Immune thrombocytopenia and COVID-19 vaccination: Outcomes and comparisons to prepandemic patients

Philip Young Ill Choi, Danny Hsu, Huyen Anh Tran, Chee Wee Tan, Anoop Enjeti, Vivien Mun Yee Chen, Eileen Merriman, Agnes S.M. Yong, Jock Simpson, Elizabeth Gardiner, Nicolas Cherbuin, Jennifer Curnow, Dominic Pepperell, Robert Bird

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2 Citations (Scopus)


Background: Immune thrombocytopenia (ITP) has been reported following COVID-19 vaccination. After index case fatalities, there was concern among patients both with and without a prior history of ITP in Australia. Objectives: To describe treatment outcomes of ITP after COVID-19 vaccination and compare relapsed vs historical pre-COVID-19 ITP cohorts. Methods: We collected ITP cases in Australia within 6 weeks of receiving any COVID-19 vaccination as part of primary vaccination (up to October 17, 2021). Second, we reviewed platelet charts in a historical ITP cohort to determine whether platelet variability was distinct from relapsed ITP after vaccination. Results: We report on 50 patients (37 de novo, 13 relapsed ITP) vaccinated from March 22, 2021, to October 17, 2021. Although there was 1 fatality, bleeding was otherwise mostly minor: (70% WHO bleeding grade <2). De novo ITP was more likely after AstraZeneca ChAdOx1 nCoV-19 (89%) than Pfizer BNT162b2 (11%). Most patients responded quickly (median, 4 days; complete response, 40 of 45 [89%]). In the historical cohort, only 6 of 47 patients exhibited platelet variability (>50% decrease and platelets <100 × 109/L), but median platelet nadir was significantly higher than vaccination relapse (27 vs 6 × 109/L, P =.005). Conclusion: ITP was more frequently reported after AstraZeneca ChAdOx1 nCoV-19 than Pfizer BNT162b2 vaccination. Standard ITP treatments remain highly effective for de novo and relapsed ITP (96%). Although thrombocytopenia can be severe after vaccination, bleeding is usually mild. Despite some sampling bias, our data do not support a change in treatment strategies for patients with ITP after vaccination.

Original languageEnglish
Article number100009
Number of pages13
JournalResearch and Practice in Thrombosis and Haemostasis
Issue number1
Publication statusPublished - Jan 2023
Externally publishedYes


  • BNT162 vaccine
  • ChAdOx1 nCov-19
  • COVID-19 vaccines
  • immune thrombocytopenia
  • treatment outcome
  • vaccination

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