Viral infections of the upper and lower respiratory tracts are among the most common illnesses in humans. They occur mainly in children and infants, who can experience up to five to six episodes in any given year (Berry et al., 2015). For this reason, acute respiratory infections (ARIs) represent a persistent public health problem. Although the majority of ARIs remain confined to the upper respiratory tract (rhinosinusitis, pharyngitis, laryngitis, and tracheitis), they can cause severe manifestations when they affect the lower respiratory tract (bronchitis, bronchiolitis, and pneumonia) (Bicer et al., 2013; Tregoning and Schwarze, 2010; Zappa et al., 2008).
