Swine flu can worm its way deeper into the body than seasonal flu, a dangerous capability that could result in increased fatalities if the virus mutates, AFP reports. Seasonal influenza is able to bind only to the tissues in the nose, throat, and upper airway—that’s why it causes runny noses and scratchy throats. But in a new study, the (A)H1N1 subtype of the flu was able to implant itself in tissues in the lungs.
The bonds swine flu forms with receptors in lung cells are weaker than those in tissues battered by traditional flu—but natural selection could change that, the study's authors warn. "If the flu virus mutates in the future, it may attach to the receptors deep inside the lungs more strongly, and this could mean that more people would experience severe symptoms," said the lead researcher.