I'm not an MD, but I doubt a few injections of various types of blood would be enough to "vaccinate" against organ rejection. The exposure time of the infant's immune system to the foreign blood may not be long enough for the infant's immune system to regard it as familiar.

I'm not an MD either, but the report seemed to indicate an adaptive capability in infants that could be put to general good use beyond organ implantation. It seems to me it should be checked out.

I didn't mean to say it shouldn't be looked into, only that a small number of injections was unlikely to provide the desired adaptation of the immune system.

However, if you provided exposure to the proteins that signify blood type frequently and over a long period of time, you might be able to cause the desired result.

This would need lots and lots and LOTS of research. There are may be unforseen consequences of immunizing infants against tissue rejection. Specifically what, I can't say, that's the nature of "unforseen consequences."

The immune system controls tissue rejection and also is vital in prevention of cancer. Disabling the immune system might lead to a predisposition to cancer.

A baby's immune system is immature; that's why it doesn't do a very good job of fighting "non-self" antigens (and apparently allows transfusions of unmatched blood products).

Giving a baby "non-self" antigens in the form of unmatched blood will not prime the system to accept those antigens as "self". God forbid it worked that way, or our immune systems would also start to think other foreign antigens in our bodies (like ingested bacteria) were "self" as well.

What happens it that the baby is exposed to that particular "non-self" antigen (in the unmatched blood) early in life, so the next time he/she gets unmatched blood, the immune system will be able to say, "oh, I recognize this particular antigen--I've seen it before, and I know it's "non-self"! and mount an attack. Which is exactly what a healthy immune system is supposed to do!