Six weekly shots supress hay fever for years - study
October 04, 2006 10:11:14 (ET)
By Gene Emery
BOSTON, Oct 4 (Reuters) - A new allergy treatment may offer long-term relief from the miseries of hay fever with only six weekly shots, instead of injections once or twice a week over three to five years, researchers reported on Wednesday.
Not only does the relief seem to last more than a year, the technique may be applied to other substances that spark allergic reactions, said Peter Creticos of the Johns Hopkins Asthma and Allergy Center in Baltimore, leader of the team.
"We're interested in grass, we're interested in dust mites, we're interested in cats," he told Reuters.
Of the 40 million hay fever sufferers in the United States, about 20 million to 30 million are allergic to ragweed, a yellow flowering weed which appears east of the Rocky Mountains and is a top cause of hay fever symptoms in the autumn season.
"Ragweed is misery for people in the fall," said Creticos.
Recipients of the treatment, known as AIC, had fewer hay- fever symptoms, used less allergy medication and reported a better quality of life than volunteers who received six dummy shots.
"We're not just treating the symptoms, we're targeting the fundamental defects in the immune system that cause allergy," said Creticos. "It's really exciting."
Even if larger tests confirm the findings, published in the New England Journal of Medicine, the shots probably wouldn't be available to the public until 2009 or 2010 at the earliest.
The treatment is being developed by Dynavax Technologies Corp. of Berkeley, Calif. Four of the 11 authors of the Journal study have financial ties to Dynavax or a financial interest in the process.
AIC stands for Amb a 1-immunostimulatory oligodeoxyribonucleotide conjugate.
ALLERGIC REACTIONS
The current system of shots used by doctors for nearly a century is effective but carries the risk of a life-threatening allergic reaction. They are also so inconvenient many people forego the treatment.
The Creticos study involved 25 volunteers who experienced ragweed allergic problems each fall season.
The treatment mixes a component of ragweed that sets off the allergic reaction with a synthetic chunk of DNA that stimulates the immune system.
Six weeks of shots, given prior to the 2001 ragweed season, produced more than a year of relief for 14 volunteers, gains not seen in the 11 who received placebo injections. Not only did the AIC recipients do better that fall, they also scored better on measures of symptoms in the peak of the 2002 season.
For example, while placebo recipients typically took antihistamines for eight days and decongestants for four days, the AIC patients felt they needed few, if any, allergy medicines.
The researchers did not track the volunteers after the 2002 season because the number of people willing to continue in the study was too small to be meaningful, Creticos said. A larger study that will try to enroll 140 volunteers is underway.
There were no short-term side effects from the treatment, but the longer-term risks need to be assessed, the researchers said.
People develop an allergic reaction because their immune system overreacts to a substance.
"Allergy shots haven't changed since 1911 when they first started," Creticos said. "Now we're beginning to learn how to redirect the inappropriate immune response and shut it down much more quickly and much more efficiently for, we hope, at least two ragweed seasons, if not longer."
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