Good question! It looks they need convalescent plasma from COVID-19 survivors. For vaccine recipients to be eligible, FDA says they must have had symptoms of COVID-19 and a positive test result from an FDA-approved, -cleared or -authorized diagnostic; received the vaccine after being diagnosed with COVID-19; and are within six months of complete resolution of COVID-19 symptoms.
FDA explains that the criteria are โto ensure the COVID-19 convalescent plasma collected from Donors contains sufficient antibodies directly related to their immune response to COVID-19 infection.โ
You may still be able to donate regular plasma as there are other needs for that as well.