A new vaccine created at the University of Michigan appears to turn off peanut allergies in mice. The nasal vaccine protected the mice from allergic reactions after only three doses.

The mouse models that were allergic to peanuts exhibited symptoms similar to those in humans, which included itchy skin and trouble breathing. Researchers gave the mice a dose of the vaccine once a month for three months and gauged the protection for allergic reactions two weeks after mice were given the final dose of the vaccine.

In the study, immunizing mice with peanut allergies changed how immune cells responded to peanuts.

"We're changing the way the immune cells respond upon exposure to allergens," says lead author Jessica O'Konek. "Importantly, we can do this after allergy is established, which provides for potential therapy of allergies in humans.

"By redirecting the immune responses, our vaccine not only suppresses the response but prevents the activation of cells that would initiate allergic reactions."

Studies are continuing to determine how long the protection lasts, but researchers hope that their method will lead to long-lasting suppression of allergies. They also see their findings as a step toward a future clinical trial to test the method in humans.

"Right now, the only FDA approved way to address food allergy is to avoid the food or suppress allergic reactions after they have already started," O'Konek says. "Our goal is to use immunotherapy to change the immune system's response by developing a therapeutic vaccine for food allergies."

A 2017 study published in the Journal of Allergy and Clinical Immunology found that a daily pill to treat peanut allergies still worked four years after it was given. Earlier, researchers had found that 82 percent of allergic children who were given the probiotic Lactobacillus rhamnosus along with a peanut protein had become tolerant to peanuts compared to only four percent in the placebo group. Those who were tolerant were then asked to eat peanuts as a part of their diet, and after four years, almost 70 percent could eat peanuts without an allergic reaction.

While not a breakthrough in controlling peanut and other allergies, Harvard researchers have developed a more practical, consumer-friendly allergen-detection system that's small enough to put on a keychain.

The $40 portable allergen-detection system called integrated exogenous antigen testing, or Ieat, consists of a handheld device to extract allergens from food and an electronic keychain reader for sensing allergens that wirelessly communicates the results to a smartphone. In less than 10 minutes, the prototype can detect five allergens, one each from wheat, peanuts, hazelnuts, milk, and egg whites, at levels even lower than the gold-standard laboratory assay.