(Ramon Tomey) The messenger RNA (mRNA) vaccines developed to fight the Wuhan coronavirus may have caused at least 36 individuals to develop a rare blood disorder. Either Moderna’s mRNA-1273 jab or the Pfizer/BioNTech BNT162b2 vaccine may have caused thrombocytopenia – which affects blood clotting – in these individuals. Both vaccines had reported more than 90 percent efficacy rates and had received emergency use authorization in the U.S.