BCG vaccination mitigates tau pathology and restores cognitive function in PS19 mice.

BCG vaccination in PS19 tauopathy mice reduced hippocampal phospho-tau and microgliosis while preserving neuronal markers. Volumetric T2-MRI showed attenuated brain atrophy and increased glutamate-weighted chemical exchange saturation transfer MRI signals, with improved novel object recognition performance, body-weight maintenance and survival, and hippocampal disease-associated gene expression near healthy control levels.