Antihistamines help some people achieve relief from their symptoms, including runny or stuffy noses, sneezing, and itchy eyes, nose and throat. But when these medications don't work, allergy shots are the next line of treatment.
Allergy vaccines are highly effective but have certain drawbacks, allergists say, including the number of shots required to build up an immune response.
"It takes between six and 18 months of weekly injections to reach the maximum effect, so people are coming in every week, and they get an injection," Howland explained.
In addition, it's recommended that patients wait in their doctor's office 30 minutes after each injection to be monitored for any adverse reactions that may occur.
The new wave of investigational vaccines have been tweaked to be more effective in fewer doses and to reduce the incidence of immediate side effects.
Early results look promising.
Howland and his colleagues, for example, studied different doses of a ragweed extract and their effect on antibodies in the bloodstream. People with allergies produce an antibody called immunoglobulin E, which sets off a cascade of chemicals to fend off a perceived allergen, such as ragweed. This chemical response triggers the allergic symptoms that people experience. Another antibody in blood, called immunoglobulin G, fights infection.
"What the study showed was that the G antibodies increased proportionate to the strength of the injections given," he said. "So, the weaker injection had less of an effect, and then the medium had more, and the highest dose had the highest effect on the G antibodies."
However, don't expect new-and-improved vaccines to pop up in your doctor's office this ragweed season. Vaccine makers have to clear several hurdles first.
Allergy Therapeutics PLC, the U.K.-bas
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