I’m late to this disturbing study of 301 Thai adolescents aged 13 to 18, who were monitored for cardiac symptoms following Dose 2 of Pfizer. Nearly a third reported effects of some kind, and 2.33% of the participants (3.5% of the males) exhibited biomarkers indicating damaged heart muscle. The rates are substantially higher than those found in prior studies, probably because “the study protocol … required determining baseline troponin-T, CK-MB, ECG and echocardiography before vaccination” (p. 11). In other words, the authors established individual baselines for each patient to better detect subtler anomalies.