SARSCoV2

SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, is the virus that causes the illness COVID-19. It is an enveloped, positive-sense single-stranded RNA virus in the family Coronaviridae, genus Betacoronavirus, subgenus Sarbecovirus. The genome is about 29.9 kilobases in length. The virus uses its spike glycoprotein to bind the angiotensin-converting enzyme 2 (ACE2) receptor on human cells and is primed by host proteases, enabling entry and replication inside the cytoplasm.

SARS-CoV-2 spreads mainly through respiratory droplets and aerosols, especially during close contact. Asymptomatic and presymptomatic transmission contribute to the spread of infection. The incubation period is typically 2 to 14 days. The clinical spectrum ranges from asymptomatic infection to mild respiratory illness, pneumonia, acute respiratory distress syndrome, and, in severe cases, organ failure. Risk factors for severe disease include advanced age and certain underlying health conditions. Public health responses have included vaccination, masking, ventilation improvements, testing, and contact tracing.

Origin and impact: The virus was identified in late 2019 in Wuhan, China, and rapidly achieved global spread, leading to a prolonged pandemic with substantial health, social, and economic effects. The virus has diversified into multiple lineages; several variants of concern have emerged with mutations in the spike protein that affect transmissibility and immune recognition.

Vaccines and treatments: Multiple vaccines have been authorized globally, including mRNA vaccines, viral-vector vaccines, and inactivated vaccines, which reduce the risk of severe disease and death. Antiviral drugs and monoclonal antibodies have been used to treat certain infections and high-risk patients, alongside supportive care.