It is estimated that about 1 in 10 people, and 50% of asthmatic children, suffer from more or less acute forms of cat allergy. Among sneezing, difficulty breathing, itching and irritation, many of the allergic people prefer – or are actually forced to protect their health – to live far away from these felines. And, framing the problem from the other point of view, many domestic cats are moved away from the houses when one or more of the tenants starts to manifest an allergy, ending up abandoned on the street or in a cattery.

However, the problem may be close to a solution, at least partial. According to the results of a scientific study published a few days ago in the prestigious Journal of Allergy and Clinical Immunology, a vaccine is already in an advanced development phase that could eliminate (or at least significantly reduce) the problem of allergy to cats by intervening directly on the protein that acts as an allergen.

How the vaccine works

The first information to know is that it is not humans who are vaccinated, but cats. If this avoids the risk of possible perplexity in the public opinion for an additional vaccine to be given to children and adults, at the same time, however, it makes it clear that nobody will be completely cured of the allergy: the idea, in fact, is to immunise the domestic cats in homes where at least one person with cat allergy lives, so that the felines – thus rendered hypoallergenic – can continue to stay at home without causing inconvenience. For all other unvaccinated cats, on the other hand, the problem of allergies would remain exactly as it is now.

From a technical point of view, the vaccine acts on the Fel d 1 protein, which in cats is mainly present in saliva and sebaceous glands, representing (through the hair where it accumulates) the main trigger for allergy.

The vaccine developed by a research team of the University Hospital of Zurich, Switzerland, is designed to induce a controlled autoimmune reaction in cats , so that the Fel d 1 protein is attacked and neutralised by the immune system, without obviously causing harm to the health of the cats themselves. The vaccine, which in honour of the concept of hypoallergenic cats was called HypoCat, was made from the tobacco mosaic virus, obviously inactivated and used in combination with an adjutant.

Image: Elena Leonova / Getty Images

How far we are with experimentation

At the moment, as the scientists have written, 54 cats have already been subjected to the experimental treatment , which did not show any adverse effect on vaccination, after a series of in vitro tests had already been completed over the last 10 years by encouraging results. In all cases the desired immune response was recorded, although the elimination of the allergen was sometimes total and sometimes only partial.

What is still to be verified – and this is not a detail at all – is how the reduction of the Fel d 1 protein results in an effective decrease in allergic symptoms in people. Even if some positive effect seems to be more than plausible, there is currently no experimental confirmation of the benefit in quantitative terms.

According to what is possible to predict at the moment, the estimated time for the arrival of the vaccine on the market is about three years. Regardless of its level of effectiveness, the improvement compared to the current situation should be significant. For now, in fact, there is no specific remedy against allergy to cats, if not the use of classic antihistamine treatments and the obvious advice to reduce direct contact with cats and their hair. At best, then, the new vaccine will be able to reduce the incidence – especially in children – of chronic diseases such as asthma, which as is known can be induced precisely by prolonged exposure to allergens.