COOVID-19: What have we learned since the beginning of the epidemic until today?

Abstract

In late December 2019, in the city of Wuhan, in China, the appearance of unknown viral pneumonia was recorded in a large number of patients. The cause of this infection was soon discovered - a new coronavirus, called SARS-CoV-2, due to its genetic similarity to the virus that causes severe acute respiratory syndrome (SARS-CoV). The infection then spread rapidly to other continents, and the pandemic is still ongoing. The clinical presentation varies from the asymptomatic form to symptoms of upper respiratory tract infection, and finally to pneumonia and acute respiratory distress syndrome (ARDS). The elderly, immunocompromised patients, and patients suffering from chronic, internal medicine diseases are at risk of the severe form of the COVID-19 disease. The virus enters cells via angiotensin converting enzyme 2 (ACE2) receptors, which are present in practically all tissues in the body. In addition to interstitial pneumonia, pathological changes are also found in other organ systems. The first case in Serbia was recorded on March 6, 2020. A large number of patients required the engagement of health workers of all profiles as well as the introduction of a large number of health institutions into the COVID system. The emergence of a new virus necessitated a new antiviral drug. Based on previous experience with the SARS-CoV virus, previously known antiviral drugs have been used, with varying degrees of success. The therapy changed in accordance with new knowledge, and since the beginning of the epidemic in Serbia, the National Protocol of the Republic of Serbia for the Treatment of the COVID-19 Infection has been established, which has kept apace with the recommendations of the world's leading institutions. The most significant event during the pandemic was the development of the vaccine against COVID-19, with vaccination in Serbia beginning in December 2020. How quickly the epidemic will end depends directly on the speed and efficiency of vaccination, along with other epidemiological measures.