Finnish researchers have developed a novel nasal spray that is effective against all variants of COVID and can prevent infection up to 8 hours.

The nasal spray consists of a molecule, developed by researchers at the University of Helsinki, Finland, that can inactivate the coronavirus spike protein. Cell cultures and animal studies have shown that TriSb92 - the new molecule - protects against coronavirus infection for at least eight hours even in cases of high exposure risk.

In contrast to vaccine protection, the effect of TriSb92 begins immediately after its administration. "In animal models, nasally administered TriSb92 offered protection against infection in an exposure situation where all unprotected mice were infected," said Anna Makela, a postdoctoral researcher at the varsity. The findings have not been peer-reviewed yet.

The TriSb92 molecule is based on an entirely new technical solution developed in Finland for targeting biological drugs. In the study, the solution was utilised to inhibit the functioning of the spike protein on the surface of the SARS-CoV-2 virus. "Targeting this inhibitory effect of the TriSb92 molecule to a site of the coronavirus spike protein common to all variants of the virus makes it possible to effectively inhibit the ability of all known variants, Omicron included, to infect people," Makela said.

In model virus studies, TriSb92 was able to prevent even the spread of SARS - the virus that threatened us in the early 2000s. "In other words, we can fairly confidently assume that future variant of SARS-CoV-2 and perhaps even entirely new coronaviruses that may threaten to cause pandemics are susceptible to it," Makela said.

Nasally administered, the molecule could in the future serve as a kind of biological protection against coronavirus infection that is sprayed on the mucous membranes. "These types of molecules that prevent infections, or antiviral drugs for that matter, cannot substitute for vaccines in protecting the population against the coronavirus disease," said Professor Kalle Saksela from the varsity.

However, there is a great need for novel means with which to enhance the protection provided by vaccines. "TriSb92 could be useful to people whose vaccine protection is insufficient for one reason or another. Depending on the epidemic situation, it could also benefit fully vaccinated individuals when administered before any situation associated with a high risk of exposure," Saksela said.