*Why the “double mutant” B.1.617 is not as scary as it sounds. *

(Long tweet thread attached for anyone who wants to see the latest research on it. Note: click individually on each tweet to see the thread and links below it. Browsing alone will not bring up the whole thread)

I will list the highlights here.

1. The so called “double mutant” (wrong terminology) has been “divorced” and is now “single”. Among the two commonly discussed mutations L452R and E484Q* (it has, in fact, 13 of them), one has been lost and it is quite likely that the virus decided to “divorce” this mutation because it was not offering any “advantage”.

It has split into 617.1, 617.2 and 617.3. Of these, 617.2 is the “single version” and it is growing faster than the original.

(*Remember that E484Q is not the same as the immmune evasion mutation E484K)

2. Earlier research on B.1.617 (the “Indian double mutant variant”) had shown that both Covaxin and Covishield are effective, and now we have data that Pfizer vaccine also is affective against this.
3. In summary, B.1.617 is easily defeated by all available vaccines and is most likely not a variant of concern.
4. However most of the new variants that is B.1.1.7, B.1.617 are believed to be more transmissible – which means they can spread faster from person-to-person. None of them have been shown yet to increase individual mortality or evade vaccines. (of course if more people get infected, the total mortality will go up)
5. See my tweet today about the NEJM “real world” study from today from Qatar on how the (Pfizer) vaccine has ~100% efficacy against severe disease from the “South Africa variant” B.1.351 and B.1.1.7. This is one of the most important papers in pandemic history, because real world studies are more important than lab studies that are mostly based on viral neutralisation titres.
6. This correlates well with on-the-ground data from India, that people who have completed vaccination do not fall seriously ill with COVID-19.
7. Note: rare exceptions always exist when large populations are studied, remember that immune response to COVID-19 is extremely heterogeneous; HLA has a major role in antigen presentation and their subsequent recognition by T cells and B cells; HLA differences between individuals (and comorbidity) will explain this heterogeneity to a large extent.

(All my summary tweets are linked to their original papers)

Dr Rajeev Jayadevan
6 May