vaccination did not demonstrate a distinct clinical, biochemical or imaging phenotype compared with GD in unvaccinated individuals. Standard diagnostic and therapeutic strategies for GD therefore remain appropriate, irrespective of COVID-19 vaccination status or timing.