Thyroiditis after COVID vaccine


Top news in Healthmagazine | covid 19 | Skin Health | Treatment | Disease | Natural Beauty


Thyroiditis after COVID vaccine

Stem cells and healthiness

Subacute thyroiditis following immunization is a rare form of thyrotoxicosis. As the globe embarks on its greatest immunization campaign to date in an effort to protect the public from COVID-19 infections, an increasing number of unusual post-vaccination adverse effects are being reported.

Severe thyroid swelling after receiving the second dosage of the COVID-19

We present a case of a middle-aged lady who developed severe thyroid swelling after receiving the second dosage of the COVID-19 mRNA vaccine BNT162b2 (Pfizer–BioNTech), with clinical, biochemical, and imaging findings consistent with destructive post-vaccination thyrotoxicosis. For the self-limiting event, just symptomatic treatment was necessary.

It should not prevent individuals from being vaccinated

Thyroiditis is usually mild and self-limiting, thus this observation should not prevent individuals from being vaccinated, as COVID-19 infection has a far higher morbidity and death risk than thyroiditis.


Subacute thyroiditis (SAT) following immunization is a rare form of thyrotoxicosis. Rarer adverse effects are being reported as the world’s greatest immunization program continues. We provide an intriguing case of thyrotoxicosis after COVID-19 immunization, including its clinical history, diagnostic difficulty, and therapy.

Case study presentation

A middle-aged lady reported with a history of fast onset painful thyroid gland enlargement and thyrotoxicosis symptoms such as poor sleep, increasing night sweats, hyperdefaecation, and weight loss. Her symptoms began two weeks after her second dosage of the COVID-19 mRNA vaccine BNT162b2. The patient had no major medical history and was not using any regularly prescribed drugs. There was no previous usage of lithium, amiodarone, or interferon.


Initial biochemical tests revealed thyrotoxicosis, with normal anti-thyroid peroxidase (TPO) and thyroid stimulating hormone (TSH) receptor antibody levels. During the thyrotoxic phase, technetium (Tc-99m) pertechnetate thyroid scintigraphy revealed limited isotope absorption, consistent with destructive thyroiditis.

Symptoms vanished in 6 weeks

She had no therapy other than a brief course of nonsteroidal anti-inflammatory medication, and her symptoms vanished in 6 weeks; her thyroid function returned to normal in 8 weeks.

Diagnosis differencing

While Graves’ disease can cause transitory hyperthyroidism, the clinical presentation, normal thyroid autoantibodies, and scintigraphy results all pointed to subacute destructive thyroiditis.

The outcome and the follow-up

For pain alleviation, our patient was treated conservatively with a course of nonsteroidal anti-inflammatory medications (NSAIDs). Because her thyrotoxicosis symptoms disappeared quickly, she did not require any antithyroid or beta-blocker medication. At her three-month check-up, she was still clinically and biochemically euthyroid.


SAT, also known by other names, is widely known for causing follicular destruction and the fast release of preformed thyroid hormones. If a potential triggering event can be determined, it is most usually a viral upper respiratory tract infection 2–3 weeks before the beginning of thyroid symptoms.

Influenza immunization

However, there have been reported examples of SAT developing soon after receiving an influenza immunization. The actual pathophysiology of vaccination-associated SAT is unknown. Some authors attribute it to the adjuvant, which causes autoimmune/inflammatory syndrome induced by adjuvants (ASIA), while others speculate that the vaccine core component may cause either direct injury or share the same epitope, resulting in antibody cross-reaction between the antigen in the vaccine and thyroid follicular cells.

Antibody against the SAR-CoV-2

Because of the number of angiotensin-converting enzyme-2 receptors expressed on the surface of thyroid follicular cells, the SARS-CoV-2 virus obtains access into several endocrine organs, including thyroid follicular cells.  Studies with a human IgG1 monoclonal antibody against the SAR-CoV-2 spike protein revealed cross-reactivity with TPO, and other follicular cellular components.

Thyroid impairment

Thyroid impairment has been seen in almost one-third of all COVID-19 infections where thyroid function has been assessed.  However, no notable frequency of thyroid problems has been documented in studies conducted during the development of vaccines against the SARS-CoV-2 virus. This might be because the patient numbers in these studies are too small to detect unusual adverse effects.

Antigen component

There have only been two additional instances of post-vaccination thyrotoxicosis to our knowledge, one following the Pfizer mRNA vaccine and the other following CoronaVac, an inactivated whole-cell vaccine. At this point, it is impossible to say whether the immune response is primarily caused by the antigen component or the adjuvant.

TSH levels

The diagnosis is mostly clinical, with high thyroid hormone levels and suppressed TSH levels. Low isotope uptake on thyroid scintigraphy, as well as normal TPO and TSH receptor antibody levels, can help rule out other prevalent causes of hyperthyroidism. In cases where availability to these tests is limited, a lower T3 to T4 ratio favors destructive thyroiditis over Graves’ thyrotoxicosis.

Comment here