Book about an ex soldier who has secured a monastery high on some cliffs (like the one in Greece) and is charging rich parents to buy tickets to save their kids, who are generally misfits, during a pandemic. It turns out the site is not as secure as one of the kids stumbles across an old monk. He turns out to be a carrier and the disease starts running rampant through the kids.

Help me please!! I got this book from my public library years ago and cannot remember the name. I have searched their database with keywords.

Have you asked reference librarians (in the young people's department too) for help? They read books and may know instantly which book you are talking about. And they are experts at keyword searches, plus have WorldCat and genre databases to search. You might want to call more than one library as you search.

Enclave by Kit Reed