WHO investigating new coronavirus variant

A little under three months since the world was swept by the Omicron variant of Covid-19, a new version of that variant, called BA.2, is gaining ground in some countries, notably India and Denmark.

The World Health Organization (WHO) has once again recommended that scientists begin investigating the characteristics of BA.2, a descendant of Omicron, to determine whether it poses new challenges.

“The BA.2 descendent lineage, which differs from BA.1 in some of the mutations, including in the spike protein, is increasing in many countries,” WHO said on its website.

“Investigations into the characteristics of BA.2, including immune escape properties and virulence, should be prioritised independently (and comparatively) to BA.1”.

There is no evidence now that BA.2 is more virulent, spreads faster, or escapes immunity better than the original Omicron variant coded BA.1 by virologists.

However, early detection of such variants helps public health experts better identify which variants pose the most danger to people’s health, and therefore require more stringent mitigation measures.

BA.2 has been detected in the UK, Germany, India, and Denmark, among other countries, according to health officials and media reports abroad.

BA.2 has also been picked up in South Africa.

Most Omicron cases have been caused by variants known to scientists as BA.1. But in several countries, the proportion of cases caused by BA.2 is increasing rapidly and quickly replacing BA.1.

BA.2 has 32 of the same mutations as BA.1, but it also has 28 that are different. Back in November, when scientists in South Africa and Botswana discovered Omicron, they did not find just one version but three, called BA.1, BA.2, and BA.3 by the Phylogenetic Assignment of Named Global Outbreak Lineages at the University of Edinburgh.

Like other viruses, SARS-CoV-2, the virus that causes Covid-19 disease, changes or mutates constantly, mostly in harmless ways.

As a virus spreads and replicates, it naturally picks up random mutations that can change how it behaves, such as how contagious it is or how severely it can make people ill – although many mutations won't change how the virus affects humans.

According to the Statens Serum Institut, Denmark’s infectious disease surveillance entity, the sub-variant is 1.5 times more transmissible than the original Omicron strain or BA.1.

Although it is too soon to know, there are concerns that the specific mutations identified with the BA.2 subtype could make it more contagious or better able to evade vaccines – two factors that had already enabled Omicron to spread so pervasively around the world.