New strains of the Covid variant found in India are deadlier and more infectious, the World Health Organisation has said on the country's coronavirus situation in a weekly update. It also says the potential impact of these mutations on the effectiveness of vaccines is uncertain.
The B.1.617 variant first detected in India in October and now found in 44 countries, has a higher rate of transmission and reduced susceptibility to neutralisation antibodies.
Around 0.1 per cent of the Covid-positive samples in India have been genome sequenced.
According to WHO, the B.1.17 variant found in UK and the India-dominant B.1.617 have "begin to wane in recent weeks", but worryingly, there are more dangerous mutations of the B.1.617 now - the B.1.617.1 and B.1.617.2.
"Preliminary analyses shows B.1.617.1 and B1.617.2 have substantially higher growth rate suggesting potentially higher transmissibility," says the WHO update.
"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)."
The organisation says the potential impact of the B.1.617 variants on the effectiveness of vaccines, medicines and on the chances of reinfection remains uncertain.
"Preliminary laboratory studies awaiting peer review suggest a limited reduction in neutralisation by antibodies; however, real-world impacts may be limited.
Some studies have shown the Pfizer and Moderna vaccines have shown "reduced effectiveness" against variants in India, says WHO.
"Preliminary evidence suggests potential reduced effectiveness of Bamlanivimab, a monoclonal antibody used for COVID-19 treatment, and potentially slightly reduced susceptibility to neutralisation antibodies," says the WHO paper.
On the other hand, an American expert has said that the Pfizer, Moderna and Johnson and Johnson vaccines are effective against the B.1.617 variant, based on data.
"The data is coming in, and it looks very encouraging that the US-approved vaccines, the Pfizer, the Moderna, the J&J, do have effectiveness against this variant called B.1.617," Dr Francis Collins, Director of National Institute of Science, was quoted as saying by Press Trust of India.
In April, the variant B.1.617.1 accounted for 21 per cent of sequenced samples from India and B.1.617.2 accounted for seven per cent.