Virus World

Nasal sprays for pre-exposure prophylaxis against respiratory infections show limited protection (20–70%), largely due to their single mechanism of action—either neutralizing pathogens or blocking their entry at the nasal lining, and a failure to maximize the capture of respiratory droplets, allowing them to potentially rebound and reach deeper airways. This report introduces the Pathogen Capture and Neutralizing Spray (PCANS), which utilizes a multi-modal approach to enhance efficacy. PCANS coats the nasal cavity, capturing large respiratory droplets from the air, and serving as a physical barrier against a broad spectrum of viruses and bacteria, while rapidly neutralizing them with over 99.99% effectiveness.

The formulation consists of excipients identified from the FDA's Inactive Ingredient Database and Generally Recognized as Safe list to maximize efficacy for each step in the multi-modal approach. PCANS demonstrates nasal retention for up to 8 hours in mice. In a severe Influenza A mouse model, a single pre-exposure dose of PCANS leads to a >99.99% reduction in lung viral titer and ensures 100% survival, compared to 0% in the control group. PCANS suppresses pathological manifestations and offers protection for at least 4 hours. This data suggest PCANS as a promising daily-use prophylactic against respiratory infections.

Published in Advanced Materials  (Sept. 24, 2024):

https://doi.org/10.1002/adma.202406348 

Researchers have developed a molecule that, when administered nasally, effectively prevents the disease caused by all known variants COVID. University of Helsinki researchers have developed a molecule that, when administered nasally, effectively prevents the disease caused by all known variants of the SARS-CoV-2 virus. The molecule, called TriSb92, can be a crucial tool in preventing the transmission and spread of the virus, particularly in anticipation of future pandemics. In laboratory animal studies, TriSb92 was confirmed to offer effective protection against coronavirus infection by identifying a region in the spike protein of the coronavirus that is common to all current variants of the virus and inhibiting its functioning. The molecule is effective in preventing infection when administered nasally, even after a few hours of exposure, unlike face masks. Postdoctoral Researcher Anna R. Mäkelä from Professor Kalle Saksela’s research group explains that experiments carried out in cell cultures indicate that TriSb92 also encompasses the very latest variants, including XBB, BF7, and BQ.1.1.  Moreover, the molecule remains fully functional at room temperature for at least 18 months, making it well-suited for use as a nasal spray. The results have been published in the Nature Communications journal.

While the worst stage of the coronavirus pandemic is, at least for the time being, behind us, nasally administered protection can be a crucial help in preventing the spread of the virus in the future.  The latest variants of the virus effectively avoid the immune protection provided by both vaccines and the COVID-19 disease, and current vaccines are not effective in preventing transmission, Mäkelä says. The nasal spray can also protect individuals who do not gain sufficient immunity from vaccines, such as immunocompromised individuals and the elderly. According to the researchers, the molecule could also work against future animal-borne close relatives of SARS-CoV-2, which are expected to be the cause of entirely new coronavirus pandemics.  The region in the coronavirus’s spike protein affected by the TriSb92 molecule has remained almost unchanged in all viral variants so far emerged, making it effective against future SARS-CoV-2 variants, Mäkelä confirms. The molecule is easily and inexpensively produced and could be a very important first line of defence in curbing such a new pandemic, pending the development, production, and distribution of vaccines, she adds. The sherpabody-technology used by the researchers is also applicable to the prevention of many other viral diseases, particularly influenza and other respiratory viruses.  “The whole approach stems from a technical solution based on a binder protein platform developed in Finland, which was not originally intended for the development of an antiviral drug. It provides an opportunity for many other new initiatives based on the accurate identification of diseased cells or pathogens in patients,” Mäkelä says. In the next stage, the molecule must be tested in clinical trials, after which it could be made commercially available. “Successful commercialisation of the nasal spray could lead to the creation of a thriving Finnish business,” Mäkelä points out.

Research cited published (March 24, 2023) in Nature Communications:

https://doi.org/10.1038/s41467-023-37290-6