Omicron subvariant detected in substantial fraction in India

The INSACOG, in its latest bulletin, said while most Omicron cases in the country so far have been asymptomatic or mild, hospitalisations and ICU cases have increased in the current wave and the threat level remains unchanged.

“Omicron is now in community transmission in India and has become dominant in multiple metros, where new cases have been rising exponentially. BA.2 lineage is in a substantial fraction in India and S gene dropout based screening is thus likely to give high false negatives,” the INSACOG said.

S-gene drop-out is a genetic variation like that of the Omicron variant.

“The recently reported B.1.640.2 lineage is being monitored. There is no evidence of rapid spread and while it has features of immune escape, it is currently not a variant of concern. So far, no case has been detected in India,” the INSACOG said.

It also said that Omicron is now in community transmission in India and has become dominant in Delhi and Mumbai where new cases have been rising exponentially.

Omicron wave continues to expand globally, but the rate of hospitalisation during this wave is less, the bulletin added.

Omicron sub-lineage BA.2 variant throws up new virus questions

Scientists are keeping a close watch on a recently-discovered sub-variant of the Omicron version of the Covid-19 virus to determine how its emergence could effect future pandemic spread.

The initial Omicron variant has become the dominant virus strain in recent months but British health authorities have notably identified hundreds of cases of the latest version, dubbed BA.2, while international data suggest it could spread relatively quickly.

The UK Health Security Agency (UKHSA) identified over 400 cases in Britain in the first ten days of this month and has indicated the latest variant has been detected in some 40 other countries, accounting for a majority of most recent cases in some nations including India, Denmark and Sweden.

The UKHSA indicated it had designated the BA.2 sub-lineage as a variant under investigation (VUI) as cases of it were on the increase even if, in Britain, the BA.1 lineage currently remains dominant.

BA.2 has yet to be designated a variant of concern — but French epidemiologist Antoine Flahault says countries have to be alert to the latest development as scientists ramp up surveillance.