[mxkopy]

https://en.wikipedia.org/wiki/Spleen

"The spleen plays very important roles in regard to red blood cells (erythrocytes) and the immune system. It removes old red blood cells and holds a reserve of blood, which can be valuable in case of hemorrhagic shock, and also recycles iron."

[viraptor]

Yes, but what does that have to do with the context here? (I.e. changes triggered by vaccination)