Centre asks states to keep an eye on emerging COVID-19 clusters as BA.4, BA.5 detected from random samples

As India’s COVID-19 genome surveillance project confirms the presence of Omicron subvariants, BA.4 and BA.5, in the country, the Centre has asked states to keep an eye on potential clusters of coronavirus infections and disease severity patterns based on hospitalisation rates.

The BA.4 and BA.5 variants were found to lead a fifth wave of COVID-19 in South Africa recently before being detected in several other countries.

The instructions come as India reported 2,124 new COVID-19 cases on May 24, over 26 percent more than the infection reported on the previous day, while active cases, too, increased on the second consecutive day.

In a bulletin dated May 21, which was released on May 23, the Indian SARS-CoV-2 Genomics Consortium (INSACOG) said that a 19- year-old female in Tamil Nadu has been found infected with the BA.4 variant of SARS-CoV-2.

“The patient has shown only mild clinical symptoms and has been fully vaccinated. The patient had no travel history. Before this, a South African traveller was reported positive for the BA.4 variant on arrival at Hyderabad airport,” the bulletin said.

The bulletin added that an 80-year-old man in Telangana tested positive for the BA.5 variant. This patient, too, was fully vaccinated and had no travel history. He was only mildly symptomatic, according to INSACOG. It added that contact tracing of patients detected with BA.4. and BA.5 is being undertaken as a precautionary measure.

“These variants have not been associated with disease severity or increased hospitalisation,” the project led by the National Centre for Disease Control under the Union health ministry clarified.

Omicron subvariants already in the community

Scientists attached with INSACOG said that as patients with the new subvariants have been found without any international travel history, it suggested community transmission of these strains already.

“These subvariants have been found in random samples sent by states for whole genome sequencing and they show that these strains are already circulating in the community,” said an INSACOG scientist.

Previously, the consortium has also confirmed the presence of BA.2.12.1 in India. This strain was leading a surge in COVID-19 cases in parts of the US in April.

No major concern for India

Experts, meanwhile, sought to allay fears related to a possible surge in cases in India but underlined the need to remain vigilant.

“There are no major concerns based on what we know so far as most people in India have both recovered from the infection as well as have been vaccinated. This ensures that the risk for severe disease in the country is among the lowest worldwide,” said Anurag Agarwal, a biologist with Ashoka University. Till recently, he headed the CSIR-Institute for Genomics and Integrative Biology, an INSACOG partner.

“Further we had a recent BA.2 wave, and BA.4 and BA.5 are antigenically closer to BA.2 than BA.1,” he said, referring to the omicron wave in India in January this year, in which BA.2 was the dominant strain.

Immunologist Dipyaman Ganguly, who is attached with the CSIR-Indian Institute of Chemical Biology, said that genetic surveillance is always necessary not only to track BA.4 or BA.5, but also to keep a vigil for new variants.

“But public scare is not justified with regard to BA.4 or BA.5, as the clinical features associated with these variants are far from too severe,” he said.