Delta sub-lineage AY.12 seen in states; needs closer examination: INSACOG

AY.12, a sub-lineage of Delta which is driving fresh cases in Israel, is being seen in many states in the country but the numbers need a closer examination, INSACOG has said in its latest bulletin

AY.12, a sub-lineage of Delta which is driving fresh cases in Israel, is being seen in many states in the country but the numbers need a closer examination, INSACOG, a genome sequencing consortium, has said in its latest bulletin.

The INSACOG said functional impact of the changes between Delta and AY.12 is not known but the two appear to be very similar at a molecular level.

"Delta variant is the major VOC in India at this time. AY.12, a reassigned sub-lineage of Delta is being seen in many states, but the numbers need closer examination," the INSACOG said in its bulletin dated August 23.

The reclassification is primarily to assist micro-epidemiology and is not based on acquisition of significant mutations, it noted.

It is not currently known whether AY.4-AY.12 are clinically different from Delta.

AY.12 has lost some of the mutations seen in Delta parent lineage, including G142D in spike protein. No new mutations of concern are noted in the spike protein, it said.

However, Delta continues to remain a dominant variant driving infections in many countries.

"Delta continues to expand around the world with Israel seeing new cases rising to near previous highs despite about 60 per cent of the population being fully vaccinated

"AY.12 is the dominant lineage in Israel and is one of the reclassified Delta sub-lineages. However, its rapid growth in Israel means that it should be examined further," the INSACOG said.

AY.1, AY.2 and AY.3 are classified as Delta Plus variants. However, at this time none of these sub-lineages has been found to have a growth advantage over the Delta parent lineage, it noted.