Bone Marrow Suppression Secondary to the COVID-19 Booster Vaccine: A Case Report.

As of September 2021, SARS-CoV-2 booster shots became widely available in the US to ensure continued protection against the virus. A temporal relationship has been previously reported between the first or second dose of the COVID-19 vaccine and the development of thrombocytopenia. However, adverse events related to the third COVID-19 vaccine are still being reported and studied. We report a 74-year-old male who developed bone marrow suppression and pancytopenia recorded seven days after receiving the Pfizer SARS-CoV-2 vaccine. During his hospital stay, the patient's hemoglobin, white blood cell, and platelet levels continued to trend downwards. However, all three levels showed improvement one week after discharge without robust intervention. Global vaccination is of utmost importance, as is understanding and documenting post-vaccination reactions including bone marrow suppression. Prompt evaluation and patient education are imperative to improve patient outcomes and combat hesitancy against vaccine administration.