Delta variant picks up a new mutation
Scientists are closely watching a new mutation that has been found in some Delta variant samples – the particular change has been seen in other variants shown to be somewhat more resistant
WHAT IS THE CONCERNING FACTOR?
The Delta variant is a collection of around 13-15 mutations, of which several are of concern. At least four of these – D614G, E484Q, L452R and P681R – are known or are being investigated for making the Sars-CoV-2 better able to spread, cause more serious disease or resist immunity from a past infection or vaccine. Now, it has picked up a mutation known as K417N. Delta with the K417N mutation has been designated as AY.1 for now, and is informally referred to as ‘Delta plus’.
1 WHAT DO WE KNOW ABOUT K417N?
K417N is a mutation in the Spike protein, the portion of the Sars-CoV-2 that helps it latch on to and enter human cells. At a location coded as 417, the amino acid lysine (K) is changed to asparagine (N). In a study by researchers from Rockefeller University, K417N was among three mutations that diminished the potency of 14 of the 17 key neutralising antibodies produced after vaccination with mRNA doses.
2 WHICH OTHER VARIANTS IS K417N FOUND IN?
This mutation has also been found in the Beta variant (B.1.351 – seen first in South Africa) and some samples of the Gamma variant (P.1 – seen first in Brazil). Both these variants are known to be more resistant to immunity, but it is still being investigated which mutation in particular or what combinations of mutations do this.
3 HOW PREVALENT IS IT?
The AY.1 variant has been found in 159 samples worldwide, according to an analysis of GISAID data by outbreak.info. Of these, 8 have been found in India. All of these 8 cases were found between April 5 and May 15. Data from Nextstrain shows two clusters of the variant – one in the US and another spread over 8 countries in Asia and Europe. In the UK, the Public Health England – which carries out the most genome sequencing of all agencies worldwide – said the first 5 cases there were sequenced on April 26 and were contacts of people who travelled from, or through, Nepal and Turkey.
4 WHERE DID IT ORIGINATE?
It is unclear. One of the earliest recorded samples was collected on April 5 from a man in Maharashtra. Reports this month also said that Japanese authorities found this variant in 13 people who came from Nepal after an Everest expedition.
5 HOW WORRYING IS IT?
The closest major analysis is by PHE, which has found 36 cases of AY.1. Of these, it could determine vaccination status of 27 – only 9 had received vaccines and 2 had both doses. The preliminary findings don’t yet suggest any major vaccine resistance.