(14.16) mRNA (SARS-CoV-2) vaccine-induced hyperthyroidism - Learnings Based on the Meta-Analysis

We searched multiple databases, including Medline, Web of Science, Cochrane Library, PubMed, Embase, and conference proceedings from inception to November 2023, for articles reporting GD and SAT following the COVID-19 mRNA vaccine (Pfizer and Moderna).

Results: We analyzed 77 cases (38 cases of GD and 39 cases of SAT) published in the literature. GD group included 10 males (mean age = 44) and 28 females (mean age = 41.89), and the SAT group included 13 males (mean age = 45.36) and 26 female patients (mean age = 41.12). In GD group, 21 patients (55.3%) developed hyperthyroidism symptoms after 1st dose of mRNA vaccine, while 17 patients (44.7%) showed symptoms after 2nd dose (p = 0.05), and only two patients (5.3 %) showed signs after 3rd dose; 35 patients (92.1 %) with GD were Thyrotropin receptor Antibody (TRAb) positive, and 3 patients (7.9 %) were Thyroid Stimulating Immunoglobulin (TSI); 17 out of 23 patients who were tested (74.0 %) were anti-thyroid peroxidase Antibody (Anti-TPO) positive, while 6 (26 %) were negative. 15 out of 21 patients who were tested (71.4 %) had positive Anti-Thyroglobulin antibody (Anti-Tg), but 6 patients (28.6 %) were negative for anti-Tg. In the SAT group, 21 patients (53.8 %) showed hyperthyroidism symptoms after the 1st dose, 17 patients (43.6 %) after the 2nd dose, and 2 patients (5.1 %) showed symptoms after the 3rd dose. Interestingly, positive anti-TPO was only seen in 5 out 32 patients who were tested (15.6 %), and 32 patients (74.4 %) were negative for Anti-TPO. 11 out of 33 patients who were tested (33.3 %) were positive for Anti-Tg, 22 patients (66.6 %) were negative. 

Discussion/Conclusion:

This study is the first review to analyze the characteristics of mRNA COVID-19 vaccine-associated hyperthyroidism etiology, including GD and SAT. Based on our data, both diseases are predominant in females, with a mean age of 41, while for men, with a mean age of 44-45. Most cases developed hyperthyroidism symptoms after the first dose of the mRNA vaccine, GD (55.3%) and SAT (53.8%), respectively, and less happened in the second dose, 17% for GD and 17% for SAT, and least with third dose, 5% for GD and 2.6% for SAT. Interestingly, the time of onset for these two groups are different: after 1st dose, GD needs 40.4 ± 18.5 days, but SAT only needs10.8 ± 7.2 days (p=0.06); after the 2nd dose, GD needs 30.1 ± 27.5 days while SAT needs 15.8 ± 10.0 days ( p=0.05). In addition, the TPO and anti-Tg antibodies were more likely to be present in GD than in the SAT groups.