Most viruses enter our bodies through the nose. When we catch an airborne infection like the flu or COVID, we breathe out tiny droplets that carry the virus. Healthy people nearby can inhale these droplets, allowing the virus to attach to the cells in their nasal passages and infect them. The virus then replicates and can be released back into the air when a sick person sneezes, coughs, laughs, sings or breathes.
Vaccines can help fight these viruses but aren’t foolproof, as vaccinated people can still get infected and spread the virus. Masks are also beneficial but can leak, and many people wear them incorrectly or not at all.
In a new study, investigators from Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, have created a drug-free nasal spray that may offer broad-spectrum protection from respiratory infections by COVID-19, influenza, everyday cold viruses, and pneumonia-causing bacteria. The spray is long-lasting, safe, and, if validated in humans, could be vital in reducing respiratory diseases and safeguarding public health against new threats.
Credit: Courtesy of Randal McKenzie, McKenzie Illustrations.
Scientists called this spray a ‘Pathogen Capture and Neutralizing Spray (PCANS)’.’ They created this spray using ingredients from the FDA’s Inactive Ingredient Database (IID), previously used in approved nasal sprays, or from the Generally Recognized as Safe (GRAS) list of the FDA.
Using these compounds, scientists created a drug-free formulation to block germs in three ways. PCANS forms a gel-like matrix that traps respiratory droplets, immobilizes the germs, and effectively neutralizes them, preventing infection.
Scientists tested PCANS in a 3D-printed replica of a human nose. They found that when sprayed in a nasal cavity model, PCANS captured twice as many droplets as mucus alone.
Primary author John Joseph, PhD, a former postdoctoral fellow at Brigham and Women’s Hospital, said, “PCANS forms a gel, increasing its mechanical strength by a hundred times, forming a solid barrier. It blocked and neutralized almost 100% of all viruses and bacteria we tested, including Influenza, SARS-CoV-2, RSV, adenovirus, K Pneumonia and more.”
Experiments in mice showed that a single dose of the PCANS nasal spray could effectively block infection from the influenza virus (PR8) at 25 times the lethal dose. Virus levels in the lungs were reduced by over 99.99%, and the inflammatory cells and cytokines in the lungs of treated mice were normal.
Co-senior author Yohannes Tesfaigzi, PhD, AstraZeneca Professor of Medicine in the Field of Respiratory and Inflammatory Diseases at Brigham and Women’s Hospital, said, “The formulation’s ability to inactivate a broad spectrum of pathogens, including the deadly PR8 influenza virus, demonstrates its high effectiveness. In a rigorous mouse model study, prophylactic treatment with PCANS demonstrated exceptional efficacy, with treated mice exhibiting complete protection, while the untreated group showed no such benefit.”
Journal Reference:
- Joseph, J et al. “Toward a Radically Simple Multi-Modal Nasal Spray for Preventing Respiratory Infections” Advanced Materials. DOI: 10.1002/adma.202406348