Nasal spray offers hope in virus fight

A nasal spray originally developed to fight off colds and flu has shown great efficiency at preventing novel coronavirus replication in ferrets, a new study has found.

The treatment reduced virus replication by 96 percent in the animals, according to a study led by Public Health England researchers and published in the preprint research site bioRxiv this week.

The nasal spray contains a compound called INNA-051, which was first developed by Australian biotech company Ena Respiratory to stimulate the immune system and ward off illnesses such as the common cold.

"We have been amazed with just how effective our treatment has been," said Ena Respiratory Managing Director Christophe Demaison. "By boosting the natural immune response of the ferrets with our treatment, we have seen a rapid eradication of the virus."

Ferrets have become important in COVID-19 treatment testing, as the virus replicates in the animals' upper respiratory tracts more so than in most other lab mammals.

Ena Respiratory is hopeful that the spray might prove efficient in preventing the spread of COVID-19 among people, who could shield themselves against the virus with doses taken once or twice a week.

"Individuals exposed to the virus would most likely rapidly eliminate it, with the treatment ensuring that the disease does not progress beyond mild symptoms," Demaison said. "This is particularly relevant to vulnerable members of the community. In addition, the rapidity of this response means that the infected individuals are unlikely to pass it on, meaning a swift halt to community transmission."

Ena Respiratory has raised $11.7 million Australian dollars ($8.33 million) from multiple investors, and the company says human trials for the treatment could begin within four months, following toxicity tests and regulatory approval.

INNA-051 works by initiating several immune responses, including the release of cytokines, which are types of proteins that trigger cellular mechanisms that prevent viral replication.

Roberto Solari, a respiratory specialist at Imperial College London and advisor to Ena Respiratory, said the study, which is yet to be peer-reviewed, represents a "significant development as the world races to find a solution to halt COVID-19 transmission".

"Most exciting is the ability of INNA-051 to significantly reduce virus levels in the nose and throat, giving hope that this therapy could reduce COVID-19 transmission by infected people, especially those who may be pre-symptomatic or asymptomatic and thus unaware they are infectious," Solari said.

A separate COVID-19 nasal treatment, called AeroNabs, is currently being developed by researchers at the University of California San Francisco, or UCSF.

The treatment works by delivering an antiviral aerosol formulation into the nose and throat. The medication could potentially be given daily.

"Far more effective than wearable forms of personal protective equipment, we think of AeroNabs as a molecular form of PPE that could serve as an important stopgap until vaccines provide a more permanent solution to COVID-19," said Peter Walter, a professor of biochemistry at UCSF.