Hi R.,
You need to be very careful about vaccinations now with your child(ren) and yes all of them can and very likely should be fed Gluten Free - Casein Free (GF-CF). There is a very good site to go to with so much information on the 'diet' and how to get started, recipes, shopping, substitutes, what to look for with infractions, .....
www.tacanow.org GF-CF Diet is a pull down menu at the top.
While you are there, take a look at the Medical section, Vaccines. Our children are having sky rocketing rates of asthma, allergies, autism, add and with the rise in the number and types of vaccinations YOU need to do the research to see which ones and when they should be administered for EACH of your children. They are different and yet the same.
Never vaccinate a baby/child/adult when you are sick, have been on antibiotics, there has been a previous reaction to a vaccination to the child or family member, have allergies to eggs, wheat, yeast and it is best to not use Tylenol as it puts the immune system to bed for up to 48 hours and depletes the glutathione levels that are needed when an attack is made.
Hope this is not too much being thrown at you but it is important for you to know that there is a problem developing in your youngest and you need to be aware of it.
Regarding the diet, my daughter has to be very strict on it and I should be following it as well so I cook for the whole family gf-cf and sometimes add in something else for the boys.
You can always contact me about the diet. Good luck and the best way to keep you on course is to think of those ingredients as being opiates/drugs to your child. When they have that food, it converts it to a drug when it reaches the brain, which it does in a lot of kids on the autism /add spectrum. My daughter cannot have casein, gluten, soy, eggs, yeast, some beans, pineapple, cantelope and when she stays off of them, no asthma and behaviors are good (well, as good as they can be for a teenager). When she has had something on the list she becomes Mr. Hyde (dr. jeckell), split personality.
So go to www.tacanow.org and follow the 10 weeks to GF-CF. My family did it cold turkey so you decide what is best in your case.