are Y145H and A222V. Both the types have been consistent in several other SARS-CoV-2 lineages since the advent of the pandemic, but at a lower frequency to date.
“The first strains carrying both mutations were sequenced in April 2020. Neither are found in any ‘variant of concern’,” says Francois Balloux, Professor of Computational Systems Biology and Director, UCL (University College London) Genetics Institute in a statement released on 19 October 2021.
Distribution of Delta Variant
The first sample of the Delta variant in India was identified in May 2021. Among the 17 new AY.4.2. samples, 7 were found in Andhra Pradesh, four in Kerala, two each in Karnataka and Telangana, & one each in Jammu and Kashmir and Maharashtra, as per the data by GISAID, an open-access genomic database of influenza viruses and the coronavirus.
Almost 18,207 sequences of AY.4.2 worldwide have been reported by the GISAID database, among which the UK alone contained 16,891 sequences. However, the variant has not been detected in over 68,000 SARS CoV 2 samples in India when explored through whole-genome sequencing under the INSACOG project.
Hence, the COVID genomic surveillance project of India is now on high alert since the sub-lineage of SARS CoV 2’s Delta variant was detected in the country along with global cases in the UK (last week) and the USA.
Potency of AY.4.2
The UK Health Security Agency declared that the country witnesses daily peak of COVID-19 cases globally after the USA with the spread of a new subtype of Delta variant. The new variant accounts for 6% of all SARS CoV2 genetic sequences in the last week of September with a growth trajectory.
Scientists believe that the new variant might be more infectious than the Delta strain, almost 10% more transmissible and thus the AY.4.2 has now been declared as the ‘variant under Investigation’ in the UK.
“However, we will raise surveillance and more samples will be tested from among the international passengers in the coming daysso that we don’t miss the possible infections caused due to AY 4. 2 and those infected are quickly identified,” says a senior official attached with the National Centre for Disease Control, which is leading INSACOG.
Concern on New Variant
The UK Health Security Agency (UKHSA) thereby dubs the new variant as “Delta Plus” (now named VUI-21 OCT-01), as it reaches a faster spread than the dominant Delta variant.
So far, other countries like Madhya Pradesh and Indore have also witnessed the rising trend of the new variant as per genome sequencing report from the National Centre of Disease Control (NCDC).
Among seven infected cases in Indore, two were Army officers posted in the Mhow Cantonment (as per Indore chief medical and health officer Dr BS Saitya). Moreover, since August, the sub-lineage resulted in a 64% escalation in COVID cases in September as per the NCDC report.
“The designation was made on the basis that this sub-lineage has become increasingly common in the UK in recent months, and there is some early evidence that it may have an increased growth rate in the UK compared to Delta. More evidence is needed to know whether this is due to changes in the virus’ behaviour or to epidemiological conditions,” says UKHSA (UK health security agency).
Variant Under Investigation
Although anticipation of the heightened risk of the AY.4.2 variant hovers over the public, there is no definitive evidence on their transmissibility. There have also not been any reports on amplified death risk or severity of infection due to the AY.4.2 variant in the UK.
Hence, the strain is not yet designated as a ‘variant of concern’ by the WHO. In addition, scientists also state that it might not be necessary that a more transmissible variant may necessarily cause a greater concern of being dangerous/virulent.
Source: Medindia
