Abstract

Since December 2019 and the global epidemic of COVID-19 different countries have focused on vaccines, and one of the inactivated produced vaccines was the Sinopharm COVID-19 vaccine. Some side effects of this vaccine were reported previously, including pain at the vaccination site, fatigue, lethargy, headache, and tenderness, which were more prevalent among individuals <49 years old. Herein, we reported two patients aged 45 and 51 years old. Both patients have different signs and symptoms after receiving the second dose of the vaccine. None had a history of chronic disease. On examination and following labs and other diagnostic investigations, we found megaloblastic anemia due to atrophic gastritis and low intrinsic factor. These cases showed an autoimmune side effect of the Sinopharm COVID-19 vaccine that was previously reported with an exact mechanism but other features called Covid Arm, Guillain-Barré syndrome, and thrombocytopenia. The mechanism of this reaction is unclear yet. © 2023 Tehran University of Medical Sciences.