The authors advise (pp. 109-110), how the blood donor services should discard the first 50ml of an individual's blood, as it contains information about that particular person's bodily disorder(s), like a "concentrated charge". That is why the same amount injected back to that same person, is so beneficial in a "homeopathic" fashion.
Taking the above into consideration it makes sense, when this strategic "first blood" is given to a different person, with diffent disorders, it might possibly have some slight disadvantageous effects for him or her.
That's interesting and it makes sense to me how there could be homeopathic-like elements in the blood, however do the authors explain why a second drawing of blood would not be as 'concentrated'? It would seem to me that the information in the blood would be pretty uniform.