Omicron Variant of the SARS-CoV-2 Virus is highly transmissible. The most common form that is causing the infection is BA.1 and now there is a new variant, a close cousin to it, known as BA.2. In addition to BA.1 and BA.2, the WHO lists two other subvariants - BA.1.1.529 and BA.3.

World Health Organization Director-general, Tedros Adhanom Ghebreyesus said, "It's premature for any country either to surrender or to declare victory. This virus is dangerous, and it continues to evolve before our very eyes. WHO is currently tracking four sub-lineages of the Omicron variant, including BA.2."

WHO technical lead for Covid-19, Maria Van Kerkhove: "There's no indication that there's a change in severity. Again, omicron overall we know is more transmissible, it has more growth advantage and causes less severe disease than Delta. But it's still a very dangerous virus."

BA.1 and BA.2, the two lineages of Omicron differ from one another by over 40 point mutations. BA.2 was initially discovered in early December in South Africa.

According to a Danish study that analysed infections in more than 8,500 Danish households between December and January said BA.2 is more transmissible than BA.1 and is more capable of infecting vaccinated people.

Van Kerkhove: "We need people to be aware that this virus is continuing to circulate, and it's continuing to evolve."

WHO officials said people should get vaccinated and should wear masks and follow social distancing to contain the spread of coronavirus.