Researchers stimulate immune system to protect against virus-related disease

The United Kingdom government is funding the development of a nasal spray that could act as a preventative treatment against novel coronavirus infection.

The spray, which is called SPORCOV, will deliver killed bacterial spores to the nose and throat, stimulating an immune response that in turn could provide protection against COVID-19.

Other companies and institutions are exploring COVID-19 sprays, including Australia-based Ena Respiratory, which makes the INNA-X nasal treatment, and engineers at the University of California San Francisco, who have created the AeroNabs medication.

Developers claim that nasal sprays have the potential to provide the first line of defense against the novel coronavirus. AeroNabs inventor Peter Walter describes such sprays as a "molecular form of personal protective equipment", that could serve as an important stopgap until vaccines provide a more permanent solution to COVID-19.

SPOR-COV is being co-developed by two UK-based biotech companies, SporeGen and Destiny Pharma. The British government's innovation agency Innovate UK has awarded the project an initial 800,000 pounds ($1.04 million) in funding.

Pre-clinical safety and efficacy studies for the project are being led by Aras Kadioglu, a professor of bacterial pathogenesis at the University of Liverpool, and Xu Rong, an immunologist working at Liverpool through the China Scholarship Council.

SPOR-COV was initially developed to provide protection against the influenza virus, and showed high efficacy at stopping infection in animal trials. When the pandemic broke out, SporeGen shifted its focus to the novel coronavirus.

"SPOR-COV potentially has value as a universal system for combating other viral diseases such as COVID-19," said Simon Cutting, chief executive of SporeGen. "If successful, we foresee a novel approach against COVID-19 and for future, similar pandemics. The SPOR-COV approach, unlike traditional vaccination, focuses on innate immunity and may not be impaired by new mutational variants."

Previous research has shown that heat-killed bacteria spores can kickstart an innate immune response in humans by interacting with special immune proteins called toll-like receptors and by boosting activity in dendritic cells, which act as a bridge between the external environment and the lymphatic system.

The team at Liverpool will first aim to determine if the SPOR-COV treatment is effective at warding off novel coronavirus in mice. "Our aim is to determine the prophylactic efficacy of treatment against pandemic viral infections such as influenza and COVID-19, using specially developed animal models of infection, and to better understand the immune processes involved," Kadioglu said.

In late September, the INNA-X treatment proved to be highly effective in preventing novel coronavirus infection in ferrets. The treatment reduced virus replication by 96 percent in the animals, according to a study led by Public Health England researchers, and published on the preprint research site bioRxiv.

Instead of using spores, the INNAX treatment uses a molecule called INNA-051 which initiates several immune responses, including the release of cytokines, which are types of proteins that trigger cellular mechanisms that prevent viral replication.