New research has found early promise in a vaccination against chronic allergic asthma. It’s only been carried out in mice so far, so it’s still very early days, but it could potentially pave the way for a long-term approach to treat severe asthma. Off the back of these promising results, the researchers told IFLScience that they’re already in discussions with several hospitals in the hopes of carrying out human trials in the next couple of years.
To wind back a little, asthma causes wheezing, shortness of breath, and a tight feeling around the chest for around 262 million people worldwide. It’s caused by the inflammation in the lungs’ airways, causing them to narrow. While asthma can have a number of different triggers, the root cause of this inflammation is often an overreaction from the immune system against an allergen. Addressing this inflammation is key to treating the condition, but it can prove difficult in some people with severe asthma.
“Most asthma patients are treated with inhaled corticosteroids, but patients with severe asthma typically do not respond well to corticosteroids. These patients are [currently] treated with recombinant antibodies, which are costly and require frequent reinjections. We therefore aimed at designing a vaccine strategy for asthma which would induce long-term protection without the need of frequent reinjections of the drug,” Laurent Reber, PhD, study author from the French National Institute of Health and Medical Research (INSERM), told IFLScience.
The new project is a collaboration between INSERM (Laurent Reber Lab, Infinity, Toulouse), the lab of Pierre Bruhns (Pasteur Institute, Paris), and the French Biotech company NEOVACS. Published in the journal Nature Communications today, the results demonstrate how their vaccine protects against allergy-induced asthma for at least 11 weeks in mice.
The vaccine works a bit like a typical vaccine against a germ, but instead it targets cytokines, signaling proteins pumped out by the immune system. More specifically, the vaccine targets two cytokines signaling molecules — interleukin-4 (IL-4) and interleukin-13 (IL-13) — which asthma sufferers are known to have elevated levels of.
Within the vaccine, recombinant IL-4 and IL-13 are paired up with the "carrier protein" CRM197, a mutated non-toxic version of diphtheria toxin that's currently used in some FDA-approved vaccines. This was injected into the muscles of mice that had been genetically tweaked to contain human cells, inducing their immune system to create antibodies against IL4 and IL13.
In turn, this was found to help reduce asthma symptoms, such as airway hyperreactivity, inflammation, and mucus production. The results suggested that the vaccination suppressed levels of these two cytokines for at least 11 weeks while reducing features of chronic asthma, such as mucus production, for up to 15 weeks.
So far, so good, though it's not guaranteed these results will translate well in humans. To find out, the researchers hope to start a clinical trial within the next couple of years.
“We have patented this vaccine, and we continue to collaborate with NEOVACS with the aim to initiate a multicentric trial for within two years (now in discussion with several hospitals in France). Importantly, since IL-4 and IL-13 are implicated in many types of allergies, including food allergy and atopic dermatitis, we also envision that the vaccine will have long-term beneficial effects in many other allergic diseases,” said Dr Reber.