Fig. 3From: Incidence of anti-platelet factor4/polyanionic antibodies, thrombocytopenia, and thrombosis after COVID-19 vaccination with ChAdOx1 nCoV-19 in ThaisOptical density of 14 samples with positive and 704 samples with negative anti-PF4/polyanionic antibodies at baseline (before vaccination). Horizontal lines in the positive and negative sera column represent mean OD. Dot line represents the positive cutoff OD value of 0.3Back to article page