GILLIAN SHEPHERD, MD: Let's say you're allergic to cat. And you're allergic to this amount of cat. Allergy shots mean or allergy vaccine therapy is that you get a shot of the cat, weekly, going up like this once a week until you get up to the top dose. When you get to the top does, the amount you're allergic to-you then switch and you get a shot once a month to keep the allergy turned off. That type of treatment is very effective. What is does is it sort of puts the lid on the over-reactive immune system. Stops it from going crazy every time it sees cat. And as a result, somebody who is on allergy shots to cat, they're allergy system sees cat and just doesn't react.
ANNOUNCER: The length of time that a patient will get allergy shots varies.
GILLIAN SHEPHERD, MD: Most people who do get allergy shots, if they get them for pollens, that they're exposed to, or dust mites on a regular basis, will normally do it for anywhere from three to five years. It's not a forever treatment. It is a forever treatment for the cat owners as long as they own the cat.
ANNOUNCER: Many allergy sufferers are good candidates for immunotherapy.
MARJORIE SLANKARD, MD: The candidates for immunotherapy would be someone with allergic rhinitis and or allergic conjunctivitis or allergic asthma who, is not doing ideally with trying to control their environment in some limited medications.
ANNOUNCER: But there are some allergy sufferers who should not receive allergy shots.
BETH CORN, MD: Very severe asthmatics would probably not be candidates for allergy shots. The most common side effect is a local reaction to the allergy shot. So if someone receives an allergy shot in their arm, chances are that if they're going to have a reaction they might get a red raised reaction.