Ivana Kottasová and Krystina Shveda wrote this article in CNN:

When South African scientists announced they had detected a new coronavirus variant with a worryingly high number of mutations, they were applauded for how quickly they were able to spot it.

The country was praised for having a robust genomic sequencing program, which allowed them to identify the potentially worrying properties of the variant now known as Omicron.

When viruses spread through populations, they mutate. Most mutations don't significantly alter a virus' behavior, but some can be concerning. Genomic sequencing involves decoding the genetic material of a virus to spot the mutations and determine what effect they might have on the virus -- for example whether they could make it more transmissible or more dangerous in terms of the severity of the illness it can cause.

The process is done in a lab, separately from coronavirus testing. It can take anywhere between a few hours to several weeks -- and each country has a different approach.

Sequencing efforts around the world leave much room for improvement, but South Africa's discovery of the Omicron variant is an example of how focused efforts can make a big difference.