Abstract
Graves' disease is an autoimmune thyroid disorder characterized by the production of thyroid-stimulating hormone receptor antibodies and is one of the leading causes of hyperthyroidism. While both genetic and environmental factors are involved in its onset, the detailed mechanisms remain unclear. The COVID-19 pandemic led to the development and global distribution of mRNA vaccines, such as BNT162b2, to combat SARS-CoV-2. However, concerns have arisen regarding the potential exacerbation of autoimmune diseases following vaccination. This report presents a case of a 48-year-old male with Graves' disease, treated with 2.5 mg/day of thiamazole (MMI), who developed symptoms such as fatigue, hand tremors, and exertional dyspnea on the seventh day after receiving the first dose of the BNT162b2 vaccine. Laboratory findings confirmed severe thyrotoxicosis, and he was diagnosed with an exacerbation of Graves' disease. His condition improved with an increased MMI dosage and supportive therapy. The possible mechanisms for Graves' disease exacerbation include molecular mimicry between the SARS-CoV-2 spike protein and thyroid antigens, as well as immune activation by vaccine adjuvants. Several recent reports, including this case, highlight the importance of careful monitoring of patients with pre-existing autoimmune diseases after vaccination. This case underscores the need for early diagnosis and prompt intervention in managing post-vaccination autoimmune disease exacerbations. Further research is required to clarify the causal relationship between vaccines and autoimmune disease flares, identify risk factors, and establish preventive measures. Additionally, both healthcare providers and patients must remain vigilant for potential health changes following vaccination and seek medical attention promptly.