SJO, I can't help but to weigh in on this topic because I strongly relate to your concerns for your son. I have two daughters with CF (now 19 and 13 years old). For years, one or both get colds/respiratory viruses every Fall from school (or the store ... or friends ... or whatever), and those colds have many times led to CF exacerbations and hospitalizations (please know that my girls have had many hospitalizations and a cold won't necessarily cause your son to get that sick). My experience with trying to improve the classroom health environment (in both public and private schools, btw) was spotty at best. I agree that it would help a lot for your family to get flu shots and for your son to learn to wash hands/use sanitizing wipes/gel before meals, keep hands off face, etc., but you can also ask your son's teachers to move him away from kids who have an active cough, runny nose (not to move the sick kid ... political correctness and all). Protection from droplet transmission (coughing/sneezing) is a minimum of 3 feet away.
The reality of even this request is that noticing sick kids is not on most teachers' radar, even when they say they will keep an eye out for it, because they really don't understand CF. A great resource is CFRI's "CF in the Classroom" booklet that you can order, get from your CF Care Center, or better yet download the PDF and print out for the school. For me, sitting down with the teachers to explain how CF affects your child and what they can do to help seemed to sink in better with the teachers than a note. Still, they are all very busy and snotty-nosed kids and coughing are so routine that teachers don't notice what is alarming to us CF moms
. As they got older, my girls would sometimes discretely ask to be moved if needed, learning to advocate for themselves.
Based on how comfortable you and your child are, I highly recommend that you go into the classroom and talk to the kids. I did this when my younger daughter started a new school in the 3rd grade. I created a short talk that involved the class. We practiced saying "65 Roses" so they knew how to say Cystic Fibrosis; I covered that CF is: something my daughter was born with; they couldn't catch it (very important); it won't go away/can't be fixed yet (but there are great medicines she can take that help a lot); etc. Told them she might have to go into the hospital sometimes and what that's like (I kept this very light). The best part was discussing what they could all do to "help" my daughter—stay away if you're sick; cough into your elbow; wash, wash, WASH! etc., but mostly to be her friend and to pray for her. I also went into my older daughter's high school class and had a more age-appropriate conversation with them, but that's a looooong way away for you!
The bottom line for me is, as much as I (still) want to put my kids in a protective bubble, I can't, and I'd rather that they are out in the world doing life as normally as possible. I think most people do care and want to help if they understand, but that understanding needs to include the fact that my daughters (and your son) are still normal kids who do normal things and have normal wishes and dreams ... they just need a little more help with CF.
Best to you as you advocate for your son. You're a great mom!
P.S. if you want to know more about the class discussion I had, PM me. I might still have the materials I used.