Models of respiratory infections: Virus-induced asthma exacerbations and beyond

Respiratory infections are one of the main health problems worldwide. They are a challenging field of study due to an intricate relationship between the pathogenicity of microbes and the host's defenses. To better understand mechanisms of respiratory infections, different models have been developed. A model is the reproduction of a disease in a system that mimics human pathophysiology. For this reason, the best models should closely resemble real-life conditions. Thus, the human model is the best. However, human models of respiratory infections have some disadvantages that limit their role. Therefore, other models, including animal, in vitro, and mathematical ones, have been developed. We will discuss advantages and limitations of available models and focus on models of viral infections as triggers of asthma exacerbations, viral infections being one of the most frequent causes of exacerbating disease. Future studies should focus on the interrelation of various models.