CNN reports on a new blood test that measures levels of the protein p-tau217 shows remarkable accuracy in detecting Alzheimer’s disease, even before symptoms emerge. In a study of 786 people, the inexpensive and minimally-invasive screen was up to 97% accurate in identifying Alzheimer’s-related pathology in the brain compared to spinal fluid tests and brain scans. If approved for clinical use, this blood biomarker could allow for routine screening of adults over 50 and earlier interventions in high risk individuals, before significant decline sets in. With further validation, the test may usher in an era of accessible Alzheimer’s detection, guiding treatment and prevention to slow progression of the disease.