Individual changes in platelet count after both COVID-19 vaccinations in patients with ITP and in healthy controls. The absolute difference in platelet count is shown per individual in patients with ITP (red) and healthy controls (blue), absolute differences between baseline and 4 weeks after the second vaccination (A1-A2), between baseline and the second vaccination (B1- B2), and between the second vaccination and 4 weeks after the second vaccination (C1-C2). Every bar represents 1 subject. A positive change in absolute platelet count means an increase in platelet count after COVID-19 vaccination, whereas a negative change represents a decrease. *Subject received rescue medication during the study period.