Coronovairus Covid-19 (SARS-COV-2)

SARS-CoV-2 is a virus of the subfamily Orthocoronavirinae, of the family Coronaviridae to which belong viruses responsible for a variety of diseases ranging from the common cold, to MERS, to SARS. Its morphology is formed by viral spikes, glycoproteins that cross the pericapsid, called S proteins, with hemagglutinating and fusion properties. A protein coating consisting of the M (matrix) protein is interposed between the nucleocapsid and pericapsid. There are seven viruses belonging to this family capable of infecting humans. They all cause respiratory diseases, including colds, pneumonia and bronchitis, but three in particular cause very serious and sometimes fatal respiratory infections:

• Sars-Cov 2: a new coronavirus identified as the cause of coronavirus disease in 2019 (COVID-19) that started in Wuhan, China, in late 2019 and has spread worldwide;
• Mers-CoV coronavirus identified in 2012 as the cause of Middle East respiratory syndrome (MERS);
• Sars-CoV identified in 2003 as the cause of a severe acute respiratory syndrome outbreak that began in China in late 2002.

Like other Coronaviruses, SARS-CoV-2 is probably zoonotic: that is, it develops in animals and is later transmitted to humans. Despite several hypotheses that have been made, it has not yet been possible to identify incontrovertibly the animal responsible.
Transmission then occurs directly between humans, typically by direct contact or through infected particles (droplets) emitted during respiration. Contagion by indirect route, following contact with contaminated materials and surfaces, is also possible.

Since its first detection in December 2019 in China, COVID-19 has rapidly spread across the planet, causing a pandemic that is still ongoing. In two years, it has caused more than 530 million confirmed cases and more than 6 million deaths.

The disease has variable symptoms depending on the severity and condition of the patient, ranging from asymptomatic to extremely severe.
The incubation period averages 2 to 7 days, up to a maximum of 14 days.
In general, the most common symptoms are comparable to those of influenza: fever, cough, sore throat, weakness, fatigue, and muscle pain, to which can also be added loss of taste and smell, headache, muscle pain, vomiting, and diarrhea. More severe cases can present with pneumonia, acute respiratory distress syndrome, and other complications, all of which can be life-threatening.

Because of the nonspecificity of much of the symptoms, diagnosis is mainly made by two means: serologic tests, which measure the presence of antibodies following infection, and tests based on PCR techniques, which detect the presence of virus components in the body.

There is no approved therapy for COVID-19, as indeed there is for other Coronavirus diseases. In most cases, the disease resolves spontaneously after about a week, and and treatment focuses on support for symptom management and maintenance of vital status, with administration of antipyretics and analgesics, maintenance of hydration, and respiratory support by mechanical ventilation or extracorporeal oxygenation.
Some level of success has been achieved with the use of monoclonal antibodies, specific proteins that bind to the virus and facilitate its identification by the immune system.

The main tool to prevent the circulation of the virus and the most severe cases of the disease is vaccination. Developed in an unprecedented global effort, four specific, highly effective and safe vaccines are used in Italy: Comirnaty (Pfizer-BioNTech), Spikevax (Moderna), Vaxzevria (AstraZeneca) and Janssen (Johnson&Johnson). In addition to the vaccine, practices are recommended to reduce the possibility of exposure to the virus, such as wearing masks, distancing oneself from other people, and using disinfectants to remove viruses on hands and surfaces, to which isolation and quarantine have been added at peak times.A graphic detail of the physical composition of the virus, can be found on the University Vita - Salute San Raffaele website, at this link dedicated to the structure of Sars-Cov-2,