COVID-19 vaccination and thyroiditis.

At the end of 2019, the world began to fight the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2. Many vaccines have quickly been developed to control the epidemic, and with the widespread use of vaccines globally, several vaccine-related adverse events have been reported. This review mainly focused on COVID-19 vaccination-associated thyroiditis and summarized the current evidence regarding vaccine-induced subacute thyroiditis, silent thyroiditis, Graves' disease, and Graves' orbitopathy. The main clinical characteristics of each specific disease were outlined, and possible pathophysiological mechanisms were discussed. Finally, areas lacking evidence were specified, and a research agenda was proposed.

Association of Human Leukocyte Antigen Genotypes with Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine-Induced Subacute Thyroiditis.

Background: Despite mass vaccination, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-induced subacute thyroiditis (SAT) is rarely seen as a complication. The reason why some individuals are susceptible to developing vaccine-induced SAT is not known. SAT develops in genetically predisposed individuals who carry specific human leukocyte antigen (HLA) haplotypes. It is unknown whether specific HLA alleles are associated with SARS-CoV-2 vaccine-induced SAT. Objective: This study compared the HLA profiles of patients with SARS-CoV-2 vaccine-induced SAT to controls, to assess whether there is an association between specific HLA genotypes and development of SAT. The relationship between HLA genotypes and the clinical course of SARS-CoV-2 vaccine-induced SAT was also evaluated. Methods: A case-control study was conducted in a Turkish tertiary care center. Fourteen patients with SARS-CoV-2 vaccine-induced SAT and 100 healthy controls were included. HLA-A, HLA-B, HLA-C, HLA-DQB1, and HLA-DRB1 frequencies were analyzed by next-generation sequencing. Results: The frequencies of HLA-B*35 and HLA-C*04 alleles were significantly higher in SARS-CoV-2 vaccine-induced SAT cohort when compared with controls (HLA-B*35: 13 [93%] vs. 40 [40%], p < 0.001; HLA-C*04: 13 [93%] vs. 43 [43%], p < 0.001, respectively). More severe thyrotoxicosis was seen in patients having HLA-B*35 and HLA-C*04 homozygous alleles (free thyroxine: 4.47 ng/dL [3.77-5.18] vs. 1.41 ng/dL [1.22-2.63], p = 0.048). Inflammation tended to be more severe in homozygous patients (C-reactive protein: 28.2 mg/dL [13.6-42.9] vs. 4.8 [1.2-10.5], p = 0.07). Conclusions: The frequencies of HLA-B*35 and HLA-C*04 alleles were higher in SARS-CoV-2 vaccine-induced SAT compared with controls. Homozygosity for HLA-B*35 and HLA-C*04 was associated with thyrotoxicosis and a greater inflammatory reaction. Our findings should be confirmed in studies of other populations.

SARS-CoV-2 Vaccine-induced Thyroiditis: Safety of Revaccinations and Clinical Follow-up.

CONTEXT: The number of reported cases with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine-induced subacute thyroiditis (SAT) and Graves' disease (GD) is growing. However, active debate continues about managing such side effects and the safety of repeat or booster doses of the vaccines in such cases. OBJECTIVES: This study aims to present long-term clinical follow-up of SARS-CoV-2 vaccine-induced SAT or GD cases and provide data regarding the safety of revaccinations. METHODS: Patients diagnosed with SARS-CoV-2 vaccine-induced SAT or GD were included. Data regarding the long-term clinical follow-up of SARS-CoV-2 vaccine-induced SAT and GD cases and outcomes of repeat or booster SARS-CoV-2 vaccinations were documented. The literature, including cases of SARS-CoV-2 vaccine-induced SAT or GD, was reviewed. RESULTS: Fifteen patients with SARS-CoV-2 vaccine-induced SAT and 4 with GD were included. Pfizer/BioNTech COVID-19 vaccine (BNT162b2) was associated with symptoms in a majority of cases with SAT and all with GD. Median time from vaccination to symptom onset was 7 and 11.5 days, respectively, while 7 and 2 patients required medical treatment in SAT and GD groups, respectively. Remission was documented in 10 SAT patients, with a median time to remission of 11.5 weeks. No exacerbation/recurrence of SAT occurred in 7 of 9 patients who received a repeat vaccination dose, while symptoms of SAT worsened following the second vaccination in 2 cases. None of the patients experienced severe side effects that could be associated with revaccinations. CONCLUSIONS: Revaccinations appear to be safe in patients with SARS-CoV-2 vaccine-induced SAT cases, while more evidence is needed regarding SARS-CoV-2 vaccine-induced GD.

Three Cases of Subacute Thyroiditis Following SARS-CoV-2 Vaccine: Postvaccination ASIA Syndrome.

CONTEXT: Autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome) can be seen as a postvaccination phenomenon that occurs after exposure to adjuvants in vaccines that increase the immune responses. There are very limited data regarding ASIA syndrome following severe acute respiratory syndrome coronavirus 2 (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 3 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 4 to 7 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, 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.