SARS-CoV-2 Omicron variant

The Omicron variant is a form of SARS-CoV-2, the virus that causes COVID-19. It was first reported to the World Health Organization (WHO) from South Africa on 24 November 2021. On 26 November 2021, the WHO called it a variant of concern, and named it "Omicron". Omicron is a letter in the Greek alphabet.
Omicron multiplies around 70 times faster than the Delta variant in the bronchi, but it is less severe than other strains, especially the Delta variant. Omicron might be less able to enter deep lung tissue. Omicron infections are 91 percent less fatal than the delta variant, with 51 percent less risk of hospitalization.
Vaccines can protect against severe disease and hospitalisation especially after a third dose of an mRNA vaccine is given. Early data found that double vaccination give 30 to 40 percent protection against infection and around 70 percent protection against hospitalization. A recent third vaccine dose boosts effectiveness against infection to around 75 percent, and 88 percent for severe disease.