Please don't cause yourself stress by worrying about your son having pertussis - even if he was vaccinated he could still contract the disease. Simply put there are variations of the disease that the vaccine doesn't cover. I was vaccinated for pertussis as a child and still contracted the disease. Also, thank yourself that you didn't vaccinate your child. Because you didn't vaccinate your child, you can rest assured that his immune system isn't supressed and is working in proper order to fight this disease.
A close friend of mine dealt with her son having pertussis - it is a long battle, but it does end and there are things you can do to make it easier.
I suggest the following:
--> Warm steamy baths with eucalyptus oil dropped in the water (10 to 20 drops to a bath)
--> Mega vitamin C (up to bowel tolerance then just taper off a little)
--> Lobelia, a calming herb that calms the mind and body and also treats many respitory problems
--> Pleurisy Root, which is an effective an effective diaphoretic and anti-spasmodic it also assists in expetoration. It is used to treat various respitory problems.
--> I would also give either grapefruit seed extract or coloidal silver in theraputic doses three or four times daily.
--> Also give no sugar and no white flour food products! No processed pre-packaged foods. They just supress the immune system and that is not what you want at this time.
Make a soup.
Start with chicken broth (organic only) If you don't have an organic/free range chicken you can buy pure organic chicken broth at a grocery or health food store.
Once you have your broth add 2-3 cups into a 6 quart pot. Then add 2-3 cups of water. Add 4-5 onions, a whole bulb sectioned and pressed through a garlic press, one Celery heart and 5 carrots (chopped) simmer on the stove for two hours. To season use cayenne pepper (however much you think your son can handle) and cumin (just a dash) Sea Salt and ground. If you have whole wheat or spelt noodles you can add a few to give the soup some more texture. If you have poultry seasoning, add a dash to taste.
My secret is you just keep adding your ingredients until it tastes right and satisfies your palate. That is why my ingredient instructions are kind of loose.
Also, be sure your ingredients are pure and organic foods.