COVID-19

Abstract

Coronavirus disease 19 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus which emerged in Wuhan, China in 2019, and from there spread to other parts of mainland China and around the world. The virus spreads mainly through respiratory droplets produced when an infected person coughs, sneezes, or speaks. On average, the time from exposure to SARS-CoV-2 to the appearance of symptoms is 5–6 days but can range from 1–14 days. Asymptomatic infections with SARS-CoV-2 can occur. In those with symptoms, most people (approx. 80%) will experience a mild to moderate respiratory illness and recover without hospital management. Adults 65 years of age and older, and individuals of any age with underlying medical conditions, are at increased risk for severe COVID-19 and death. Complications include respiratory failure, acute respiratory distress syndrome, sepsis/septic shock, thromboembolism, multiorgan failure and death. In rare cases, children and adults can develop a severe inflammatory syndrome a few weeks after SARS-COV-2 infection. Vaccines are available to help prevent COVID-19 disease; by August 2021, 7 vaccines had been authorized for use by the WHO to prevent COVID-19 caused by SARS-CoV-2, with others approved by country regulatory authorities.