Global Spread of Omicron, New Variant of Concern
November 29, 2021
The first known confirmed Omicron (B.1.1.529) infection was from a specimen collected on November 9, 2021. The variant quickly became a new variant of concern because of its rapid spread in South Africa and globally, as well as the large number of mutations found in the spike protein (1). Many countries are imposing travel bans on Southern African countries.
Currently, little data are available for its transmissibility and capability of evading our immune defenses. Strikingly, the spike protein contains several mutations (at least 32 with key mutations: K417N, N440K, G446S, S477N, T478K, E484A, Q493K, G496S, Q498R, N501Y, Y505H, and P681H). Some mutations are also found in other variants of concern, which can impact PCR tests for diagnostics, therapeutics, increase transmissibility, improve binding affinity to host receptor ACE2, and enable the virus to partially escape host immunity. Other mutations may also affect viral transmissibility and disease severity, yet it is still unclear. According to epidemiology data, the variant has been detected at faster rates than previous surges in South Africa, suggesting that this variant may have a growth advantage. In two weeks, spread of the omicron variant has resulted in rapid growth of new confirmed cases (2,828 cases) in South Africa (2). Furthermore, the virus is changing the demographic profile of patients with COVID-19 by causing moderate to severe diseases in young South Africans (in their 20s and late 30s). Preliminary evidence suggests there may be an increased risk of reinfection with Omicron (3). A low vaccination rate in the country is also facilitating the spread of virus and infection in unvaccinated people. Efficacy of the vaccines against this new variant is unknown. Currently, limited data are available for breakthrough infection. However, vaccines remain critical to reducing severe disease and death against other circulating variants.
Global surveillance is tracking the spread of virus. In addition, GVN scientists are diligently analyzing and characterizing this variant (i.e., efficacy of vaccine and therapeutics, viral transmissibility, and disease severity). The GVN will disseminate their results as soon as possible. SARS-CoV-2 variants keep emerging during this prolonged pandemic, and they are significantly affecting our effort to mitigate the virus. The ongoing pandemic has taught us an important lesson: We must continuously make our best effort to minimize our chances of getting infected with any variants, by both vaccination and other non-pharmaceutical interventions, such as physical distancing and mask wearing. Importantly, it is critical to increase our efforts for global COVID-19 vaccination to end this pandemic.