https://www.mercurynews.com/2022/02/07/what-does-covid-19-do-to-your-brain/

Even after the SARS CoV-2 virus has been subdued, the immune system can’t calm down.

That is the current theory about what’s behind the strange, lingering and debilitating neurological symptoms of some COVID-19 patients, such as the commonly reported “brain fog,” according to a recent paper in the journal Science.