This is the kind ofBig Brothertwist that nobody wanted to see.

She will instead be replaced by an alternate, Claire Rehfuss.

Rehfuss is a 25-year-old AI engineer from New York City.

Big Brother 23

Claire Rehfuss and Christie Valdiserri on ‘Big Brother’.Cliff Lipson/CBS; CBS

Valdiserri addressedBig Brotherfans with the news in a video posted on Twitter.

“Hey, guys,” Valdiserri begins in the video.

I have the vaccine and I’ve been following all the guidelines up to this point.

I have absolutely no symptoms.

I feel perfectly fine.