Individuals suffering from hay fever may find relief with a novel “molecular shield” designed to stop pollen from penetrating the nasal lining, likely with fewer side effects than traditional treatments.

Hay fever is an allergic response triggered by pollen interacting with IgE antibodies found in the nose, mouth, and eyes, leading to inflammation and symptoms like sneezing and itching. Common treatments, such as antihistamines and steroids, help reduce inflammation but often come with side effects, including drowsiness.

Seeking alternatives, Kaissar Tabynov from Kazakh National University of Agricultural Research and his team first collected blood samples from mice. They then isolated antibodies that did not participate in the allergic response but could bind to major mugwort pollen allergens, the primary trigger for hay fever. This binding action inhibited allergens from connecting with IgE antibodies in laboratory tests. “It acts as a molecular shield,” Tabynov explains.

To evaluate the shield’s effectiveness, the researchers induced mugwort pollen allergies in 10 mice by injecting them with allergens and chemicals to stimulate an immune response.

After a week, they administered small amounts of liquid containing the pollen-blocking antibodies into the noses of half the mice, gradually increasing the dosage over five days. The other group received saline solutions. An hour following each droplet, the mice were exposed to mugwort pollen at concentrations similar to those encountered during peak pollen seasons, according to Tabynov.

Following the final injection, the mice receiving the antibody treatment showed an average of 12 nose rubs over five minutes, in stark contrast to 92 in the saline group.

The researchers aimed to diminish inflammation and confirmed their success by imaging the nasal tissues collected from the mice at the study’s conclusion. This imaging revealed that the treatment not only had localized effects but also systemic ones. “Our research is the first to show that allergen-specific monoclonal antibodies can be administered intranasally to achieve both local and systemic protection against plant pollen allergies,” states Tabynov.

While the researchers did not assess potential side effects, they do not anticipate the adverse reactions associated with oral hay fever treatments, since the antibodies act at the site of allergen entry.

“This study represents a significant breakthrough and underscores the promise of intranasal therapies for allergic rhinitis. [hay fever] It lays the groundwork for early clinical trials exploring this method in humans,” remarks Sayantani Sindher from Stanford University in California.

Nonetheless, translating success in mice to human applications may prove challenging, and the antibodies will need to be modified to ensure they do not provoke an unexpected immune response in humans, Tabynov notes. If all goes well, the team hopes to advance this method to a nasal spray for human use within the next two to three years, he adds.

Such sprays could also address additional pollen types responsible for hay fever. “We envision a future where tailored antibody sprays can be made for individuals with sensitivities to different pollen varieties,” muses Tabynov.