Thread by @TejSowpati

So much misinformation and confusion about the circulating #SARSCoV2 variants in India. Leaving aside that the names are scientifically inaccurate, #B1618 ("Bengal variant") is NOT the #tripleMutant. I will try to summarize the basics in this thread.

(1/n)

B.1.617: characterized by more than 15 mutations, it got dubbed the "double mutant" because of two spike mutations, L452R and E484Q, which were mutations of concern because of their immune escape properties, and possible high infectivity.

https://twitter.com/vinodscaria/status/1380710693452738563?s=20

(2/n)

What's more, there are several sequences of B.1.617 which don't have the E484Q mutation, now sampled in India and elsewhere, which means it's not even the OG "double mutant" anymore.

(3/n)

Triple Mutant: Again, WRONG name, because it has many more defining mutations. Dubbed "triple" because in addition to the two mutations, it also has V382L in its Spike. This is a sub-lineage of B.1.617, found mainly in MH samples and also a bit in other states.

(4/n)

The extra mutation, V382L, is just a mutation of "interest" at this point because it's in the RBD of Spike, and was listed as a low frequency in the US. So far, its frequency seems to remain low and constant.

biorxiv.org/content/10.110…

(5/n)

Whether V382L causes more spread, let alone "more lethal" as touted by the news, remains to be studied. But given its behavior elsewhere so far, it probably less likely to be "destructive".

(6/n)

And lastly B.1.618: First sampled in WB late Oct 2020, it has nothing to do with B.1.617, except for a couple of shared variants that all SARS-CoV-2 strains have at this point such as D614G.

https://twitter.com/vinodscaria/status/1384375746190184452?s=20

(7/n)

The main concern with #B1618 is that it's found in growing proportions in WB, and has the Spike del145-146 as well as E484K, both of which are known immune escape mutations. E484K in particular was seen before in both B.1.351 and P.1 lineages.

https://twitter.com/vinodscaria/status/1384375760035532801?s=20

(8/n)

In short, the names of "double" and "triple" mutants are wrong and misleading. And they have no connection to the lineage seen in WB. I have seen even respected news sources getting this wrong. We have enough problems currently, without adding misinformation to the list.

(9/n)

I urge journalists to do a bit more research before writing fear-mongering articles. If something is not clear, please do get in touch with the scientists whose tweets you are quoting. I'm positive they will be happy to explain things in more detail.

Thank you 🙏

(10/10)