The first possible case of an infection with the BA.4 variant of the Sars-CoV-2 has detected in India, people involved in the genome surveillance of the coronavirus have said, adding that it does not yet pose a concern since it is an offshoot of the Omicron variant, which has already spread widely in the country, Hindustan Times reported.
The Indian SARS-CoV-2 Genomics Consortium (INSACOG) in its latest bulletin said the BA.2 variant continues to be dominant in India. “BA.2.10 and BA.2.12 are BA.2 sub-lineages that have been detected and many old BA.2 sequences have been reclassified into these new sub-lineages. So far these sub-lineages are not reported to be associated with increase severity of disease,” said INSACOG in its latest bulletin on results of genome sequencing.
According to data submitted to GSAID during the past four weeks, 773 samples were of the Omicron variant, making it about 97.2% of the total submitted samples of the said variant. “Suspected recombinant sequences are under further analysis,” said the consortium in the bulletin.
The BA.4 variant was detected earlier this month detected in Hyderabad in samples taken from a traveller from South Africa, where this strain of Omicron has been causing the current Covid-19 wave, people aware of the matter said, adding that this information is subject to an official confirmation.
The European Centre for Disease Prevention and Control (ECDC) last week designated the BA.4 and BA.5 Omicron subvariants as variants of concern (VOC) and said they could fuel increases in infections, with a 12% to 13% growth advantage over the Omicron’s BA.2 sub-lineage.
“It is the Omicron variant after all; there may be spikes here and there, which are likely going to be transient ones. Therefore, as of now it does not look like a cause for major concern,” said the official, who is part of Insacog, asking not to be named.
BA.4 and BA.5 were first detected in South Africa. The BA.4 variant was first detected from a specimen collected on January 10, 2022 in Limpopo, South Africa, and BA.5 was first detected on February 25, in KwaZulu-Natal.
While both are sub-lineages of the Omicron variant, the two new VOCs have more in common with the BA.2 lineage than BA.1, which was more widespread in South Africa.
Experts said high transmissibility should not worry as much as higher hospitalisation rates and deaths.
“The concern is high hospitalisation and death rate for any new variants; however in the Omicron wave we have seen fewer hospitalisations and deaths, which seems to tell us that was some protection against severe disease at the population level likely because of the hybrid immunity due to vaccination and natural infection,” said Dr Gagandeep Kang, senior vaccine expert and faculty, Christian Medical College, Vellore (Tamil Nadu).
“RNA viruses have high mutation rates but not all mutations are of serious concern. It is ok if transmissibility is on the higher side but hospitalisations and deaths are not increasing. One needs to look at clinical implications,” she added.
Among other major variants that are currently in circulation as per the whole genome sequencing of samples, delta and kappa have higher presence, with about 1.5% and 0.5% of the samples returning positive for the respective strains, the Insacog data showed.