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Novel Dust Mite Vaccine on Its Way

If you’re one of the 20 million Americans with an allergy to house dust mites, then you probably know that relief can sometimes be found with allergy shots, also known as immunotherapy. But signing up for years of weekly needles isn’t for everyone. So many of us continue to simply treat the symptoms – the congestion, the sneezing, the itchy eyes and even asthma flare-ups.

But a new study could change that. Researchers at Monash University in Australia are working on a dust-mite vaccine that, if successful, would have the potential to cure sufferers in just two to three doses. Professor Els Meeusen is applying her experience in infectious disease vaccines to the world of allergy. She believes the addition of a new ingredient into the vaccine could be the magic bullet allergy sufferers have been waiting for.

Allergic Living’s Kim Shiffman spoke with Els Meeusen to find out what that ingredient is, and when the vaccine might be available.

Why focus on immunotherapy as a treatment for dust mite allergy?

It’s the only treatment that could be a cure. All the others are just to keep allergic symptoms under control, but they don’t cure anything.

How would your vaccine be different than the one that’s been available for years?

The current house dust mite allergy vaccine is given at continuously increasing doses over a period of years. You have to be very careful giving it – it can be a little bit dangerous to use because it’s not well known how it works, and if you don’t use it properly, it could cause a serious reaction. It’s also not quite clear if or when it’s going to start working, and there are no clear markers to actually assess if it’s working.

What our work will do is try to speed up the vaccine effect, a bit like in the work I do with infectious diseases, where you only have to give two or three injections before you get good immunity. If we can achieve the same immune deviation – changing the immune system by vaccination using the same principles as infectious diseases – then we may be able to have a more effective and quicker vaccination regime for house dust mite allergy.

Next Page: More questions on the vaccine

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What would be different about your vaccine that would allow it to work in just two or three doses?

At the moment, allergy vaccines contain just the allergen itself. We want to find an adjuvant to add that will boost the immune process and hopefully accelerate the vaccine effect. [An adjuvant is an agent added to a vaccine to increase or aid its effect.]

In infectious diseases, scientists have discovered that there are certain molecules associated with infectious bacteria that are particularly good at switching on the immune response and getting it going. So, apart from the actual antigens, which are necessary to recognize the organism and attack it, there are also molecules called innate stimulators, and they are used in adjuvants. For a long time, nobody really knew how they worked, but now we are starting to recognize how they work in molecular detail. We want to use these same innate stimulators that really get the immune system going – and potentially they have different stimulators for different types of immune responses, so we have some that we can recognize that alter the immune system into not reacting with an allergic response.

How will you test what to add to the vaccine?

We’re using sheep. In the first step of our research, we showed that we can induce in sheep the same kind of allergic response to house dust mite that some humans have. We’ve given them the allergen in their lungs and have shown that they have the same asthmatic-type response as humans. The next step is to vaccinate them to see what the effect is and compare it to normal, standard allergy vaccine treatment. Our sheep model is much more relevant to the human condition than mice.

I can’t help but wonder: what does a sheep having an allergic reaction look like?

Sheep are quite similar to humans, especially in the lungs. They actually develop the same lung constrictions and airway hyper-reactivity as humans and we can measure it in a very detailed way. We can also measure the allergen-specific IgE response.

What are your next steps?

We’ve established the model with sheep, and now we’re waiting for the next grant, with which we’ll use the model to do the vaccine study in the next two years …. Getting to human trials in the allergy area seems to be quicker than in infectious diseases. People could be trying the vaccine maybe even in the next five years.