You've got two headers. first you say its a high school, then you say its a class room
just INT. HIGH SCHOOL CLASSROOM
i didnt know the gender of the teacher til halfway through the story
i didnt know if the teacher sneezed or if a kid sneezed until someone said bless you
" Frantically searching, he waves down someone in the hall. As he approaches them, the body hits the floor. They are gasping for air. "
the body? no "body" has been described. I assume you mean "their body" ?
you later say HALLWAY and CLASSROOM but you've abandoned all structure.. it should say INT. HALLWAY, etc
make it a real heading. keep it consistent.
My immediate reaction to all the students sneezing and coughing was that they were messing with the teacher.
Maybe if it was the teachers very first day or if they were a sub or something it would be more believable that the teacher was had.
Okay... I read it. I like it! Especially if this is something you're going to shoot on your own. I went ahead and wrote up some yellow sticky notes on the PDF but basically... If you're just shooting this yourself? Not much of this matters. If however, you're aspiring to eventually learn how to be a screenwriter? The notes should help...