In the past three decades, more than 100 papers have described correlations between the presence of HSV–1 and the risk of Alzheimer’s. Ruth Itzhaki from the University of Manchester notes that “hostility or derision occurred with most of my papers on this topic, and many people simply ignored them.” But evidence continues to grow. Most recently, Ben Readhead and his colleagues at the Icahn School of Medicine at Mount Sinai showed that two herpes viruses, HHV–6A and HHV–7, were more common in the brains of Alzheimer’s patients than in those of healthy people. The team confirmed this in three separate groups of patients. And they found that the more abundant the viruses, the worse the patients’ symptoms.