Severe acute respiratory syndrome coronavirus 2 Omicron variant (SARS-CoV-2 Omicron) (SARS-CoV-2 Omicron)

The SARS-CoV-2 Omicron virion (B.1.1.529) is a highly mutated variant of the severe acute respiratory syndrome coronavirus 2, first identified in late 2021. It is characterized by more than 30 mutations in the spike protein alone, which significantly increases its transmissibility and capacity for immune evasion compared to previous variants (World Health Organization, 2021). The virion's primary biological function is to infect host cells by utilizing its spike protein to bind to the human angiotensin-converting enzyme 2 (ACE2) receptor, followed by membrane fusion and the release of its viral RNA (Nature, 2022). In the context of disease, it is the causative agent of COVID-19, often presenting with altered tissue tropism, favoring the upper respiratory tract over the lower lungs in many patients (NIH, 2023). Therapeutic intervention focuses on inhibiting the virion's lifecycle through various mechanisms, including the inhibition of the 3C-like protease (Mpro) and the RNA-dependent RNA polymerase (RdRp), or by neutralizing the spike protein with antibodies (Science, 2022). A significant challenge in treating Omicron is its rapid evolution, which has led to the loss of efficacy for many previously authorized monoclonal antibodies and necessitates continuous monitoring of drug resistance (CDC, 2024).

Other names

B.1.1.529Omicron variantSARS-CoV-2 B.1.1.529SARS-CoV-2 Omicron virion

Inhibition of the viral 3C-like protease (Mpro), inhibition of the RNA-dependent RNA polymerase (RdRp), and neutralization of the spike protein to prevent viral entry into host cells (NIH, 2023; Nature, 2022).