Subacute THYROiditis Related to SARS-CoV-2 VAccine and Covid-19 (THYROVAC Study): A Multicenter Nationwide Study

Subacute Thyroiditis Following COVID-19 and COVID-19 Vaccination

OBJECTIVE

COVID-19 infection and immunizations have been implicated in developing a range of thyroid diseases, including subacute thyroiditis (SAT). This study aimed to evaluate the association between COVID-19 infection and/or COVID-19 vaccination with SAT.

METHODS

A population of 3 million adults insured by Clalit Health Services was evaluated from March 2020 to September 2022. Patients with a new diagnosis of SAT were identified and matched in a 1:10 ratio to a control group. Each control was assigned an index date that was identical to that of their matched case, defined as the date of SAT diagnosis. Multivariate conditional logistic regression models were used to evaluate the association between COVID-19 infection, vaccine, and thyroiditis.

RESULTS

A total of 3221 patients with SAT were matched with 32 210 controls. Rates of COVID-19 vaccination (first, second, or third dose) and COVID-19 infection were evaluated prior to the date of SAT diagnosis (disease group) or index date (control group) to detect a possible association. No difference was detected between the groups in relation to vaccinations at the 30 days, 60 days, and 90 days of time points (P = .880/0.335/0.174, respectively). No difference was found between groups in relation to COVID-19 infection at these time points (P = .735/0.362/0.956, respectively). There was higher use of medications for the treatment of thyroiditis, including nonsteroidal anti-inflammatory drugs (28.6% vs 7.9%, P < .01), steroids (10.3% vs 1.8%, P < .01), and beta-blockers (18.3% vs 5.4%, P < .01).

CONCLUSION

Based on this large population study, no association was found between COVID-19 infection and/or the COVID-19 vaccine and SAT.

SARS-CoV-2-Vaccine-Related Endocrine Disorders: An Updated Narrative Review

The emergence of the COVID-19 pandemic has led to the rapid and worldwide development and investigation of multiple vaccines. While most side effects of these vaccines are mild and transient, potentially severe adverse events may occur and involve the endocrine system. This narrative review aimed to explore the current knowledge on potential adverse endocrine effects following COVID-19 vaccination, with thyroid disorders being the most common. Data about pituitary, adrenal, diabetes, and gonadal events are also reviewed. This review also provides a comprehensive understanding of the pathogenesis of endocrine disorders associated with SARS-CoV-2 vaccines. PubMed/MEDLINE, Embase database (Elsevier), and Google Scholar searches were performed. Case reports, case series, original studies, and reviews written in English and published online up to 31 August 2023 were selected and reviewed. Data on endocrine adverse events of SARS-CoV-2 vaccines are accumulating. However, their causal relationship with COVID-19 vaccines is not strong enough to make a definite conclusion, and further studies are needed to clarify the pathogenesis mechanisms of the endocrine disorders linked to COVID-19 vaccines.

Thyroid dysfunction in COVID-19

The COVID-19 pandemic has affected over 772 million people globally. While lung damage is the major contributor to the morbidity and mortality of this disease, the involvement of multiple organs, including the endocrine glands, has been reported. This Review aims to provide an updated summary of evidence regarding COVID-19 and thyroid dysfunction, incorporating highlights of recent advances in the field, particularly in relation to long COVID and COVID-19 vaccination. Since subacute thyroiditis following COVID-19 was first reported in May 2020, thyroid dysfunction associated with COVID-19 has been increasingly recognized, secondary to direct and indirect effects on the hypothalamic-pituitary-thyroid axis. Here, we summarize the epidemiological evidence, pattern and clinical course of thyroid dysfunction following COVID-19 and examine radiological, molecular and histological evidence of thyroid involvement in SARS-CoV-2 infection. Beyond acute SARS-CoV-2 infection, it is also timely to examine the course and implication of thyroid dysfunction in the context of long COVID owing to the large population of survivors of COVID-19 worldwide. This Review also analyses the latest evidence on the relationship between the therapeutics and vaccination for COVID-19 and thyroid dysfunction. To conclude, evidence-based practice recommendations for thyroid function testing during and following COVID-19 and concerning COVID-19 vaccination are proposed.