Scientists have detected cases of a new variant of SARS-CoV-2, which is the virus that causes COVID-19, in a number of countries. Omicron (B.1.1.529) has an unprecedentedly large number of mutations in the part of its genome that encodes a key section of its spike protein, which the virus uses to infect host cells. This suggests that Omicron may be able to evade some of the immune protection afforded by vaccines, many of which are based on the original spike protein, and past infections.
On November 16, 2021, there were 136 daily recorded cases of COVID-19 in South Africa. By November 25, 2021, that number had risen to over 1,200.
More than 80% of these cases were in the densely populated province of Gauteng, which includes Johannesburg and Pretoria.
Researchers estimated that the R-value, which is the average number of new cases caused by each infection, was 1.47 for South Africa as a whole.
If R is more than 1, an outbreak will grow exponentially. In Gauteng province, R was 1.93.
Scientists at the Centre for Epidemic Response and Innovation (CERI) in Stellenbosch, South Africa, believe that a new variant of the virus known as Omicron (B.1.1.529) is responsible for these worrying figures.
There have been three previous peaks of infection in South Africa during the course of the pandemic, with the third due to the Delta variant. The latest surge coincides with the first detection of Omicron by scientists.
Scientists have sequenced around 100 confirmed cases of Omicron infection in South Africa. Most of the cases have been in Gauteng.
The new variant is also present in Botswana, Hong Kong, Europe, Canada, Israel, Japan, the United States, and elsewhere.

covid-19:-why-the-omicron-variant-has-scientists-worried