Most respiratory viruses often have a target - a specific section of the respiratory tract. For example, respiratory syncytial virus (RSV) in young children causes damage to the lower sections (bronchi and bronchioles). It develops gradually, and because of this, according to Valentin Kovalev, the parents get the impression that the infection has “descended”, that is, it began with a runny nose and coughing, and after a few days it turned into bronchitis or bronchiolitis with severe shortness of breath. Usually complications in the later stages of SARS are caused by bacteria. Most often it is pneumonia, otitis media, bacterial sinusitis caused by pneumococcus, Haemophilus influenzae type B, or mycoplasma. The only thing that can be done to prevent such complications is to get vaccinated against what there are vaccines for: against pneumococcus and Haemophilus influenzae.