B.1.617 variant of concern at global level: WHO

NEW DELHI: The coronavirus B.1.617 is a global variant of concern, the World Health Organization said on Monday as scientists reported new clues that suggest the mutations first seen in India may be making the pathogen more transmissible.

In recent days, new assessments disclosed by scientists has shown that the B.1.617 and its particular lineage B.1.617.2 have rapidly expanded their footprint in some regions, and in lab tests show that they can lead to a high viral load – although it isn’t clear yet if they are more resistant to vaccines or immunity from a past infection.

“There is some available information to suggest increased transmissibility of the B.1.617,” Maria Van Kerkove, the WHO’s lead on Covid-19, told reporters on Monday, also pointing to early studies. “As such we are classifying this as a variant of concern at the global level,” she said, adding that more details would be provided in the WHO’s weekly epidemiological update on Tuesday.

The variant is being considered as one of the reasons why India has been overwhelmed by a surge in cases. Now, it will be added to the list containing three other variants of Covid-19 -- those first detected in UK (B.1.1.7), Brazil (P.1) and South Africa (B.1.351) -- which the WHO has classified as being “of concern”.

They are seen as more danthat gerous than the original version of the virus by being more transmissible, deadly or able to get past vaccine protections.

When it comes to the B.1.617 variant, Van Kerkove stressed that for the time being “we don’t have anything to suggest that our diagnostics or therapeutics and our vaccines don’t work”.

In a study published late on Sunday, researchers led by teams from Cambridge reported the B.1.617 variant. Among the assessments they carried out was the case analysis of 33 staff members of a Delhi health facility who were infected by the coronavirus after having been vaccinated, and how these mutations behaved when recreated in the lab.

“The loss of neutralisation of B.1.617 (by vaccinated serum) has likely contributed to an epidemic wave in India where background infection to the Wuhan-1 D614G in 2020 was between 20-50%,” said the authors in the study, which is yet to be peer reviewed.

The scientists also flagged a particular mutation, which has also been seen in the UK variant, as having some implication on how the disease develops. “We find that P681R is associated with enhanced capacity to induce cell-cell fusion and syncitia formation, and that P681R alone confers this ability on the B.1.617.1 spike with RBD mutations L452R and E484Q,” they say.

Public Health England on Friday announced it has found B.1.617.2 to have spread in Britain in a way similar to the early days of B.1.1.7, which triggered runaway outbreaks in several regions that had to enter a lockdown in order to contain it.

New data seen in India too suggested this may be true. As per the latest genome sequencing data shared by Indian labs with the global repository GISAID - B.1.617.1 and B.1.617.2 accounted for 58% of all samples submitted in the last 30 days.

B.1.617 VARIANT IS BEING CONSIDERED AS ONE OF THE REASONS WHY INDIA HAS BEEN OVERWHELMED BY A SURGE IN CASES