Subacute thyroiditis post viral vector vaccine for COVID-19.

Subacute thyroiditis is an inflammatory disorder of the thyroid gland that can occur after a viral illness or vaccination against certain infections. Subacute thyroiditis is a rare adverse effect that has been reported to occur after different types of SARS-CoV-2 vaccinations. Subacute thyroiditis post vaccination is relatively straightforward to manage, with some patients requiring non-steroidal anti-inflammatory drugs and beta-blockers, while more severe cases may require corticosteroid therapy. This adverse effect should not dissuade vaccination use at a population level. There are many postulated mechanisms for the development of subacute thyroiditis following vaccination including the presence of the ACE-2 receptor for SARS-CoV-2 on the thyroid gland, an inflammatory/immune response as is seen in COVID-19 infection itself and molecular mimicry between SARS-CoV-2 spike protein and healthy thyroid antigen.