A cat vaccine is being developed to decrease the amount of allergy that cats produce. Cats are found in about 25% of households in the United States and allergy to cats is found in approximately 10% of the population. The major cat allergen found in saliva and dander is called Fel d 1, and this drives allergy hypersensitivity causing typical allergy symptoms of sneezing, nasal congestion, runny nose, itchy eyes and in more severe cases, coughing, wheezing and shortness of breath.
Treatment of cat allergy typically consists of antihistamines and steroids, which have limited efficacy and side effects. Another approach is allergy shots or allergy immunotherapy, where repeated injections are given to the person for a minimum of 2 to 3 years with increasing dosages of Fel d 1, to desensitize the cat allergic person. In recent decades, cat allergens have been standardized and its efficacy has greatly improved.
Other approaches have tried to reduce the cat allergen load in the household by washing cats, keeping them out of the bedroom and use of HEPA filters. However, these efforts are not implemented long term as often these treatments don’t work. As a consequence, cat owners frequently have to give their cats away or just suffer in the home.
Fel d 1 is produced by salivary, skin, lacrimal and perianal glands. Male cats exhibit higher levels of the protein. A vaccine targeting Fel d 1 in cats will affect the allergic response by inducing antibodies against it. These antibodies will bind to Fel d 1 and thus decrease or neutralize its allergenic effect in humans. The first steps in the development of this new cat vaccine had some promising results, the authors reported the following:
- 54 cats were immunized with the cat vaccine, a version of Fel d 1, the protein secreted by cats that drives allergy in most patients with cat allergy.
- The vaccine induced neutralizing antibodies that bound to Fel d 1 and decreased the allergenicity of cat tears, a major source of Fel d 1.
- Studies have shown that the vaccine is well tolerated and does not induce severe side effects in cats.
Thus it might be possible to reduce or even prevent allergic reactions against in cats in cat allergic people. Once this is established, the cat vaccine will be tested in field and safety studies. Positive data could result in the vaccine reaching the market in 2022.
This possible alternative therapy of cat allergy in human subjects, by vaccinating the cat against Fel d 1, thereby reducing its level in cat secretions, will potentially reduce allergic reactions in people.
Dr. Yudy K. Persaud, Chief of the Allergy division at BronxCare Health System, commented “For over a century we have been giving allergy vaccines successfully to patients. Now we are at the point where science has allowed us to give the vaccines to the animals instead to prevent symptoms in their owners. This has opened up potentially many new allergy strategies.”
This vaccine is being called “HypoCat”, the CEO of HypoPet who is developing the vaccine said he’s hoping to bring the “much-needed product” to the US and Europe. HypoCat if successful, may lead to HypoDog whose major protein is Can f 1.