India's overall COVID-19 tally now stands at 2,77,29,247 and the death toll has surpassed 3,22,000, according to the official government data.
The variant first identified in India, technically known as B.1.617.2, can now be described as "Delta" and the so called "UK variant" as "Alpha" according to a note from the organization late on Monday.
In the United Kingdom it's thought the Indian variant - or rather a particular type of it known as B.1.617.2 - could be spreading more quickly than the Kent variant, which was responsible for the surge in cases over the winter.
Under the new system, the variants of concern take on the following names: the hitherto so-called British variant B.1.1.7 becomes Alpha; the B.1.351 first discovered in South Africa becomes Beta, while the Brazilian P.1 becomes Gamma.
The B.1.617.1 variant of interest is called Kappa.
India registered record deaths due to Covid exactly a week back with 4,529 deaths - the highest number of fatalities from Covid infection in any country since the coronavirus outbreak was reported in China's Wuhan in December 2019.
The World Health Organisation (WHO) has moved - perhaps not at lightning speed - to issue some official guidance on the most unsafe "variants of concern".
It's hoped the new system will discourage stigmatising countries that detect the variants. "As a result, people often resort to calling variants by the places where they are detected, which is stigmatising and discriminatory".
A surge in Glasgow may also be driven by the variant.
Besides these names, there are two other scientific names in use for each mutation, while different geographic names have been used to describe the same variant.
"It would have been good to have thought about this nomenclature early", Dr Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, told CNN. However, only 20 crore doses have been administered so far and just above 3% of the Indian population has been fully vaccinated.