Human Peptide Dermcidin Identified as Natural Antiviral Shield Capable of Inactivating Influenza Before Cellular Infection Begins

Fisabio researchers discover dermcidin peptide in sweat and saliva inactivates the flu virus, explaining why some people are naturally resistant to infection.

By: AXL Media

Published: Mar 31, 2026, 3:49 AM EDT

Source: Information for this report was sourced from Universidad Miguel Hernandez de Elche

The Discovery of an Internal Antiviral Defense

The human body possesses a sophisticated and previously underestimated internal defense mechanism against respiratory infections. A new study led by the Fisabio Foundation has demonstrated that dermcidin, a peptide long recognized for its antibacterial and antifungal properties in sweat, also functions as a potent antiviral agent. Researchers found that this molecule is actively produced by the innate immune system to curb viral replication before it can take hold in the body. According to Dr. María D. Ferrer, the lead researcher of the study, the presence of dermcidin in human secretions provides a natural barrier that interferes directly with the influenza virus's life cycle.

A Novel Mechanism Targeting Viral Fusion

The significance of this discovery lies in dermcidin's unique method of neutralizing the virus, which differs fundamentally from existing pharmaceutical treatments. The peptide works by binding to hemagglutinin, a critical surface protein that the influenza virus uses to latch onto and enter human cells. By attaching to a highly conserved region of this protein, dermcidin induces a structural change that prevents the virus from fusing with the cell membrane. This prevents the infection from ever starting, acting as a preemptive strike. Most current antivirals target a different protein called neuraminidase, which is prone to mutations and the development of drug resistance.

Mapping the First Line of Respiratory Protection

While dermcidin was originally identified as a component of sweat, this research has confirmed its presence at the primary entry points for respiratory pathogens. The team localized the peptide in the nasopharynx, saliva, and tears, suggesting it forms a chemical shield across the most vulnerable mucous membranes. The study revealed that individuals who remained asymptomatic despite exposure to the flu had baseline dermcidin levels up to six times higher than those who became ill. Dr. Paula Corell, the study's first author, noted that these concentrations increase even further during an active infection, reinforcing the peptide's role as a primary responder in the innate immune hierarchy.