Kittens are placed after they have completed a series of "kitten vaccines" as recommended by the AAFP.
My vet uses Ft. Dodge, killed vaccine, three in one.
Allergy Suffers, No animal is non-allergenic. Through the years, I have seen many people react favorably to Siberians. Those allergy folks that have mild reactions usually have the most success. There are certainly many things that an allergy sufferer can do to help their reactions to Siberians, such as, Hepa filters, bathing the cat, etc.
I do not grarantee any Siberian Cat to be hypo-allergenic. I suggest you test your allergies with Siberians. I am not a good test home because I have other breeds of cats in my home. I can send samples of fur and I can sometime arrange to meet you in your home or at a cat show. I may know someone near you that might be able to talk with you about allergic reactions and Siberians or even let you test with their Siberian.
However, allergies are very unpredictable. My concern is always the welfare of the kitten/cat. What would happen to the Siberian should you become allergic or your circumstances change. My cats are family members and I try to match the cat with a wonderful and loving home.