Endocrine system after 2 years of COVID-19 vaccines: A narrative review of the literature

Purpose: The purpose of this study was to describe the current knowledge on the potential endocrine adverse effects post-COVID-19 vaccines. Methods: A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Case reports, case series, original studies, and reviews written in English and published online up to 31 July 2022 were selected and reviewed. The final reference list was defined based on the relevance of each paper to the scope of this review. Results: The available data showed that endocrine side effects are generally rare and with favorable outcome, being thyroid disorders the most common. Conversely, data on type 1 diabetes mellitus are rare; adrenal and pituitary events are even anecdotal. Finally, the available clinical studies suggest no impact on female reproductive system and on male and couple fertility. Conclusion: Overall, these data show that, after 2 years of COVID-19 vaccines, the endocrine system is not heavily threatened.