There is a specific issue in Alzheimer's that is degenerative. PCS is not similar. The article says : "When Wyss-Coray’s team injected young human blood into old mice he says they saw “astounding effects”. Cross species transfusion sounds odd. It could be that human blood is the difference. They do not say what happens when they transfuse middle age human blood in mice.

Keep in mind that there have been many studies of therapies, drugs, etc that show improvement but those improvements are lost within weeks of ending the treatment/drug. I can't imagine needing a 2 unit blood transfusion ever 6 weeks to keep the improvement.

Will they stick a sticker on your forehead that says: Next transfusion due in 6 weeks or 1500 miles, whichever comes first ?

Many of these studies are really designed to identify a difference then they try to find a patentable drug that can cause the same effect.

Blood doping has been going on for decades. It is an expensive treatment.