I get them.. they work! To start you have to go twice a week minimum 6 months to 1 year. Then you can go once a week for another year. Then once a month for the next 1-2 years. Then you can stop for a good few years. But some people have to go back to taking shots others never need to. As for when you will feel better maybe 6 months. But if you stop the shots the allergy could come back fast, so you got to keep doing it for a long time to make sure it doesn't come back. If you are going to go through all that you should do a full allergy testing. It takes the same amount of energy to cure 1 allergy as it does 50 allergies. Might as well make the most of your injections.
If cat is the only thing you are allergic to, might be easier to just try a few different antihistamines. One might work better than another.
Cat allergen, the allergy causing material from cats, is not cat hair, but rather a protein present in the dander and saliva of cats. These allergens become airborne as microscopic particles, which when inhaled into the nose or lungs can produce allergic symptoms.
Allergy desensitization shots or immunotherapy are an obvious and very effective way to work around a cat allergy. Immunotherapy will gradually make a person more and more resistant to the allergens. The goal of immunotherapy is to increase the tolerance 10 times. This is one of the most effective treatments because it treats the cause and doesn’t just hide the symptoms.
In addition to the immunotherapy,you can go in for various measures in the environment which can reduce your chances of allergy to cats. You should not allow cats in your bedroom or the area where you spend most of your time and you can also try spraying areas where your dogs spend their time (carpets, sofas) with an anti allergen spray.
Use reputable allergy avoidance products throughout your home. Wash your hands after having contact with your pet. Keep pets out of the bedroom and avoid using carpeting, draperies and upholstered furniture in your home since allergens will collect there. Also wash and brush your pet each week. Replace carpets with linoleum or wood. Vacuum with a (HEPA filter vacuum cleaner )soft furniture and curtains as well as floor Wash carpets and upholstery with special cleaners, such as benzyl benzoate or tannic acid spray. Wash all bedding in hot water (hotter than 130°F) every 7 to 10 days. Don't use mattress pads. Cover mattress and pillows with plastic covers. Lower the humidity in your home.You can also use air filteration systems in your homes.
Hope I have provided you with sufficient information.In case you have additional doubts,then pls post us.
Take care and regards.