> Some kind of ability to have contagious antibodies might be an actual improvement but the fact that we don't see that in nature tells me it has downsides that

> Some kind of ability to have contagious antibodies might be an actual improvement but the fact that we don't see that in nature tells me it has downsides that are difficult to see. My biology education is a bit weak, but off the top of my head, autoimmunity being contagious sounds like a likely side-effect of contagious antibodies.