Just so we’re clear, PE062* is not purifier. PE062 is an agent that we don’t get to see or interact with in game that kills the blob, and is not purifier. Purifier is a specific flavor of mutagen that just reverts you back to having human traits. PE062 is apparently one of the three ways to rid yourself of infestation of the blob.
*I previously referred to it as PE063, but it is actually PE062
As far as reproduction, any children would start life with the blob inside them, and it is extremely likely that the amount of blob would rise quickly because of how weak/non-existent the immune system of a fetus is. This makes it extraordinarily likely that the blob would reach critical mass and kill the baby (and possibly reanimate it but I really don’t want to think about that). As for mutations… I don’t really know. It says that it’s “just traits” and not full genome fuckery, but honestly who really knows what reproduction with a mutant would cause. If it causes anything, that something would almost certainly be an affront to all things holy in the world.