One point that subverts the idea of this being caused by prior immunization is that the enzyme is IC1, requiring the phage particle, not functional on its own.
@Rumraket notes earlier that even if it was immunized, that doesn’t explain how the immune system searched a 10^77 space, as Axe/@Agauger would predict. Perhaps you could argues 10^15 or so, but we are very far from the ID prediction.
As @mercer notes, this is not the only paper we can go to. There are many many more. So we can work through the next paper after this is digested.
This seems to be a major problem for ID theory, which has relied on the correctness of Axe’s hypothesis. It seems this data invalidates the hypothesis. I am very interested to see @Agauger and @bjmiller’s response.