First-dose ChAdOx1 and BNT162b2 COVID-19 vaccines and thrombocytopenic, thromboembolic and hemorrhagic events in Scotland.Simpson CR, Shi T, Vasileiou E, Katikireddi SV, Kerr S, Moore E, McCowan C, Agrawal U, Shah SA, Ritchie LD, Murray J, Pan J, Bradley DT, Stock SJ, Wood R, Chuter A, Beggs J, Stagg HR, Joy M, Tsang RSM, de Lusignan S, Hobbs R, Lyons RA, Torabi F, Bedston S, O'Leary M, Akbari A, McMenamin J, Robertson C, Sheikh A.