Platelet counts of patients with ITP and healthy controls after COVID-19 vaccination. (A) Platelet counts of patients with ITP and healthy controls over the entire study period. Platelet counts are median ± IQR. No significant difference in platelet count over time was observed between the 2 groups. (B) Platelet counts for patients with ITP grouped by baseline platelet count. Absolute platelet counts are median ± IQR.