A vaccine is being tested in France that could bring hope to millions of allergic asthma patients.
The vaccine, developed at a laboratory in Toulouse by researchers from Inserm and the Institut Pasteur, diminishes the severity of allergic asthma attacks in mice.
This opens the way for clinical testing on humans – potentially good news for the four million people in France (8% of the population) and 300 million people worldwide with the condition.
Professor Gilles Garcia, president of the Asthme et Allergies association, said: “This vaccine only works against allergic asthma, which is around 50% of asthma patients.
“Right now, asthma cannot be cured, only controlled. This research holds hope for a vaccine that could last one, two, or even three years.”
What causes asthma?
Asthma is caused by an overreaction of the immune system, leading to inflammation of the lungs, an overproduction of mucus and hypersensitivity of the bronchial tubes.
It is the cause of around 60,000 hospital admissions a year in France, and 900 deaths.
Asthmatics produce higher levels of two key proteins (IL-4 and IL-13) called cytokines, which at normal levels produce immunity to certain parasites, but which at higher levels provoke asthmatic crises.
Current treatments include Ventolin (given by inhaler), which reduces abnormal contractions of the bronchial tubes, and corticosteroids, which reduce inflammation.
However, these are not sufficient to control severe cases, which need injections of monoclonal antibodies every few weeks. This costs about €15,000 per year per patient.
How does the vaccine work?
“The idea is to develop a treatment that would block production of these two proteins,” says Professor Garcia.
“At the moment, people can get regular injections to control them, but the breakthrough would be a much longer-lasting injection.”
The vaccine works by coupling IL-4 and IL-13 with a carrier protein.
The body recognises this as foreign and produces antibodies against the protein and, by extension, the over-produced cytokines.
“The experience of seeing how fast a Covid vaccine was developed and rolled out makes people hopeful that other vaccines could also be produced with no delay, but this type of research needs to be done within the correct protocols and framework,” says Professor Garcia
“Clinical trials are expected to start later this year, and if all goes well, the vaccine might be generally available in a few years’ time.”
Researchers hope the technology could, in future, be adapted to help people with severe food allergies too.
Pollen season getting longer
The news comes as experts note that the pollen season is starting earlier and lasting longer due to climate change.
Sophie Silcret-Grieu, an allergy specialist who is also a member of Asthme et Allergies, says doctors are seeing more cases of pollen allergies, and in increasing severity, every year. Some patients even end up in hospital.
A severe allergy to pollen, particularly to fine, windborne pollen, can provoke asthma.
Over-the-counter allergy remedies remain first line of defence
In June, French hospitals reported an explosion in the number of asthma cases in accident and emergency departments, attributed to stormy weather that caused pollen to circulate and fragment.
At Argenteuil emergency department in Val-d’Oise, 200 patients were treated for asthma attacks over a single weekend, 10 times more than usual.
The pollen season can stretch into August and even September for some pollen,
Ms Silcret-Grieu says, adding that over-the-counter remedies from pharmacies are still the first line of defence.