As the highly transmissible variant of the coronavirus continues its frenetic spread around the world, a new subvariant has been detected in dozens of countries.
Omicron was first reported by South Africa in November and has since replaced the Delta variant in most countries as the most prevalent strain.
The dominant form of Omicron, known as BA.1, continues to account for the vast majority of confirmed new COVID-19 infections globally, but another subvariant, known as BA.2, has begun to outcompete it in some places.
Some early studies have shown BA.2 appears to be more transmissible than the dominant BA.1 subvariant – leading scientists to ramp up their investigations.
The BA.1 version has caused the highest number of Omicron COVID-19 cases globally. As of January 31, BA.1 comprised 96.4 percent of sequences submitted to the Global Initiative on Sharing All Influenza Data, the WHO reported.
According to the director of the UCL Genetics Institute in London, Francois Balloux, BA.1 and BA.2 are some 20 mutations apart– a change in DNA sequence that leads to genetic variation.
Moreover, BA.2 has been dubbed as the “stealth variant”, as it lacks a genetic deletion on the spike protein, part of the virus that enters human cells making it harder to track using polymerase chain reaction (PCR) testing.
The BA.2 strain was first reported in South Africa in November. According to the WHO, it has since been detected in at least 57 countries as of January 31.