Four cases of Graves' disease following viral vector severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) vaccine.

Mass immunization has led to a decrease in the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) worldwide. At the same time, awareness regarding possible adverse effects of newly developed vaccines is critical. The present study was undertaken to report the cases of Graves' disease occurring after administration of viral vector vaccine (ChAdox1nCoV-19) and describe the clinical profile, response to treatment, and effect of administration of a second dose in patients developing Graves' disease. Four cases of Graves' disease after administration of the vaccine were noted. Two of these had a mild thyroid eye disease. Three cases were female and had a family/self-history of autoimmune disease. All cases responded well to treatment and became euthyroid within two to four months. Two patients exhibited worsening thyrotoxicosis after receiving a second dose of the vaccine. We propose that the temporal relationship between administration of the vaccine and the onset of symptoms establishes Graves' disease as an adverse event after the SARS-CoV-2 viral vector vaccine. Close follow-up is advisable in individuals developing Graves' disease after SARS-CoV-2 vaccination.