Mila Ortigoza, MD, PhD

The flu virus has a remarkable ability to spread among people, but we still do not fully understand what makes an infected person contagious. To explore this, we developed a model using baby mice to study how both the virus and the host’s response to infection affect contagiousness. We discovered that flu infection in mice triggers a strong immune reaction called inflammation, which is the body's first line of defense against infection. Interestingly, highly contagious flu viruses provoke a stronger inflammatory response than less contagious ones. This response increases genetic and protein activity in the nose, leading to more phlegm production, which is a key cause of a “runny nose.” While inflammation is typically a sign of the body fighting an infection, our findings suggest that certain immune responses can unintentionally boost virus spread. This study highlights the virus’s clever ability to use the host’s defense system to maximize its transmission.

Funded in Memory of Richard Starr