Imagine having a peanut allergy so severe that you must carry an EpiPen with you at all times to avoid life-threatening anaphylactic shock from accidental exposure to as little as one-quarter of a nut. Now imagine that a series of three vaccines could cure you of that allergy – for life.
According to a study published in the Journal of Allergy and Clinical Immunology, researchers from the University of Michigan are inching closer to this feat after achieving promising results with their intranasal vaccine that prevents dangerous inflammatory responses by harnessing the immune system’s own self-regulating processes.
As the experiment was conducted in mice, it’s too soon to bust out Reese’s Cups in celebration, but the team is optimistic that their method could someday cure people of numerous types of food allergies, and beyond.
"We're changing the way the immune cells respond upon exposure to allergens," lead author Jessica O'Konek said in a statement. "Importantly, we can do this after allergy is established, which provides for potential therapy of allergies in humans."
Symptoms of an allergic reaction to food – including itchiness, rash, and airway constriction – are induced by the actions of a type of antibody called IgE. Current therapies to prevent IgE-mediated allergic reactions work by continually exposing the immune system to the allergen until desensitization causes the response to lessen over time. Unfortunately, these methods never rid a patient of their allergy entirely, and their overblown allergic response returns once exposure stops.
Scientists have speculated that targeting the IgE-mediated response alone has been unsuccessful because another of the body’s immune response pathways, called TH2, remains unaffected. People with allergies appear to have an overactive TH2 system, wherein white blood cells secrete pro-inflammatory molecules that activate the IgE pathway, and suppressed versions of the counteracting TH1 and TH17 pathways.
In 2014, a different team also headed by James R. Baker, Jr, proved that an immune system-boosting agent, referred to as NE, could boost TH1 and TH17 responses to an antigen in mice – and thus potentially modify harmful TH2 responses – when a combination of the antigen and NE were introduced to the body through the membranes of the nose.
So, for the current study, Baker’s team created an intranasal vaccine composed of NE and peanut flour and administered it to allergic mice once a month for three months.
Two weeks after the last immunization, mice showed remarkably lower outward signs of allergic response during a peanut food challenge, and laboratory tests confirmed that TH2 responses and IgE production were drastically lower.
The protective effect remained for another two weeks. Per the UM press release, research into the vaccine’s efficacy in the long term is ongoing.