Alex

Alex is the brother of the currently unnamed protagonist in "Cliche Vampire Story", the only information we're given on him is that he was in the hospital visited by the protagonist before the protagonist was turned into a vampire. He appears in this video, in the story part "The Start of Vamphood" where the protagonist is telling us about a visit with her brother, thought about by Anime Chara, deciding to name the brother Alex as it was a "cliche'd name for a boy".

Trivia
He was originally going to be a friend of the protagonist's, but that wouldn't have worked as the story is supposed to be about a girl with no friends that is a loner becoming a vampire.

He is in the hospital, But reasons aren't known yet.

He may have met a similar fate to the Protagonist of the story before the story started, Though that is unlikely as the protagonist quotes she is the only female vampire in her town, meaning there isn't a lot of vampires to bite Alex.

If Alex did infact meet a similar fate to the protagonist prior to the story, Alex is probably in the hospital as he is insane and is being sent to an insane asylum.