Drug-free nasal spray prevents infection by trapping viruses in the nose

Once squirted into the nose, the spray forms a gel (blue) that traps and neutralizes microbes. Randal McKenzie, McKenzie Illustrations –

By Ben Coxworth
2024 Sep 25
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Nobody wants to get a respiratory infection such as COVID-19 or the flu, but vaccines aren’t 100% effective, and constantly taking preventative drugs can be problematic. That’s where a special nasal spray may come in, as it’s been shown to prevent such illnesses (in mice) without the use of drugs.

Respiratory viruses typically enter our body within droplets that are exhaled by infected people, and inhaled through our nose. Those viruses proceed to reproduce while infecting the cells lining our nasal passageways. When we subsequently sneeze or even just exhale, their progeny are ejected within fluid droplets to infect more people.

In an effort to trap and neutralize viruses within the nose, scientists from Harvard-affiliated Brigham and Women’s Hospital looked to the US Food and Drug Administration. More specifically, they sought out ingredients that had previously been used in FDA-approved nasal sprays, or that were on the FDA’s Generally Recognized as Safe list.

The resulting substance is known as the Pathogen Capture and Neutralizing Spray (PCANS), and it contains no drugs of any kind.

Instead, the spray forms a gel that lines the inside of the nose. While this gel doesn’t affect the user’s breathing, it does trap any viruses or bacteria that are subsequently inhaled into the nose, immobilizing them until they die.

In lab tests, the spray protected mice from a mouse-adapted form of the H1N1 influenza virus, even when that virus was administered at 25 times the lethal dose. What’s more, virus levels in the animals’ lungs were reduced by over 99.99% as compared to an untreated control group of mice. The spray was retained in the rodents’ noses for up to eight hours, and was effective at blocking infection for at least four hours.

Although PCANS has yet to be tested on humans, it has been used in a 3D-printed model of a human nose, where it captured twice as many microbe-containing droplets as mucus alone.

“It blocked and neutralized almost 100% of all viruses and bacteria we tested, including influenza, SARS-CoV-2, RSV, adenovirus, K Pneumonia and more,” says Dr. John Joseph, primary author of the study.

The research is described in a paper that was recently published in the journal Advanced Materials. And if you suffer from allergies, take note – the scientists believe the spray could one day also be used on a daily basis to trap and neutralize allergens.

Source: Brigham and Women’s Hospital
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