Weekly Nasal Spray Could Block Colds, Flu, and COVID

Imagine stopping a cold before it ever starts with just one weekly spritz up your nose.

That's the promise of INNA-051, a breakthrough nasal spray developed by Melbourne-based ENA Respiratory. Unlike vaccines that teach your body to fight specific viruses, this spray activates your nose's natural defenses to block multiple respiratory viruses right where they enter.

The US Department of Defense has invested nearly $10 million in the technology because it could be a game changer for military personnel who can't afford to get sick during operations. But the spray isn't just for soldiers. It's designed for everyone who's tired of losing days to respiratory infections.

The spray works by priming the antiviral defenses already living in your nasal passages. When cold, flu, RSV, or coronavirus particles try to invade, your body responds faster and stronger, reducing the viral load before you feel symptoms. For healthy adults, that means less time feeling miserable. For people with asthma or compromised immune systems, it could be life saving.

ENA Respiratory raised $22.4 million last year to push the spray through trials. The company announced this month it's launching its first clinical trial with patients who have asthma, set to begin in early 2027. The spray is already working through a Phase IIa community study in the United States.

The research behind INNA-051 came from the University of Melbourne's Department of Microbiology and Immunology. Scientists there discovered how to trigger TLR2/6 receptors, proteins that act as the body's early warning system for viral invaders.

The team is now focused on perfecting a dry powder version of the spray. Powder lasts longer on the shelf than liquid, making it easier to store and transport. That convenience matters whether you're stationed overseas or just keeping a bottle in your medicine cabinet.

The Ripple Effect

The backing from both the US military and the COPD Foundation shows how widely this could help. Military units could stay healthier during deployments. People with chronic respiratory conditions could avoid dangerous complications. Parents could protect kids before cold and flu season hits hard.

The beauty of INNA-051 is its simplicity. Instead of getting multiple vaccines or taking daily medications, one weekly spray could shield you from the respiratory viruses that cause most sick days. It doesn't stop every infection completely, but it significantly reduces how sick you get and for how long.

If the upcoming trials succeed, we could see a future where seasonal respiratory infections become minor inconveniences instead of weeks lost to illness.