ELI5, how come when you get an organ transplant, there’s a chance your body will reject it and your immune system will kill it. But when you get infected by a new disease, it’s difficult for your immune system to kill the disease.

Question

ELI5, how come when you get an organ transplant, there’s a chance your body will reject it and your immune system will kill it. But when you get infected by a new disease, it’s difficult for your immune system to kill the disease.

In: Biology

Answer 1

The virus/bacteria responsible for the disease have evolved for millions of years to survive and reproduce faster than the immune system can eliminate them.

The organ has evolved for millions of year to work with an immune system defending and not attacking it.

And the immune system has spent millions of years to attack anything that’s not supposed to be inside the body.