Certain pollens are the principal cause of seasonal allergy
(Image Credit: A.D.A.M. Inc.)
Life Science Space (June 6, 2008)--Streaming eyes, runny nose and endless sneezing? Help might be on the way in the form of a hay-fever vaccine that works faster and involves far fewer injections than existing treatment regimens.
Hay fever and some other allergies are caused by an overactive immune response to pollen. Conventional treatments consist of a series of pollen injections that gradually increase in strength, eventually training the immune system to ignore pollen. It is a long, drawn-out process, requiring at least 100 shots spread over up to five years.
Meanwhile two vaccines against ragweed allergy developed by Dynavax Technologies of Berkeley, California, and Curalogic of Copenhagen in Denmark, require fewer injections but were recently abandoned because they worked no better than placebos.
Now, a low-hassle hay fever vaccine, requiring just four injections over four weeks, has been shown to have some effect. Although it is not dramatic, Tom Holdich of Allergy Therapeutics in Worthing, UK, which developed the vaccine, points out that it is the only one of its kind that works. Neil Kao, an allergy physician based in Greenville, South Carolina, agrees: "The size of symptom relief is small, but the convenience is very high."
The company gave 1028 volunteers in Europe and North America either its vaccine - Pollinex Quattro - or a placebo just before the start of the 2007 pollen season. During the four "peak" weeks, symptoms were on average 13 per cent less severe in vaccine recipients. One-third of volunteers recorded their symptoms between May and September, and for them the effect appeared to be doubled. The company will present the results on 8 June at the European Academy of Allergology and Clinical Immunology meeting in Barcelona, Spain.
As well as pollen, Pollinex contains monophosphoryl lipid A (MPL), which "retunes" the immune system by damping down the usual "Th2" reaction to pollen and encouraging the milder Th1 response. The vaccine works in a short time because its pollen protein has been modified both to sneak past the body's antibodies, allowing large doses to be given from the start, and to lodge in tissue rather than going directly into the bloodstream, prolonging its effect on the immune system.
Allergy Therapeutics hopes to apply for approval in Europe next year. In the US, the Food and Drug Administration must first review the safety of MPL, which is also present in a cervical cancer vaccine made by GlaxoSmithKline.
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Source: New Scientist magazine, 05 June 2008, page 12
See also:
Allergy Therapeutics--
http://www.allergytherapeutics.com/POLLINEX%20Quattro%20.aspx
http://www.allergytherapeutics.com/G301%20results.aspx
PubMed--
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