The Delta variant has mutated, meaning a new ‘Delta Plus’ variant is doing the rounds – both in India, where Delta first originated, but also the UK.
Here’s what we know so far about the mutation.
Where has Delta Plus been detected?
The mutation (AY.1) first came to light in India in April. Since then, it’s been spotted in three states: Maharashtra, Kerala and Madhya Pradesh. It has reportedly been labelled a ‘variant of concern’ by Indian health officials.
The variant has also spread to other countries including the UK, USA, Portugal, Switzerland, Japan, Poland, Nepal, China and Russia. Sky News reports that 41 cases have been sequenced in the UK.
Public Health England (PHE) confirmed to HuffPost UK that “cases are dispersed throughout England”. The health body said it is actively investigating cases and a small number of clusters.
PHE does not use the ‘Plus’ label and instead refers to it as Delta-AY.1. It is considered part of the Delta variant, rather than a new variant, which is why it isn’t classified as a variant under investigation or variant of concern here in the UK.
Dr Andrew Lee, Covid Incident Director at PHE, said additional control measures were put in place two weeks ago where cases of Delta Plus have been detected. “Active investigation of cases and clusters will ensure our public health response remains fast and proportionate,” he said.
How is the variant different?
The Delta Plus or AY.1 variant is the Delta (B.1.617.2) strain carrying the K417N mutation in the spike protein, says Francois Balloux, Professor of Computational Systems Biology and Director at University College London’s Genetics Institute.
K417N is an additional spike mutation of interest which was seen in the Beta variant, first detected in South Africa, and is now seen in a small number of Delta variant genomes in the UK.
Initial studies from India suggest the Delta Plus variant could be “even more transmissible” than the existing Delta variant, which is dominant in the UK and is 60% more transmissible than the Alpha variant that originated in Kent in 2020.
Randeep Guleria, director of the All India Institute of Medical Sciences (AIIMs), told India Today the variant is extremely transmissible, and suggested simply walking next to someone with the variant without a mask could lead to it spreading.
There are also concerns this particular variant could attach more easily to lung cells. Guleria said the Indian government is worried about the immune escape mechanism of Delta Plus. As such, studies are underway to determine whether vaccines are still effective against this mutation.
In the meantime, enhanced testing, contact tracing and vaccination are underway in areas in India where Delta Plus has been discovered.
Should we be worried?
“At this stage there is no particular cause for concern,” says Prof Balloux of the impact on the UK.
It has been found in several countries but “has remained at extremely low frequency”, with the exception of Nepal, he said, adding cases of Delta Plus in the UK remain “at a very low level” too.
“Given the tiny number of strains reported, nothing is known about the transmissibility, immune evasion or lethality of the Delta Plus strain,” he says.
“Though, given that it has remained at very low frequency everywhere where it has been identified strongly suggests it is not more transmissible than its Delta progenitor.”