Yes, aware of it, but can you really stop kids from touching peanut butter by accident?
If your kid is allergic, you have to teach it to be extremely careful very early, e.g. not to touch or accept food from other kids. Banning peanuts from schools is not really helpful. If anything, it teaches them that it's okay to be careless.
As @Yamikuronue said, in extreme cases, you should make the teachers and the rest of the class aware. I'd say that's common sense.
Note that I'm not completely uneducated on the topic. My cousin has a severe nut allergy. She survived school just fine, though, and the rest of the kids were still able to enjoy their Nutella sandwiches.