On Dec. 21, 2000, Dr. Peter St George-Hyslop developed a vaccine that prevented Alzheimer’s disease in mice. The vaccine induced an immune response specifically against beta-amyloid (the protein that makes up senile plaques in Alzheimer’s) and has been shown to reduce and prevent plaque formation in mice.

The mouse model was genetically engineered to mimic Alzheimer’s, and after immunisation it was shown that the number of beta-amyloid plaques in the brains of these animals was significantly reduced. The researchers did not at that time look for any effects on cognition. The study was published in Nature.