I haven't read the book (inclined to look for it now) but, was sort of wondering if my serotonin metabolism disorder is enough to deter zombies. If not, they're clearly discriminating against the mentally ill (which would come as no surprise really). Failing that, what about hypermobility syndrome and borderline asthma ? I have a wonky BRCA gene too. Nearly all of us have dormant herpes...why doesn't that count?