A new generation of nasal spray antiviral treatments is showing significant promise in preventing and mitigating respiratory illnesses, including influenza and potentially other viruses like COVID-19. Recent research indicates these sprays offer a novel approach to bolstering the body’s natural defenses directly within the nasal passages, where many respiratory viruses first take hold.
Broad-Spectrum Protection: A New Approach to Respiratory Defense
For decades, public health strategies for combating respiratory viruses have largely centered on annual vaccinations and, more recently, the development of specific antiviral medications. However, the emergence of new viral strains and the limitations of vaccine effectiveness have spurred researchers to explore alternative preventative measures. The current wave of research focuses on strengthening the innate immune response within the nasal mucosa – the moist lining of the nose – to create a broader, more adaptable defense system.
One promising development is INNA-051, an investigational nasal spray currently undergoing a Phase 2 clinical trial led by researchers at the University of Maryland School of Medicine. , the university announced the trial, which aims to enroll 1,100 healthy adults aged 18 to 45 who are at increased risk of upper respiratory infections due to exposure to young children or frequent close contact with others. Unlike traditional vaccines that target specific viruses, INNA-051 is described as “virus-agnostic,” meaning it aims to enhance the body’s overall ability to fight off a range of respiratory pathogens, including the flu, common colds, and COVID-19.
“This study represents a new approach to reducing illness from respiratory infections,” said Dr. Justin Ortiz, Professor of Medicine at the University of Maryland School of Medicine and the Principal Investigator for the trial. “Instead of targeting a single virus, INNA-051 strengthens the body’s early immune defenses, which may help mitigate disease caused by multiple respiratory pathogens.”
How the Nasal Sprays Work
The mechanisms of action vary between the different nasal spray formulations under investigation. Some, like INNA-051, appear to work by broadly stimulating the immune system within the nasal passages. Others, such as CR9114 developed by scientists at the Harvard T.H. Chan School of Public Health, utilize antibodies to directly neutralize the virus. CR9114 is an anti-influenza antibody delivered via the nose, and early clinical trials have shown it binds and neutralizes the influenza virus safely and effectively in healthy volunteers.
Researchers found that intranasal CR9114 was safe and well-tolerated in two trials involving 143 participants. The study, published in Science Translational Medicine, noted that the spray may represent an effective preventative measure against influenza. Testing in macaques at various doses and schedules showed that the antibody accumulates in the nose, where the virus initially invades, though the antibodies degrade within approximately three hours. The spray demonstrated optimal protection against both influenza A and B strains when administered twice daily.
Another recently studied nasal spray, detailed in a large human study, significantly reduces seasonal respiratory infections across multiple virus types, including influenza and common coronaviruses. The study design intentionally mirrored real-world conditions, tracking participants throughout an entire respiratory virus season to account for fluctuating exposure risks and changing community transmission patterns. This approach, researchers believe, strengthens confidence in the reported benefits.
The antiviral nasal spray targets the early stages of viral infection within the nasal passages, helping to block viral attachment to nasal epithelial cells. This early intervention strategy aims to reduce viral load and the severity of illness.
Clinical Trial Details and Future Outlook
The University of Maryland’s Phase 2 trial for INNA-051 is a randomized, double-blind, placebo-controlled study. Participants will be randomly assigned to receive either the nasal spray or a placebo to determine if INNA-051 boosts the immune response and prevents illness. The trial is being conducted in collaboration with ENA Respiratory, the manufacturer of the therapy.
The potential benefits of these nasal spray treatments extend beyond individual protection. Widespread adoption could reduce the burden on healthcare systems during peak respiratory seasons and potentially mitigate the risk of future pandemic outbreaks. The ability to offer a preventative measure that works across multiple virus types is particularly appealing, given the constant threat of emerging viral strains.
While the research is promising, it’s important to note that these nasal sprays are still under investigation. Further studies are needed to confirm their long-term efficacy, determine optimal dosing schedules, and assess their effectiveness in diverse populations. The duration of protection offered by these sprays also remains a key area of investigation. For example, the CR9114 antibody spray’s effects lasted approximately three hours, suggesting frequent administration may be necessary for sustained protection.
The development of these nasal spray antiviral treatments represents a significant step forward in the ongoing effort to combat respiratory viruses. By harnessing the power of the body’s natural defenses, these innovative therapies offer a potential new layer of protection against a wide range of seasonal and pandemic threats.
