A study by Ghent University and the Flemish Institute of Biotechnology (VIB) reported that repeated mild coronavirus infections caused changes in the brains of mice. The researchers observed fewer connections between nerve cells and, in mice predisposed to Alzheimer’s disease, more harmful protein accumulations.

The findings indicate a possible link between mild infections and processes associated with Alzheimer’s disease, particularly in brains that are already vulnerable. The study did not report findings in humans.