It suggests concomitant COVID-19 infection could amplify pre-existing dementia in at least two ways: (1) by modulating the expression of proteins that may worsen AD; (2) stressing the already dysfunctional neurons especially in areas with abundant hyperphosphorylated tau protein and/or β-amyloid-42; (3) potentially increasing neuroinflammation (16). Here, MAPT is linked to Alzheimer disease.