PROS1 and COVID-19: Soon after, however, a report was published describing the case of a woman suffering from Moderna-COVID-19-vaccine-induced thrombocytopenia and with 10 ng/mL vaccine-induced S protein levels in plasma 10 days after vaccination [8], thus nearly 100 times higher than those reported previously [7], suggesting excessive vaccine-induced production of S protein as a determinant of vaccine toxicity.