THE SARS-CoV-2
The family of coronaviruses is common across the world in animals and humans. These viruses generally are transmitted by droplets and cause the common cold. Occasionally they are responsible for more severe diseases like the Middle East respiratory syndrome and the SARS, both of which often lead to pneumonia.
The illness caused by SARS-CoV-2, a new strain of coronavirus not previously seen in humans, has been named COVID-19 (COVID-19: CO = corona; VI = virus; D = disease; 19 = year of outbreak) [1].
Because SARS-CoV-2 is a new virus, the lack of immunity in the population and the absence of an effective vaccine explain its worldwide spread. On 31 December 2019, Chinese authorities notified the World Health Organization (WHO) of an outbreak of pneumonia in Wuhan City, which was later classified as a new disease (named COVID-19), whereas 1 month later the WHO declared the outbreak of COVID-19 a ‘Public Health Emergency of International Concern’, and finally designated it a pandemic on 11 March 2020 [2].