As MSNBC reports (I did not read the original article in Lancet yet), experimental vaccine against Alzheimer’s was successfully developed and tried on a number of Alzheimer’s patients, most of which were followed till their death up to 6 years. Vaccine was designed to clear the brain from a-beta plaques. It did just that as post-mortem analysis showed. The problem is … those patients did not get any less dementia nor lived any longer. The most obvious conclusion – plaques do not cause Alzheimer’s or dementia, they are either protective or irrelevant for patho-physiology of the disease.
I am thinking that counting plaques as the measure of Alzheimer’s severity in mice is very misleading at this point, and might get exponentially more complicated to publish.