Med Student here so possibly wrong but... There is a well established link between oestrogen and increased blood coagulability. Whilst it is possible females a

Med Student here so possibly wrong but... There is a well established link between oestrogen and increased blood coagulability. Whilst it is possible females are more affected by the vaccine I suspect one factor is that their baseline coagulation risk increases their likelihood of thrombus due “reaction induced coagulability” compared to males.