**1. Introduction**

SARS-Cov-2 (severe acute respiratory syndrome coronavirus 2; henceforth referred to as COVID-19) is a strain of coronavirus that can infect humans, attacking the lungs and causing symptoms ranging from those of the common cold to those of severe acute respiratory syndrome (SARS) [1]. While approximately 80% of those who are infected recover with no special treatment (i.e., they are either asymptomatic or suffer from mild pneumonia) [2], recent data have confirmed that older persons (60+ years old) [3] and persons with certain pre-existing medical conditions are more likely to develop serious respiratory distress that can lead to death (3–4% of the population) [4]. COVID-19 spreads very easily between persons and, at the time of writing, no drugs or biologics have proven effective for preventing or treating the virus [5,6].

COVID-19 was first identified in the Chinese region of Wuhan in December 2019 [6]. Between December 2019 and April 2020, the virus spread throughout the world, causing more than 5,000,000 infections and over 300,000 deaths [7]. On 11 March 2020, the World Health Organization (WHO) declared COVID-19 a pandemic [8]. To contain the number of victims and prevent the collapse of the healthcare system, most national governments imposed strict restrictions on residents' freedom, forcing those infected with the virus to self-isolate and requiring all residents (infected or not) to stay at home and move through public areas only for reasons of absolute necessity. Among Western governments, the Italian government was the first to apply such restrictions [9].
