Footprint of B.1.617 now spreads to 44 countries

Three lineages of a variant of the Sars-Cov-2 virus first seen in India now account for 66% of all samples tested in the most recent 45 days, according to data from India submitted to a global repository (GISAID) even as other data submitted to the same repository indicates that the variant has now spread to several parts of the world with a rapid increase in prevalence in several regions.

The data adds to evidence that the variant could be more infectious, pointing to the public health challenge across the world, but in India, especially, where many scientists and epidemiologists believe that variants such as this one, named B.1.617, may be behind the surging second wave of the coronavirus disease pandemic that has seen the country add almost 10 million cases of Covid-19 in the past month, with the last five being added in two weeks.

The World Health Organization (WHO) said in its weekly Covid-19 epidemiology update that the B.1.617 variant with its three sub-lineages has been found in 44 countries.

While studies on the extent of protection offering by existing vaccines against the variant continue, preliminary research in India suggests that vaccinations using the two vaccines widely used in the country do continue to protect even those infected by

the variant against severe illness and death.

The variant’s rapid rise has now triggered alarm in several countries, including the UK which has found it to be responsible for the second highest number of infections and where experts have urged the government to rethink the May 17 lifting of curbs.

B.1.617 -- first detected in India last October and described by Indian officials in late March by the misnomer “double mutant” -- was classified as a variant of concern (VOC) globally by WHO on Monday, and a particular sub-lineage – the B.1.617.2 – was similarly flagged by authorities in the UK last week.

“In consultation with the WHO Sars-CoV-2 Virus Evolution Working Group, WHO has determined that viruses within the lineage B.1.617 have been characterised as a VOC,” the world body explained in its Covid-19 Weekly Epidemiological Update released on Wednesday. WHO said its decision was based on two reasons: “B.1.617 sub-lineages 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)” and “preliminary evidence suggests potential reduced effectiveness of Bamlanivimab, a monoclonal antibody used for Covid-19 treatment, and potentially slightly reduced susceptibility to neutralisation antibodies (limited evidence available for B.1.617.1).”