Fighting viruses is as easy as breathing

The average person will take more than 600 million breaths over the course of their life. Every breath stretches the lungs' tissues with each inhale and relaxes them with each exhale. The mere motions of breathing are known to influence vital functions of the lungs, including their development in babies, the production of air-exchange-enhancing fluid on their inner surfaces, and maintenance of healthy tissue structure. Now, new research from the Wyss Institute at Harvard University has revealed that this constant pattern of stretching and relaxing does even more—it generates immune responses against invading viruses.