BF.7 not variant of concern in India, claim experts

Though the highly-transmissible BF.7 variant is driving up Covid spread in China, it is not a concern for India, experts have said.

BF.7 is a sub-lineage of the BA.5 sub-variant of Omicron. Dr Giridhar Babu, TAC member and epidemiologist, said that the transmission rate and severity of a variant are not uniform everywhere; it varies depending on the susceptibility of the local population.

“Since China followed a zero-Covid strategy, most people there are not exposed to other variants, and are susceptible,” said Dr Babu. “Besides, the indigenous Chinese ‘inactivated vaccines’ have not shown as much efficacy as the adeno-based, protein-based or mRNA vaccines.”

In India, hospitalisations have not risen despite the detection of four BF.7 cases in the last few months, indicating that Indians are better protected because of their natural immunity from infection along with vaccine coverage.

Dr Babu said the current impact in China is not due to the variant’s properties per se. “Delta was fatal in India, but not in other countries. The Delta’s impact in India was not just because it was a serious variant, but because Indians had not been exposed to other variants during lockdowns. The moment we were exposed, Delta took the toll,” he says. “Omicron didn’t cause high hospitalisations later, not because Omicron was mild, but we had developed immunity by then.”

Read | India doing fine, do not expect surge in cases due to Omicron's sub-variants XBB, BF.7: Virologist

Rohan Pais and Chitra Pattabiraman from the Infectious Disease Research Foundation said that the earliest reports of BF.7 globally are from January-February this year. So far, 47,881 BF.7 cases have been identified, most commonly in Germany, USA and Denmark. But this variant is present in less than 0.5% of sequences collected from areas where it had been detected. “Current evidence does not suggest concern for this variant over and above the parent lineage,” said Pais and Pattabiraman.

They also point out that BF.7 is only among the 10 Omicron sub-variants reported from China to the global science initiative GISAID in December. “It is unclear how the epidemic has been attributed to BF.7 alone, as publicly-available data and research suggest the co-circulation of multiple Omicron lineages in China and across the world,” they said.

Dr Babu also said reliable data on China is needed from organisations like WHO. “Though BF.7 is said to be dominant there, we are not sure whether this is real-time data.”

The concern now is not about BF.7 itself, but whether the rapid infections in China can lead to the rise of new variants and whether our immunity will be sufficient to tackle those, said Dr Babu. “There is no need to panic. But we have to be proactive in understanding the genetic lineages in China, and increased genomic sequencing here can possibly identify any emerging variant.”

A new variant is considered a Variant of Concern (VoC) only if it is not susceptible to current treatments, isn’t responding to vaccines or if there is a change in its transmissibility or virulence, says Dr John Paul, Infectious Diseases Consultant at Sparsh Hospital. “Globally no VoCs have been detected recently,” he said.