A "vaccine" for ragweed sufferers? As I was taking my kids to soccer practice, I was listening to the latest medical breakthrough on NPR. Intrigued, I retrieved my latest edition of the New England Journal of Medicine and began to read.

First, Allergies 101. Immunotherapy has been around since 1911, pursuing the treatment of allergies. What is an allergic reaction to ragweed? When a person has a runny nose and eyes, specifically every August through September, he/she may have ragweed allergies. Usually medications such as nasal steroids, antihistamines or leukotriene inhibitors will be tried first, but if symptoms persist, an allergist may enter your life. The doctor will test your immune system to see what it reacts to by either multiple skin tests (preferred by allergists) or a blood test (possibly preferred by patients).

Either the skin test or the RAST blood test is done to detect specific immunoglobin E (IgE) sensitivities. This indicates an allergy, or your body's immunological response to an allergen. The skin test is performed by placing an extract of the allergen on the skin by pricking the skin. A red elevated skin response, or a "wheal-and-flare" response, is considered positive (your body's immune system reacting to the allergen). If you have allergies to ragweed and a positive skin test for ragweed, then you are all set for allergy shots.

Allergy shots, or desensitization of allergens involves injecting allergen extracts at increasing concentrations over a period of time, possibly years. There are a few problems associated with this approach. The shots may themselves induce an allergic reaction which at times may be serious, and because it takes a lot of shots to desensitize (2 injections a week for 10-12 weeks), many people don't complete all the shots. Although it works, 3-5 years is a long time to wait for results (that is 21 to 35 dog years!)

Now that you are all experts on the subject, I'll tell you about this exciting medical breakthrough. In a small study, the authors from Johns Hopkins took ragweed pollen and attached it to an "immunostimulatory sequence" of DNA. Injected 6 times before ragweed season, this "vaccine" decreased the body's allergic response not only for that ragweed season, but for the next season, too! Unlike standard shots having side effects in 1-20% , no adverse reactions were noted . Although it was a small study of only 25 patients this may be a very exciting finding as allergy vaccines may offer a shorter, safer, and longer lasting treatment option to allergy shots.

We are entering an era in medical research which will be very molecular and genetically oriented. Although complicated and at times confusing, it will affect the root of disease and eventually be safer and more effective than the therapies we have today. I am involved in several research projects at Mary Washington Hospital and I feel very strongly it is important to support medical research to allow us and our children a better selection of medicines and therapies to live happier and healthier lives.

Next month: Food allergies!

Dr. Jeffrey Rehm, father of three, is a pulmonologist at both Mary Washington Hospital and
521 Park Hill Drive. Phone is (540)899-1615.