Thyroid storm after coronavirus disease 2019 mRNA vaccination in a patient with a history of Graves' disease after coronavirus disease 2019 infection.

We report a case where the patient may have developed Graves' disease after COVID-19 infection, and where the COVID-19 vaccination may have exacerbated the condition, inducing the onset of a thyroid storm. Although any association between the vaccine and the onset of thyroid disease is impossible to demonstrate through a single case, the antecedent COVID-19 infection and COVID-19 messenger ribonucleic acid vaccination may have synergistically contributed to the development of Graves' disease followed by thyroid storm.