Authors: Eun‐Ju Lee, ¹ Douglas B. Cines, ² Terry Gernsheimer, ³ Craig Kessler, ⁴ Marc Michel, ⁵ Michael D. Tarantino, ⁶ John W. Semple, ⁷ Donald M. Arnold, ⁸ Bertrand Godeau, ⁵ Michele P. Lambert, ^{9 , 10} and James B. Bussel ¹¹

Cases of apparent secondary immune thrombocytopenia (ITP) after SARS‐CoV‐2 vaccination with both the Pfizer and Moderna versions have been reported and reached public attention. Public alarm was heightened following the death of the first identified patient from an intracranial hemorrhage, which was reported on the Internet, then in USA Today 1 and then in The New York Times. 2 Described below, we have collected a series of cases of very low platelet counts occurring within 2 weeks of vaccination in order to enhance our understanding of the possible relationship, if any, between SARS‐CoV‐2 vaccination and development of ITP with implications for surveillance and management.

Twenty case reports of patients with thrombocytopenia following vaccination, 17 without pre‐existing thrombocytopenia and 14 with reported bleeding symptoms prior to hospitalization were identified upon review of data available from the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), agencies of the U.S. Department of Health and Human Services (HHS) Vaccine Adverse Events Reporting System (VAERS), published reports, 3 , 4 and via direct communication with patients and treating providers. These cases were investigated as suspicious for new onset, post‐vaccination secondary ITP; we could not exclude exacerbation of clinically undetected ITP. Search terms relating to “decreased platelet count”, “immune thrombocytopenia”, “hemorrhage”, “petechiae”, and “contusion” were utilized to identify cases reported in VAERS.

The reports describing 19 of 20 patients included age (range 22–73 years old; median 41 years) and gender (11 females and 8 males). Nine received the Pfizer vaccine and 11 received the Moderna vaccine. All 20 patients were hospitalized and most patients presented with petechiae, bruising or mucosal bleeding (gingival, vaginal, epistaxis) with onset of symptoms between 1–23 days (median 5 days) post vaccination. Platelet counts at presentation were available for all 20 cases with the majority being at or below 10 × 10⁹/L (range 1–36 × 10⁹/L; median 2 × 10⁹/L).

For More Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8014568/