Non-Allergic Cat: Soon A Pet To Get
Where We Stand: Swiss firm Cytos Biotechnology has developed a vaccine for environmental allergies that doesn’t use the allergen, but instead takes a virus-like particle that’s easily recognized by the immune system and stuffs it with a DNA sequence to stimulate the immune response.
The idea is to minimize side effects and the potential for anaphylaxis associated with current allergy shots.
To date, Cytos has found its shots to be effective for people with allergy symptoms from dust mite and cat allergies. Results are expected this spring from a study of patients with allergic asthma. The company hopes to partner with a leading pharmaceutical manufacturer once the studies are completed.
A U.K. company called Allergy Therapeutics has developed a modified form of immunotherapy to grass, ragweed, and tree pollen that it believes is effective after just four shots over three weeks. The company’s process involves chemically modifying natural allergens to make the vaccine safer to administer at higher doses.
The modified allergens are also supposed to be active for longer in the body, and are given along with an adjuvant that boosts the immune system’s response and encourages allergen tolerance. The company hopes to launch the “grass” versions of the vaccine in some European countries within the next two years.
Another U.K. company, Circassia, is in late-stage development of vaccines for ragweed, dust mites and cat allergy. These vaccines use small bits of the allergen, rather than a whole protein, lessening the risk of reaction to the shot.
Predicting, Preventing Allergy
What’s Involved: Dr. Michael Cyr, assistant clinical professor at McMaster University in Hamilton, believes that proteins and DNA taken from cells in a baby’s umbilical cord at birth could offer a glimpse into an allergic future. Cyr and his colleagues are in the early stages of predicting, then testing, what stem cell markers they should be looking for.
The hope is that in 10 to 15 years they will have found enough markers in genes and on cells that a drop of blood from a newborn or a pregnant woman could produce a prediction as specific as telling parents a child is at five times the average risk for food allergies.
The markers may also help doctors to tailor patient advice, such as whether new parents are safe to keep a cat, or whether they should avoid it because the child is likely to be allergic.
Where We Stand: Cyr’s team recently completed a study of 80 pregnant women and found a strong correlation between the presence of three cell markers in cord blood and how allergic the women were. The three markers are important in the development of cells called eosinophils.
Cyr believes a low level of stem cells with these markers may point to an immaturity in the immune systems of babies at risk for developing asthma and allergy. “We know that something in the first year or two of life switches around, but we think that maybe even at birth, these kids are set up to develop allergies.”
In Europe, meantime, work continues on the allergy prevention concepts of the so-called “Farming Effect.” Dr. Erika von Mutius of Munich and colleagues in several European countries have been studying why the babies of farming women exposed to cows or pigs, fresh dairy products and fodder are far less likely to go on to develop allergies and asthma.
In some of the studies from this mammoth project, evidence of immunity can be clearly seen in the umbilical cord blood. The research has not reached the point of practical application, but von Mutius told Allergic Living in 2008 that perhaps those protective qualities, once isolated, could be harnessed in a vaccine.
More recently, she would not predict when an application might emerge, but hopes it will be before she retires in 13 years. Von Mutius is also the co-author of a 2009 study of expecting mothers that raises this intriguing notion: “One fascinating speculation is that maternal farm exposure might reflect a natural model of immunotherapy … shaping a child’s immune system at an early stage.”
Might we one day see pregnant women sent off to pet cows and do a little farm work? Stay tuned.
First published in Allergic Living magazine, Spring 2010.
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