Princeton Scientists Invest $2M to Develop Allergy‑Blocking Spray for Pets

Meet the married Princeton scientists who spent $2 million developing an anti-allergy solution to keep their pet

Last Updated: March 25, 2026

Would you spend $2,000,000 to get rid of your pet allergies? Married scientists Dr. Evan Zhao and Dr. Siyang Han did just that developing a revolutionary anti-allergy spray called Pacagen. Their inspiration? Their cat, MiaoMiao.

Is There a Cure for Dog Allergies?

While there is currently no universal cure for dog allergies, scientists are developing new ways to neutralize allergens before they trigger symptoms. Pacagen’s spray targets CAN F1 and CAN F2—the primary proteins responsible for dog allergies—preventing it from activating the immune response.

The Cat That Sparked a $2 Million Idea

Zhao and Han’s adored British Shorthair brought an abundance of love—and allergies—into their lives. Han found she was allergic, experiencing a stuffy nose, itchy eyes, and asthma symptoms. The couple couldn’t bear to part with MiaoMiao, so Zhao, with his background in biotechnology, decided to engineer a solution.

“It was so effective that I could stop taking antihistamines altogether.”

MiaoMiao

Have Dog Allergies? This Scientist Couple Engineered a Solution

Zhao turned to a special class of proteins that he studied during his PhD which could be tailored to target specific allergens and turned into a spray.

The resulting products are their cat and dog allergen neutralizing sprays, which are easy to use, effective for anyone with dog or cat allergies, and completely safe for both people and pets.

aerogondo/AdobeStock

The Science Behind Pacagen’s Allergen-Neutralizing Proteins

“The spray contains special proteins we’ve named WhiskerBlock that neutralize specifically the allergen that they were designed for. For the cat spray, the proteins target the allergen Fel D1. For the dog spray, the (different) proteins target the allergens CAN F1 and CAN F2,” explains Zhao. The innovative structure transforms allergenic tetramers into non-reactive monomers.

100,000 People Are Using This Spray to Neutralizes Dog and Cat Allergens Instantly

Simply spray the space you’re in. It works instantly on the allergens. “It was so effective that I could stop taking antihistamines altogether,” says Han.

So far, they have sold 100,000 units. “People are amazing at sending us updates on the product,” says Evan. “Customers are amazed at how well it works.”

This article originally appeared in the award-winning Modern Dog magazine. 
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