Three Cases of Subacute Thyroiditis Following SARS-CoV-2 Vaccine: Post-vaccination ASIA Syndrome

İremli, Burçin Gönül; Şendur, Süleyman Nahit; Ünlütürk, Uğur

CONTEXT: Autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome) can be seen as a post-vaccination phenomenon that occurs after exposure to adjuvants in vaccines that increase the immune responses. There is very limited data regarding ASIA syndrome following SARS-CoV-2 vaccines. OBJECTIVES: This work aims to report cases of subacute thyroiditis related to the SARS-CoV-2 vaccine. METHODS: We describe the clinical, laboratory, and imaging features of three cases of subacute thyroiditis after inactivated SARS-CoV-2 vaccine (CoronaVac®). Three female healthcare workers have applied to our clinic with anterior neck pain and fatigue four to seven days after SARS-CoV-2 vaccination. Two of them were in the breastfeeding period. They were negative for thyroid antibodies, and there was no previous history of thyroid disease or upper respiratory tract infection, or COVID-19. Laboratory test results and imaging findings were consistent with subacute thyroiditis. RESULTS: SARS-CoV-2 vaccination can lead to subacute thyroiditis as a phenomenon of ASIA syndrome. Subacute thyroiditis may develop within a few days after the SARS-CoV-2 vaccination. Being in the postpartum period may be a facilitating factor for the development of ASIA syndrome after the SARS-CoV-2 vaccination. CONCLUSIONS: This is the first report of subacute thyroiditis as a phenomenon of ASIA syndrome after inactivated COVID-19 vaccination. Clinicians should be aware that subacute thyroiditis may develop as a manifestation of ASIA syndrome after the inactive SARS-CoV-2 vaccine.