Are there different allergy shots depending on what breed of dog I'm allergic to?

[Incumbent]

I'm planning to get a dog within the next few months. I have mild allergic reactions to many dogs, and severe allergic reactions to a few breeds, so I plan to start getting allergy shots. My question is, are there different allergy serums for allergies to different breeds, or are all serums for dog dander the same? I need to know if I can start the allergy shots now before I know what breed of dog I will have, or if it would be better to know what breed I'll be getting so I can get the serum specifically for that breed's dander.