COVID-19 mRNA vaccine may trigger subacute thyroiditis.

Area of Science:

• Endocrinology
• Immunology
• Vaccinology

Background:

• Subacute thyroiditis is typically viral-induced and painful.
• Rare instances of subacute thyroiditis have been linked to viral vaccinations.
• The COVID-19 mRNA vaccine (Pfizer/BioNTech®) is a novel intervention with potential side effects under investigation.

Purpose of the Study:

• To report and characterize cases of subacute thyroiditis following COVID-19 mRNA vaccination.
• To describe the clinical, laboratory, and imaging findings associated with this vaccine-induced condition.
• To raise awareness among clinicians regarding this potential adverse event.

Main Methods:

• Case series reporting on five patients.
• Clinical data collection including symptoms, onset, and duration.
• Laboratory tests for thyroid function and acute-phase reactants.
• Imaging studies (e.g., ultrasound) to assess thyroid involvement.

Main Results:

• Five cases of subacute thyroiditis occurred after COVID-19 mRNA vaccine (Pfizer/BioNTech®) administration.
• Symptoms included fever, neck pain, weakness, and tremor, appearing days post-vaccination.
• Thyroiditis presentation ranged from focal to diffuse bilateral involvement.
• Elevated acute-phase reactants were observed, correlating with disease extent.
• Cases responded well to non-steroidal anti-inflammatory drugs.

Conclusions:

• Subacute thyroiditis is a potential, albeit rare, adverse effect of the COVID-19 mRNA vaccine (Pfizer/BioNTech®).
• Clinical presentation mirrors classic subacute thyroiditis, necessitating physician awareness.
• Prompt diagnosis and treatment with anti-inflammatory agents are effective.