'Indian strain' of COVID-19 discovered in over 44 countries now: WHO

The Indian variant, or the B.1.617 strain, of the coronavirus has been discovered in over 44 countries now, the WHO stated in its weekly epidemiological report released on May 11. Though there is no concrete evidence yet, the 'double mutant' strain is feared to be contributing to the deadly surge of cases in India. It was earlier classified as a “Variant of Concern (VoC)” at the global level.

The B.1.617 variant has three spike protein mutations. E484Q and L452R, in the crucial spike protein part of the pathogen, increase its transmissibility. The third mutation—P681R—allows the virus to enter cells more efficiently. It is not believed to feature the E.484K mutation found in the South African variant of the virus, which could help the virus dodge a person's immune system.

The B.1.617 was first detected in October. Last month, UK's Public Health England (PHE) had categorised two further subtypes to that B.1.617.2 and B.1.617.3. Health authorities in England had elevated one subtype to a VoC following a rise in the number of cases in the UK and evidence of community transmission.

In its latest report, WHO stated that the B.1.617 sublineages appear to have higher rates of transmission, including observed rapid increases in prevalence in multiple countries (moderate evidence available for B.1.617.1 and B.1.617.2). The organisation also said that preliminary evidence suggested potential reduced effectiveness of Bamlanivimab, a monoclonal antibody used for COVID-19 treatment, and potentially slightly reduced susceptibility to neutralisation antibodies.

The WHO stated in the epidemiological survey: "Prevalence of several VOCs including B.1.1.7 and B.1.612 sublineages increased concurrent to the surge in COVID-19 cases reported in India. While B.1.1.7 and B.1.612.1 variants have begun to wane in recent weeks, a marked increase in the proportion of viruses sequenced as B.1.612.2 has been observed over the same period. Since the identification of these variants through late April 2021, B.1.617.1 and B.1.617.2 accounted for 21 per cent and 7 per cent of sequenced samples from India, respectively."