Peanut allergy vaccine shows promise

Tested in mice, the vaccine suppressed both mild and dangerous allergic reactions like itchiness, wheezing, and shock.

A growing number of people suffer from food allergies, and even in the era of school peanut butter bans and “may contain traces” labeling, avoiding specific foods requires vigilance on the part of allergy sufferers. For some, slip-ups can have dire consequences, resulting in hospitalization or even death. But researchers at the University of Michigan are developing a vaccine that could one day protect peanut allergy sufferers. Their results look promising. Tested in mice, the vaccine redirected how immune cells responded to peanuts, preventing the symptoms of an allergic reaction. The researchers are optimistic the vaccine could be adapted to work with other food allergens as well. We spoke with Jessica O’Konek, the study’s lead author, about the vaccine and its potential.

ResearchGate: Why is it important to develop a treatment for peanut allergies?

Jessica O’Konek: Peanut allergy is one of the most common food allergies, and the incidence is increasing dramatically. Peanuts can cause severe and even life-threatening reactions, sometimes to only very small trace amounts of peanut. There is an urgent need for the development of effective therapeutics.

RG: How did you come to focus on this particular vaccine agent?

O’Konek: Our group has been developing the nanoemulsion vaccine platform for some time, mostly focusing on what you’d think of as more traditional vaccines. The nanoemulsion is an adjuvant, a substance that is added to a vaccine to increase the body's immune response. These tiny droplets form when highly purified soybean oil, detergents, and water are mixed at high speed. The average diameter of the droplets is 350-400 nanometers, roughly 200 times smaller than the average diameter a human hair. Nanoemulsion has previously been shown to promote a strong immune response associated with fighting infection. We theorized that this infection-fighting response would suppress a competing allergic response.

RG: Can you tell us about the mice the vaccine was tested on?

O’Konek: In order to study peanut allergy in mice, we have to make them allergic, which we call sensitizing, to mimic the effects of peanut allergy. Then the mice were given three doses of intranasal vaccine over the course of two months, receiving either the experimental immunotherapy vaccine consisting of peanut protein formulated in nanoemulsion, or a placebo. Two weeks after the final vaccination, the mice were exposed to peanut, and their symptoms and immune functions were assessed.

RG: How did they respond to the vaccine?

O’Konek: Compared to mice that received a placebo, the mice that received the nanoemulsion vaccine were protected against localized symptoms of allergic reaction, such as itchiness and puffy eyes, as well as more severe symptoms, such as wheezing and shock.

RG: How does it work?

O’Konek: The nanoemulsion vaccine actually changes the way the immune system cells respond to exposure to peanut. It redirects the immune responses in a way that both suppresses the allergic response and prevents the activation of cells that would initiate allergic reactions.

RG: How likely is it that this vaccine could one day be available for humans?

O’Konek: The clinical translation of this technology will be facilitated by the fact that the nanoemulsion technology has already been through successful safety studies in humans. We are hopeful that our ongoing preclinical development of the nanoemulsion allergy vaccines will lead to a clinical trial of the vaccine in humans.

One of the things that makes our vaccine unique from other immunotherapies for allergy is that we were able to demonstrate protection after only three doses of the vaccine given at monthly intervals. Importantly, this vaccine works after allergy is established, which provides for potential therapy of allergies in humans.

RG: Does it just work with peanut allergies, or could this method also protect against other types of allergic reactions? 

O’Konek: We are currently testing other common food allergens. We know from our previous work that the nanoemulsion technology can be combined with virtually any protein, so we are optimistic that this could be adapted to all allergies that have the same immunological causes as peanut allergy.

RG: What are the next steps for this research?

O’Konek: We are currently performing further studies in mice to better understand how this vaccine is working to suppress peanut allergy and learn whether protection can be extended for longer periods of time.  We are also extending these studies to different food allergens.


Featured image courtesy of smcgee.