Clinical studies have shown that a proper course of treatment with allergy shots can result in significant relief in as little as 3 months, but a longer duration of treatment is generally required to develop a tolerance to the allergen (in this case, cats). In some people, allergy shots that are are maintained for 3-5 years appears to offer long-term relief. In fact, allergy shots are the only allergy treatment available that has the potential to cure your allergy since it targets the basic allergic mechanism of your disease. Most medications that you are familiar with (prescription or over the counter) only target the symptoms and thus provide temporary relief (claritin, zyrtec, benadryl, nasonex, etc). When you suspend treatment with these medications your allergic reactions are likely to return.

An important question to ask your allergist is whether the maintenance dose being prescribed in your shot(s) is in line with what has been shown to be effective in clinical studies. Several large organizations of leading allergists have endorsed dosing guidelines for immnuotherapy for common allergens like cat hair. Your allergist should be following these guidelines to help ensure you are receiving the most effective treatment possible.

Good luck!