Hopefully you don't need surgery, but things happen and you might need a transfusion. Getting someone else's blood is always a little risky. And now you don't know if you're getting blood from someone who has been vaccinated. Perhaps you didn't want the jab, but in the event of a medical emergency, who knows what you'll be getting.
The American Red Cross reports that 20% of donated blood has COVID-19 antibodies
I think you can ask for Plasm only. I think that is what Jehovah's Witness ask for instead of a full blood transfusion. But I could be dead wrong.
I grew up a Jehovah's witness, can confirm that they consider using plasma only on a "basis of conscience" because the underlying command is to abstain from blood from the Old Testament. Done take it to the most fundamental and refuse all transfusion