Introduction
Upper respiratory tract diseases and colds in the first place (common cold) are considered trivial diseases, which, almost inevitably, are encountered seasonally in winter/cold periods.
In most cases, they run benevolently, with self-resolution in five to seven days.
However, serious complications may be present, especially in elderly or chronically ill subjects; or there may be viral variants of greater aggression (SARS-CoV; MERS-CoV; SARS-CoV-2)
However, even if only considering the most cases, i.e. those with a benevolent course, the social and economic impact is remarkable.