SARS Cov 2 Omicron

About SARS Cov 2 Omicron

The Omicron variant of SARS-CoV-2 was first identified in South Africa and Botswana in November 2021 and designated a Variant of Concern by the WHO on November 26, 2021. Omicron had about 50 mutations compared to the original strain, more than 30 of them in the spike protein, including around 15 in the receptor binding domain. This level of mutation suggested the variant may have evolved in an immunocompromised individual with chronic infection. Omicron spread faster than any previous variant, reaching 77 countries within 3 weeks. While Omicron caused less severe disease on average, the sheer number of infections overwhelmed health systems. The variant partially escaped vaccine induced immunity, though additional vaccine doses restored substantial protection against severe disease. Sub variants including BA 2, BA 4, BA 5, XBB, and JN 1 successively replaced each other. Omicron infected more people in a few months than previous variants did in 2 years. South Africa was praised for rapid identification and transparent reporting.