We were most concerned about my son because he had basically lived on steroids and nebulizers since the age of 1 1/2. He had severe asthma, a peanut allergy, and allergies to pets.
But we were determined to make it work. Here is the plan we came up with: Living with a cat when you have allergies. The first few weeks were challenging. My husband and son both had reactions. They took antihistamines for a few days.
Then we tapered off the antihistamines and eventually things changed. Sort of. Today, my husband is still allergic to our cat, but he can live in our home and has no issues unless he spends a long time petting or holding her. If he visits homes that have non-siberian cats, he immediately gets red eyes and sneezy.
My son is no longer allergic to her at all. He has no symptoms and actually outgrew his asthma and peanut allergy. He is also less sensitive to other animals (though he does get red eyes and a "closed throat" when we visit grandparents that have 3 little dogs.)
When we have guests over, even allergic ones, they have no issues with our cat. Most allergic visitors avoid her, but she lives in every room of the house and her fur and dander is....everywhere. I have also eased up on the vacuuming. It may have helped in the beginning, but it's no longer necessary.
If I could pin point what helped the most in ridding my son of his allergy, I would guess the following:
1. Omega 3 vitamins
2. A decrease in processed foods consumed
3. Age - growing larger lungs etc
4. Desensitization through exposure (through the cat and through repeated peanut exposure with the intent to desensitize)
5. Siberian breed having a lower FelD1 levels
In the end, I would say that Siberian cats are LESS allergenic but probably not NON allergenic. Keep that in mind if you are considering bringing a cat home.