The Cat Flea Vaccination: What You Should Know

JoAnna Pendergrass, DVM
By JoAnna Pendergrass, DVM on Apr. 6, 2018

With the start of spring, we can finally breathe a sigh of relief that the tight grip of winter has finally given way to warmer temperatures. However, with warmer temperatures comes the nuisance of fleas for our beloved cats.

Cat fleas (Ctenocephalides felis) are tiny external parasites that cause big problems. Because they feed on a cat's blood, fleas can cause intense itching that leads to incessant scratching and skin wounds that can become infected. Fleas can also cause anemia and spread diseases like tapeworm. In addition, while adult female fleas feed, they lay numerous eggs that fall off the cat and develop into mature adult fleas. These new fleas are hungry and ready to jump onto an unwitting (and unwilling) cat, continuing the cycle.

Current cat flea treatments rid both the cat and environment of fleas. To treat an affected cat, a veterinarian will prescribe long-acting topical medications that contain insecticides, which kills the fleas, or insect growth regulators (IGR), which disrupts the flea's life cycle. Treating the environment entails frequent and thorough cleaning, spraying IGR-containing products inside the home, and possibly even hiring a pest control company. Plus, flea control products aren't exactly environmentally friendly.

A Vaccination for Cat Fleas

Though not commercially available yet, cat flea vaccines present an environmentally-friendly solution for cat flea infestations. Rather than killing the fleas, a cat flea vaccine would reduce cat flea populations by making it harder for the fleas to carry out normal biological functions-like reproduction-after feeding on a vaccinated cat. Sounds like a good idea, right? Unfortunately, up until now, cat flea vaccine development has hit a roadblock: finding antigens (foreign substances) to put in the vaccine. These antigens would stimulate a cat's immune system to produce proteins called antibodies that would fight back against the fleas.

To get around this roadblock, researchers have explored other methods, one of which is called reverse vaccinology. Reverse vaccinology involves scanning an organism's genome (genetic material) using advanced laboratory techniques, then selecting genes that code for vaccine-worthy antigens. A research team recently used reverse vaccinology to analyze the cat flea genome, identify antigens, and develop several cat flea vaccines using those antigens.

Next, the researchers vaccinated healthy cats and then infested them with adult, unfed fleas. After the infestation, the researchers studied the vaccines' effects on several biological functions of cat fleas, like fertility, mortality and egg hatchability. The vaccinated cats' immune systems recognized the antigens and responded by making protective antibodies. The fleas, after feeding on the vaccinated cats, were less fertile and their eggs didn't hatch very well.

The overall vaccine effectiveness-the ability to control cat flea populations-ranged from 32 to 46 percent. The researchers concluded that the cat flea vaccines controlled cat flea populations by negatively affecting flea reproduction. Even with these promising results, cat flea vaccines will need to undergo much more testing before they become commercially available. In the meantime, talk to your veterinarian about cat flea vaccines and ask if the vaccine may be a good choice for your cat.

JoAnna Pendergrass, DVM


JoAnna Pendergrass, DVM


Dr. JoAnna Pendergrass is a veterinarian and freelance medical writer. She is the owner of JPen Communications, a medical communications...

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