Thrombocytopenia as an Emerging Adverse Event Associated with COVID-19/SARS-CoV2 Vaccination

This review includes data supporting thrombocytopenia as an emerging adverse event associated with SARS-CoV2 vaccination, analyzes the published case reports supporting an association with acquired Thrombotic Thrombocytopenic Purpura (aTTP), reviews the association of Thrombosis with Thrombocytopenia Syndrome (TTS) and Immune Thrombocytopenia Purpura (ITP), analyzes data from the U.S. Food and Drug Administration’s (FDA) Vaccine Adverse Event Reporting System (VAERS) database, provides guidance for clinicians caring for patients desiring vaccination but at potential risk of COVID-19 vaccination associated thrombocytopenia, and provides guidance for patients with a history of thrombocytopenia to better enable an informed decision regarding the choice of vaccination. Although the incidence of thrombocytopenia is sufficiently low to allow the continued use of SARS-CoV2 vaccines in patients with a history of thrombocytopenia, caution is advised. The burden of disease in reported patients was significant with death in 8.99% of patients developing thrombocytopenia after receiving the COVID-19 vaccine and 15.4% having a life-threatening event. The burden on the healthcare system includes 30.6% of reported patients developing thrombocytopenia after receiving the COVID-19 vaccine requiring an ED visit, 26.5% requiring an office visit, and 49.5% requiring hospitalization. Hospitalizations were significant with a median stay of 7.21 days. Patients desiring vaccination should be screened for prior thrombocytopenia and counseled on the risks/benefits of vaccination that are unique to their medical history. Patients with a history of thrombocytopenia may choose to receive vaccination but should be monitored for the development of thrombocytopenia during 0-90 days and possibly as long as nine months following their last dose of vaccination.