GOOD NEWS—a mutation seen in a few #SARSCoV2 variants doesn’t seem to harm the Pfizer/BioNTech vaccine, finding “no reduction in neutralization activity against virus”.

HOWEVER—did not yet test for worrisome E484K mutation, which many experts say might. https://www.statnews.com/2021/01/08/pfizer-biontech-vaccine-mutation-contagious/

2) A colleague of mine, @AliNouriPhD, wrote a post on a recent reinfection case involving the E484K mutation. We know it can “escape” many current neutralizing antibodies. https://twitter.com/alinouriphd/status/1347016588579508224

3) What do we mean by “escape neutralizing antibodies”? It means antibodies known to bind the common type of the #SARSCoV2 virus no longer bind to the mutated version. And that is what we are noticing with the E484K mutation that’s in receptor binding domain. ( @jbloom_lab credit)

4) that said, within the same person, this fraction that escape antibodies also changes over time. On day 18, there was a lot of escape, but on day 94, much less. Hence lots of uncertainty about vaccine or MAB drugs long term.

5) That said, BioNTech founder says it only takes them 6 weeks to synthesize a new mRNA vaccine for any new variant. Tricky question is how much clinical testing needs repeated / how long before it can be deployed. Another 10 months w/ Phase 3 mega trial again? Or shorter P1&2?

6) But the E484K can cause large 10x or more reductions in neutralization in some. (Wildtype= common #SARSCoV2). That is a huge huge reduction.

7) To be clear—“neutralization” = stopping the virus. So the E484K showing a 10x reduction of neutralization of the virus by various antibodies compared to wildtype (common #SARSCoV2) is a very bad thing. It means the virus with E484K is worrying for “immune escape” https://twitter.com/jbloom_lab/status/1346442000472580098

8) And so which #SARSCoV2 strain has the E484K mutation? The South Africa variant - aka 501.V2 or the B.1.351 lineage variant. This is why we are worried about that B1351 variant so much for vaccine escape potential. https://twitter.com/jbloom_lab/status/1346442016092082176