Biden tests positive for Covid-19 and will self-isolate in Delaware, White House says
www.nbcnews.com
The White House said Biden is heading to Delaware and will "continue to carry out all of his duties fully during that time."

I'm guessing it's how he's getting shuffled out, hence they just came up with a pretext earlier https://www.nytimes.com/2024/07/17/us/politics/biden-health-election-drop-out.html