BA.4 was first detected from a specimen collected on 10 January 2022 in Limpopo, South Africa
As per reports, one case of Omicron BA.4 variant has been found in Hyderabad, Telangana. "Scientists associated with the Indian SARS-CoV-2 Consortium on Genomics (INSACOG) said that from India, details of BA.4 subvariant were entered on GISAID, a global science initiative that provides open access to genomic data of influenza viruses and the coronavirus responsible for the COVID-19 pandemic, on 9 May," a news report says.
The BA.4 variant of the Omicron has been in the radar of health experts along with the BA.5 variant since the beginning of this year. These latest variants on the watchlist of the health experts are notorious for infecting a large number of the population in South Africa.
The National Institute for Communicable Diseases (NICD), South Africa refers to these variants as Omicron viruses with a new combination of mutations.
What are the BA.4 and BA.5 variants?
"In terms of their mutations, BA.4 and BA.5 share mutations across their genomes with both BA.1 and BA.2 (also lineages of Omicron), but are most similar to BA.2," says NICD, and adds, "BA.4 and BA.5 differ from one another in mutations that are outside of the spike gene but they are identical to each other in terms of spike mutations (1,2). For this reason, they are often discussed together."
While the BA.4 was first detected from a specimen collected on 10 January 2022 in Limpopo, the BA.5 Omicron lineage was first spotted from a specimen collected on 25 February 2022 in KwaZulu-Natal.
Both lineages have been detected in countries outside South Africa, such as the USA, UK, and Botswana.
As per reports, on May 9 details of BA.4 subvariant were entered on GISAID by India. Scientists associated with the Indian SARS-CoV-2 Consortium on Genomics (INSACOG) have confirmed this to the media.
What about their immune evasion capability?
"The recently emerged SARS-CoV-2 Omicron sublineages BA.2.12.1, BA.2.13, BA.4 and BA.5 all contain L452 mutations and show potential higher transmissibility over BA.2," says a research study.
Another study says that the antibodies produced from the Omicron BA.1 attack are less likely to work against BA.4 and BA.5. The study found that the immunity from Omicron BA.1 variant drops around 7.5 fold with the new Omicron BA.4 and BA.5 variants,
Several studies have drawn the conclusion that the new variants of Omicron are better than the parental strain in dodging immunity.
Can BA.4 and BA.5 variants cause severe infections?
The study that found a 7.5 fold decrease in recognition by antibodies of BA.1 for BA.4 and BA.5 has concluded that based on neutralization escape, BA.4 and BA.5 have potential to result in a new infection wave.
The European Centre for Disease Prevention and Control (ECDC) has already designated the BA.4 and BA.5 Omicron sub variants as variants of concern (VOC) and said these variants could increase infection rates in the region in the weeks and months ahead.
Are there any specific symptoms associated with BA.4 and BA.5?
Experts at NICD, South Africa say that distinct symptoms of BA.4 and BA.5 variant infection has not come to fore. The experts believe that since these are the variants of the Omicron, they are not a different coronavirus variant and infer that the symptoms are likely to be similar as other variants of Omicron.
Different strains of coronavirus have shown distinct symptoms. While loss of smell and taste was mostly found in people during the Delta wave, sore throat was a common symptom seen in patients during the Omicron led third wave of COVID.
Variations within different variants of the same strain of coronavirus have not been found till now.
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