E-Paper
No Delta variant found in samples tested in Maharashtra, BA.5 on its way out: scientists
As per national data by INSACOG, delta variant samples have not been found since May this year in genome sequencing samples across India
Scientists involved in genome sequencing of samples sent for Covid testing observed that Delta variant of Covid, which caused havoc during the second wave in 2021, was not found in samples tested in Maharashtra. The scientists also observed that very soon BA.5 variant of Omicron will also be flushed out.
Dr Rajesh Karyakarte, a scientist at Indian Sars-CoV-2 Genomics Consortium (INSACOG), involved in genome sequencing work in Maharashtra, confirmed on Monday that Delta variant was not found in the genome sequencing of any samples since May this year.
As per national data by INSACOG, delta variant samples have not been found since May this year in genome sequencing samples across India.
“We can see an increase in the prevalence of the BA.2.75 subvariant in the state. However, Delta variant has been flushed out entirely by these new variants. So, there are no cases of these variants found in the samples,” said Dr Karyakarte.
The second wave claimed around 89,000 lives in Maharashtra with Pune being the worst affected as Delta turned out to be most dominant from April to September 2021. In Pune alone, around 18,000 people died due to Covid during the period. In the later part of the wave, the country saw some cases of Delta plus, which turned out to be milder than the original variant.
According to experts, in the second wave, only Delta variants were reported in samples. After the wave waned out, other variants started showing in the genome sequencing. Whereas since the Omicron cases were reported, Delta cases have reduced.
Earlier during its analysis, INSACOG had reported that breakthrough infections of coronavirus cases comprise a very high proportion of the Delta variant last year.
He added that as of now, the patients who have been tested with BA.2.75 subvariant have mild symptoms.
Scientists have observed that the prevalence of BA.2.75 subvariant has increased to over 50 per cent in samples tested in Maharashtra. However, Covid cases have reduced due to vaccination and immunity.
Prevalence of BA.5 prevalence in samples has decreased to less than 10 per cent. This subvariant has been reported to have caused more hospitalisation and severe infection in many countries.
“Patients have reported mild symptoms who have been tested with BA.2.75 subvariant. We have earlier seen that as the Delta variant progressed it wiped out all the other variants. When the Omicron variant started showing, it also wiped-out other variants. Similarly, now as the BA.2.75 variants prevalence is increasing, that of BA.5 is on the decrease. BA.2.75 variant is likely to flush out the BA.5 variant very soon from these samples,” said Dr Karyakarte.
Dr Pradeep Awate, state surveillance officer, said that routine genome sequencing surveillance is underway for Covid in the state across seven laboratories under INSACOG.
“The latest report also suggests that the number of patients infected with BA.2.75 subvariant is on the rise, while patients BA.2.38 variant which was earlier the dominant one, seem to be reducing. A detailed epidemiological investigation of these patients is underway. Till Monday, the state tally of BA.4 and BA.5 to 348, and that of BA.2.75 to 459,” said Dr Awate.
