This nasal spray protects against flu and various coronaviruses

Researchers at the University of Houston have developed two promising new nasal sprays to combat respiratory viruses, including the flu and various coronaviruses. These advancements, presented in two consecutive papers published in Nature Communications, could revolutionize the prevention and treatment of respiratory infections.


The team, led by Professor Navin Varadarajan, developed NanoSTING, a nasal spray that activates the immune system to prevent respiratory infections, and NanoSTING-SN, a universal nasal vaccine against coronaviruses. NanoSTING works by using fat droplets to deliver an immune-boosting ingredient, cGAMP, which puts the body's cells on high alert against viral attacks. A single intranasal dose of NanoSTING has been shown to be effective against various strains of SARS-CoV-2 and the influenza virus.

NanoSTING-SN is a nasal vaccine that prevents virus transmission to unvaccinated individuals and combats multiple COVID-19 variants. This multi-antigen intranasal vaccine prevents the virus from replicating in the lungs and nostrils, thus offering protection against many coronaviruses and their variants. According to Navin Varadarajan, this vaccine could break the cycle of transmission and viral evolution, especially in immunocompromised individuals.

Traditional intramuscular vaccines, although effective in preventing illness, are less efficient in stopping infections. NanoSTING-SN, on the other hand, could offer better protection against the transmission of COVID-19 variants and related sarbecoviruses. This innovation holds potential to become a universal vaccine against coronaviruses.

Professor Varadarajan emphasizes that the nasal administration of NanoSTING activates the immune system directly in the nasal cavity, thus preventing viral infections. The results have shown that this spray can protect against both Tamiflu-resistant and Tamiflu-sensitive flu strains, highlighting its broad-spectrum therapeutic potential.

Researchers at the University of Houston hope that these nasal sprays, by activating the immune system rather than directly attacking the virus, will provide effective protection against respiratory infections. Clinical trials could begin within a year, although commercial availability might take longer.

The first author, Ankita Leekha, adds that activating the innate immune system with NanoSTING represents an interesting avenue for protecting humans against multiple respiratory viruses, thus minimizing transmission to vulnerable individuals. The nasal spray approach developed by the team is distinguished by its mechanism of action, which does not directly target the virus but strengthens local immunity in the nose.

These promising developments highlight the importance of continued research to find effective treatments against respiratory viruses.